POLLUTION STATUS OF THE SUNGAI SKUDAI RIVER SYSTEM
THROUGH HEAVY METALS
VYNAVI A/P THANAPALASINGAM
A thesis submitted in fulfilment of the
requirements for the award of the degree of
Master of Science (Chemistry)
Faculty of Science
Universiti Teknologi Malaysia
SEPTEMBER 2005
PSZ 19 :16 9 (Pind. 1/97)
UNIVERSITI TEKNOLOGI MALAYSIA
BORANG PENGESAHAN STATUS TESISi
JUDUL : POLLUTION STATUS OF THE SUNGAI SKUDAI RIVER
SYSTEM THROUGH HEAVY METALS
SESI PENGAJIAN :
Saya
2005/2006
VYNAVI A/P THANAPALASINGAM
(HURUF BESAR)
mengaku membenarkan kertas projek ini (PSM/Sarjana/Doktor Falsafah)* ini disimpan di Perpustakaan
Universiti Teknologi Malaysia dengan syarat-syarat kegunaan seperti berikut :
1.
2.
Tesis ini adalah hakmilik Universiti Teknologi Malaysia.
Perpustakaan Universiti Teknologi Malaysia dibenarkan membuat salinan untuk tujuan pengajian
mereka.
Perpustakaan dibenarkan membuat salinan tesis ini sebagai bahan pertukaran antara instituisi
pengajian tinggi.
** Sila tandakan ( 9 )
3.
4.
SULIT
(Mengandungi maklumat yang berdarjah keselamatan atau
kepentingan Malaysia seperti yang termaktub di dalam AKTA
RAHSIA RASMI 1972)
TERHAD
(Mengandungi maklumat TERHAD yang telah ditentukan oleh
orgainisasi/badan di mana penyelidikan dijalankan)
TIDAK TERHAD
9
Disahkan oleh
(TANDATANGAN PENULIS)
(TANDATANGAN PENYELIA)
Alamat Tetap :
NO.2, TMN. NILAM
PROF. DR. ALIAS BIN MOHD. YUSOF
43800 DENGKIL,
SELANGOR DARUL EHSAN .
Tarikh
:
CATATAN : *
**
8 SEPTEMBER 2005
Nama Penyelia
Tarikh : __8 SEPTEMBER 2005 ___
Potong yang tidak berkenaan
Jika Tesis ini SULIT atau TERHAD, sila lampirkan surat daripada pihak
berkuasa/organisasi berkenaan dengan menyatakan sekali sebab dan tempoh
kertas projek ini perlu dikelaskan sebagai SULIT atau TERHAD.
*** Tesis dimaksudkan sebagai tesis bagi Ijazah Doktor Falsafah dan Sarjana secara
penyelidikan atau disertasi bagi pengajian secara kerja kursus dan penyelidikan,
atau laporan Projek Sarjana Muda (PSM).
“I hereby declare that I have read this thesis and in my
opinion this thesis is sufficient in terms of scope and quality
for the award of the degree of Master of Science (Chemistry)”
Signature
: …………………………
Name of Supervisor
: …………………………
Date
: …………………………
ii
I declare that this thesis entitled “POLLUTION STATUS OF THE SUNGAI
SKUDAI RIVER SYSTEM THROUGH HEAVY METALS” is the result of my own
research except as cited in the references. The thesis has not been accepted for any
degree and is not concurrently submitted in candidature of any other degree.
Signature
:
……………………………..
Name
:
……………………………..
Date
:
……………………………..
iii
Specially dedicated to,
My most beloved parents, sister and brother. Also my beloved husband and our dearest
daughter Sajne. May god bless us forever…
iv
ACKNOWLEDGEMENTS
First and foremost, I would like to express my heartfelt gratitude to my Project
Supervisor Prof. Dr. Alias bin Mohd. Yusof for the guidance, constant encouragements
and invaluable help given to me during my research study.
The assistance and co-operation during this study, provided by the staff of the
Faculty of Science, UTM, especially P.M. Dr.Noraini Abd Rashid, En. Hashim Baharin,
En. Hanan Basri, En. Mat Yassin Sirin, En.Lee Siak Kuan and En.Sulaiman Abdullah is
also deeply acknowledged. I was also most fortunate in receiving financial support from
UTM, transportation and other facilities in campus.
Special thanks are extended to Dr.Khalik Hj. Wood, Dr. Mohd. Suhaimi
Hamzah, Pn.Shamsiah Abd Rahman, En Halim and Pn.Jamaliah of Analytical and
Environmental Chemistry Department, Malaysian Institute for Nuclear Technology
Research (MINT), Bangi, Kajang, for their invaluable suggestions, technical assistance
and co-operation in performing analysis using ICP-MS and NAA facilities.The
assistance and co-operation rendered by Jabatan Alam Sekitar Johor, Jabatan Pengairan
dan Saliran Johor, Majlis Perbandaran Skudai, Majlis Perbandaran Johor Bharu and
Majlis Perbandaran Kulai are also thankfully acknowledged.
I would also like to thank both my parents for their prayers. The love, patience,
support and encouragement by family members are also gratefully acknowledged.
Finally, but not least, the author would like to thank all the wonderful individuals who
have, one way or another, generously contributed their knowledge, expertise and talents.
Special thanks are due to Mr. Mokhlesur, Mr. Mahmud, Ms. Sharmila, Ms. Caroljit and
Ms. Devagi for their assistance and companionship in the research work.
iv
ABSTRAK
Kajian ini telah dilakukan untuk menilai takat pencemaran logam berat di Sg.
Skudai. Sebanyak 16 stesen pemantauan telah dipilih dan persampelan air, tumbuhan
(Phragmites karka) dan sedimen telah dilakukan berdekatan kawasan perindustrian,
mengikut arah pengaliran sungai ke laut. Pensampelan telah dilakukan sebanyak enam
kali dalam tempoh sembilan bulan iaitu dari bulan November 2000 ke bulan Julai 2001.
Parameter kualiti air seperti suhu, pH, DO, BOD dan COD telah diukur dan hubungkait
statusnya kepada keadaan ekosistem sungai telah ditentukan. Keputusan yang diperolehi
telah dibandingkan dengan nilai piawai Interim National Water Quality Standards for
Malaysia (INWQS) dengan mengambil kira hidupan akuatik, sumber air minuman dan
pengairan. Teknik Analisis Pengaktifan Neutron (APN) dan Spektrometer Jisim Plasma Gandingan Aruhan (ICP-MS) telah digunakan untuk penentuan kepekatan logam
berat daripada sistem Sg. Skudai. Kaedah ini juga telah dikawal dengan menganalisis
bahan rujukan piawai Citrus Leaves dan Estuarine Sediment. Peratus perolehan bagi
data adalah lebih daripada 83 %. Kepekatan unsur As, Pb, Hg, Cr, Cu, Cd, Ni dan Zn
telah ditentukan. Tren bahan pencemar dan keputusan analisis statistik telah diperolehi
daripada keputusan analisis logam berat. Penumpukan unsur-unsur lain dalam sampel
juga adalah signifikan kerana wujudnya kawasan perindustrian yang banyak. Tren logam
berat dalam sampel air adalah Zn>Cu>Ni>Cr>As>Pb>Hg>Cd, di dalam sampel
tumbuhan ialah Zn>Cr>Cu>Pb>Ni>As>Hg>Cd dan di dalam sampel sedimen ialah
Zn>Cr>Cu>Pb>Ni>As>Hg. Keputusan yang diperolehi tidak melebihi 15-20 % ralat.
Korelasi wujud bagi unsur kromium dan unsur kuprum di dalam hubungan antara
tumbuhan dengan air dan tumbuhan dengan sedimen. Ini menunjukkan bahawa
tumbuhan ini sesuai dan mempunyai potensi sebagai penunjuk bio bagi kedua-dua unsur
ini. Manakala, unsur arsenik dan zink menunjukkan wujudnya korelasi dalam hubungan
antara air dan sedimen.
vii
TABLE OF CONTENTS
CHAPTER
1
TITLE
PAGE
TITLE
i
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENTS
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
xii
LIST OF FIGURES
xvi
LIST OF APPENDICES
xx
LIST OF SYMBOLS AND ABBREVIATIONS
xxi
INTRODUCTION
1
1.0 Background
1
1.1 Water Pollution
3
1.2 River Pollution
5
1.3 Industrial Effluents
8
1.3.1 Heavy Metals
12
1.3.1.1 Arsenic (As): Z =33
13
1.3.1.2 Cadmium (Cd): Z =48
16
1.3.1.3 Chromium (Cr): Z = 24
17
1.3.1.4 Copper (Cu): Z = 29
19
1.3.1.5 Lead (Pb): Z = 82
20
1.3.1.6 Mercury (Hg): Z = 80
22
viii
2
1.3.1.7 Nickel (Ni): Z = 28
25
1.3.1.8 Zinc (Zn): Z = 30
24
1.4 Aquatic Ecosystem
27
1.4.1 Aquatic Plant
30
1.4.2 Sediment
34
1.4.3 Heavy Metal Cycle in Aquatic Ecosystem
36
1.5 Research Objectives
38
1.6 Scope of Research
39
ANALYTICAL METHODS
40
2.0 Introduction
40
2.1 Inductively Coupled Plasma – Mass Spectrometry
40
2.1.1
The Origins, Realization and Performance
41
of ICP-MS Systems
2.1.2 Physical and Chemical Principles
42
2.1.3 General Uses and Application
44
2.1.3.1 State, Amount and Preparation of
44
Samples
2.1.4 Calibration and Standardization
45
2.1.5 Analysis Time
45
2.1.6 Quantitative Analysis
46
2.1.7 Limitation and Interferences
47
2.2 Flow Injection
2.2.1 Hydride Generation
2.3 Neutron Activation Analysis
49
50
51
ix
2.3.1 Principles of Instrumental Neutron
51
Activation Analysis
2.3.2 Decay
55
2.3.3 Nuclear Reactors
56
2.3.3.1 TRIGA Reactors
57
2.3.3.2 Rotary Specimen Rack (Lazy Susan)
57
2.3.4 Irradiation Containers and Sample
Encapsulation
58
2.3.5 Gamma Rays
58
2.3.6 Counting and Data Processing Facilities
60
2.3.6.1 Semiconductor Detectors
3
60
2.3.7 Qualitative Analysis
61
2.3.8 Quantitative Analysis
61
MATERIALS AND METHOD
62
3.0 Introduction
62
3.1 Study Area
62
3.1.1 Landscape
66
3.1.2 Climate
66
3.2 Selection of Monitoring Stations
66
3.3 Parameters Measured
69
3.4 Sampling Frequency
71
3.5 Sampling Methodology
73
3.6 Labware
75
3.6.1 Laboratory Apparatus
75
3.7 Sample Processing Equipment
76
3.8 Chemicals and Reagents
76
3.8.1 Standard Stock Solutions
3.8.1.1 Standard Stock Solutions for ICP-
77
78
MS and FI-MS
3.8.1.2 Preparation of Calibration Standards
78
3.8.1.3 Blank Solutions
79
3.8.1.4 Standard Stock Solutions for NAA
79
x
3.9
Standard Reference Materials
3.10 Sample Preparation
3.10.1 Preparation of Water Samples
3.10.1.1 Preparation of Water Samples for
80
81
81
82
NAA Analysis
3.10.2 Preparation of Plant Samples
83
3.10.2.1 Preparation of Plant Samples for
ICP-MS and FI-MS Analysis
3.10.2.2 Preparation of Plant Samples for
83
84
NAA Analysis
3.10.3 Preparation of Sediment Samples
85
3.10.3.1 Preparation of Sediment Samples
for ICP-MS and FI-MS Analysis
85
3.10.3.2 Preparation of Sediment Samples
86
for NAA Analysis
3.11 Analysis Using ICP-MS
86
3.11.1 Summary of Method for ICP-MS
86
3.11.2 Instrumentation for ICP-MS
87
3.11.3 Operating Conditions of ICP-MS
88
3.11.4 Instrument Performance
88
3.11.5 Standardization and Calibration
89
3.11.6 Experimental (Instrumentation of
FI-ICP-MS)
3.11.7 Data Acquisition and Processing
90
90
3.11.8 Flow Injection System
90
3.11.9 Hydride Generation System Conditions
92
3.11.10 Post-run Step
93
3.11.11 Standardization by FI-MS
3.12 Analysis Using Neutron Activation Analysis
93
93
3.12.1 Measurement of Activities of NAA
94
3.12.2 Detection Limits of NAA
94
xi
4
RESULTS AND DISCUSSION
95
4.0 Introduction
95
4.1 Water Quality Parameters Analysis
96
4.1.1
Temperature
96
4.1.2 pH
98
4.1.3
Dissolved Oxygen (DO)
99
4.1.4
Biological Oxygen Demand (BOD)
100
4.1.5
Chemical Oxygen Demand (COD)
102
4.2 Analysis of Standard Reference Materials
104
4.3 Precision and Accuracy
106
4.4 Concentration of Heavy Metals
111
4.4.1 Arsenic
121
4.4.2 Cadmium
131
4.4.3 Chromium
135
4.4.4 Copper
139
4.4.5 Lead
143
4.4.6 Mercury
147
4.4.7 Nickel
151
4.4.8 Zinc
154
4.5 Trend of Heavy Metal Concentration in Water
157
4.6 Trend of Heavy Metal Concentration in Plants
157
4.7 Trend of Heavy Metal Concentration in Sediment
159
4.8 Plants as Bio-indicators
160
4.8.1
Arsenic
162
4.8.2
Cadmium
162
4.8.3
Chromium
163
4.8.4
Copper
165
4.8.5
Lead
165
4.8.6
Mercury
165
4.8.7
Nickel
166
4.8.8
Zinc
166
4.8.9
Overall Discussion on Correlation Analysis
166
xii
5
CONCLUSIONS AND SUGGESTIONS
167
5.0 Conclusions
167
5.1. Suggestions
168
xii
LIST OF TABLES
TABLE NO.
1. 0
TITLE
PAGE
River Quality Monitoring Stations for Automatic
Continuous Monitoring (1995 - 2003), (Department of
7
Environment, 2003)
1.1
Heavy metals employed in major industries (ForstnerWittman, 1981)
11
2.0
Concentration of impurities in polyethylene and quartz
59
3.0
Types of industries under Sg. Skudai river system
68
3.1
Sampling locations along downstream route of Sg.
Skudai
70
3.2
List of parameters analyzed
72
3.3
Date of samplings carried out in the Sg. Skudai
72
3.4
Operating conditions of ICP-MS
89
3.5
Operating conditions used for the ELAN 6000 FI-ICP-
4.0
MS instrument
91
Results of water quality analysis
97
xiii
4.1
Overall average water quality results for the Sg. Skudai
97
river system
4.2(i)
Analytical results for elements in NIST-SRM 1572
Citrus leaves.Values are given in ppm (µg/g) and
correspond to the average and Stddev (relative standard
deviation) (n=3)
4.2 (ii)
105
Analytical results for elements in NIST-SRM 1646
Estuarine sediment. Values are given in ppm (µg/g) and
correspond to the average and Stddev (relative standard
deviation) (n=3)
4.3
Quality control standard sample solution results of ICPMS
4.4
111
Results of concentration of Cr in NIST-SRM 1646 for
every batch of NAA irradiation (recovery %).
4.7
110
Results of concentration of Zn in NIST-SRM 1572 Citrus
leaves for every batch of NAA irradiation (recovery %).
4.6(ii)
109
Estimated instrument detection limits and calculated
detection limits
4.6(i)
108
Analytical results of replicate analysis of standard
reference materials
4.5
105
111
Results of average elemental concentrations in the Sg.
Skudai river water for 6 samplings and at 16 sampling
locations
113
xiv
4.8
Results of average elemental concentrations in the plants
(Phragmites karka) from the Sg. Skudai river system for
6 samplings and at 16 sampling locations.
4.9
116
Results of average elemental concentrations for
sediments from the Sg. Skudai river system for 6
samplings and at 16 sampling locations
4.10
Results of previous studies from journals for elemental
concentrations in water
4.11
140
Average lead concentrations for water, plant and
sediment from the Sg. Skudai river system
4.18
137
Average copper concentrations for water, plant and
sediment from the Sg. Skudai river system
4.17
133
Average chromium concentrations for water, plant and
sediment from the Sg. Skudai river system
4.16
129
Average cadmium concentrations for water, plant and
sediment from the Sg. Skudai river system
4.15
126-127
Average arsenic concentrations for water, plant and
sediment from the Sg. Skudai river system
4.14
124-125
Results of previous studies from journals for elemental
concentrations in sediment
4.13
122-123
Results of previous studies from journals for elemental
concentrations in plants
4.12
119
146
Average mercury concentrations for water, plant and
sediment from the Sg. Skudai river system
149
xv
4.19
Average nickel concentrations for water, plant and
sediment from the Sg. Skudai river system
4.20
152
Average zinc concentration for water, plant and sediment
from the Sg. Skudai river system
155
4.21
Trend of heavy metals in water for the six samplings
158
4.22
Average heavy metals concentration in water for the six
samplings
158
4.23
Trend of heavy metals in plants for the six samplings
158
4.24
Average heavy metals concentration in plants for the six
sampling
159
4.25
Trend of heavy metals in sediments for six samplings
159
4.26
Average heavy metals concentration in sediments for the
six sampling
4.27
160
Correlation coefficient (r) value of concentration of
heavy metals in plants ,water and sediment
164
[vi
LIST OF FIGURES
FIGURE NO.
1.
TITLE
Movement of trace metals in
hydrological cycle
1.1
33
Close-up of inflorenscence of
Phragmites karka
1.4
32
Phragmites karka groZing naturally
by the river bank
1.3
14
An illustration of Phragmites karka
(Ahmad Azly, 19)
1.2
PAGE
33
Schematic presentation of metal
reservoirs and their interactions in
aTuatic and terrestrial system (Ahmad
%adri, 19).
37
2.
%lock diagram of an ICP ±MS system
43
2.1
Instrumentation of ICP-MS system
43
2.2
Schematic diagram illustrating the
seTuence of events for a typical (n,Ȗ)
reaction
2.3
3
Schematic set-up of gamma ray
spectrometer for use in INAA
6
[vii
3.
Jurisdiction %oundary of Sg. Skudai
river system
3.1
6
Pollution sources inventory map of
the Sg. Skudai river system and
sampling stations selected along the
river
3.2
67
Schematic diagram of an ICP-MS
instrument
3.3
Schematic diagram of FI-MS
92
4.
Average dissolved o[ygen values for
16 sampling points along the doZn
stream route of the Sg. Skudai river
system
4.1
11
Average biological o[ygen demand
values for 16 sampling points along
the doZnstream route of the Sg.
Skudai river system
4.2
12
Average chemical o[ygen demand
values for 16 sampling points along
the doZnstream route of the Sg.
Skudai river system
13
[viii
4.3
Average elemental concentrations for
Zater of the Sg. Skudai river system
4.4(i)
114
Average elemental concentrations for
plants (Phragmites karka) from the
Sg. Skudai river system
4.4
117
Average zinc concentrations for
plants (Phragmites karka) from the
Sg. Skudai river system
4.
11
Average elemental concentrations for
sediments from the Sg. Skudai river
system
4.6
12
Average concentrations of arsenic in
Zater, plant and sediment of the
sampling points.
4.7
13
Average concentrations of cadmium
in Zater and plant of the
sampling points.
4.
134
Average concentrations of chromium
in Zater, plant and sediment of the
sampling points
4.9
13
Average concentrations of copper in
Zater, plant and sediment of the
sampling points.
142
[i[
4.1
Average concentrations of lead in
Zater, plant and sediment samples of
the sampling points
4.11
147
Average concentrations of mercury in
Zater, plant and sediment samples of
the sampling points
4.12
1
Average concentrations of nickel in
Zater, plant and sediment of the
sampling points
4.13
13
Concentration of zinc in Zater, plant
and sediment of the sampling point
13
xx
LIST OF APPENDICES
APPENDIX
TITLE
PAGE
1
Water Quality Results for Each Sampling
187
2
DOE Interim National Water Quality Standards
for Malaysia
193
Data for Standard Reference Materials Citrus
Leaves and Estuarine Sediment
194
SRM Samples Results Using ICP-MS and NAA
Techniques
198
3
4
5
6
7
8
Results of Heavy Metal Concentration in Water,
Plant and Sediment for Each Sampling
Graphs of the Heavy Metal Concentration in
Water, Plant and Sediment for All Sampling
238
DOE Water Quality Criteria and Standards for
Malaysia
248
Results of T-Test for Each Sampling
249
220
xxi
LIST OF SYMBOLS AND ABBREVIATIONS
%
-
Percent
0
C
-
degree Celcius
0
K
-
degree Kelvin
mg
-
milligram
µg
-
microgram
mgL-1
-
miligram per liter
ppt
-
parts per trillion
ppb
-
parts per billion
Conc.
-
concentration
FI-MS
-
flow injection mercury system
HNO3
-
nitric acid
H2O2
-
hydrogen peroxide
ICP-AES
-
inductively coupled plasma atomic emission
spectrometry
ICP-MS
-
inductively coupled plasma mass spectrometer
IDL
-
instrument detection limit
INWQS
-
Interim National Water Quality Standards
MDL
-
methods detection limit
NAA
-
neutron activation analysis
xxii
QC
-
quality control
QCSS
-
quality control standard sample
RPM
-
round per minute
RSD
-
relative standard deviation
&HAPTER INTRODU&TION
.0
BaFkJrRXQG
The beginning of the new millennium seems to be characterized by a steadily
increasing attention being paid to the environment. The dramatic increase in public
awareness and concern about the state of the global and local environments has been
accompanied and partly prompted by an ever-growing body of evidence on the extent to
which pollution has caused severe environmental degradation. In addition, the costs of
these effects in the depreciation of resources, lost productivity and in cleaning up or
improving polluted environments are high and are increasingly occupying the attention of
governments and politicians around the world. The first worldwide meeting of heads of
state directed to concern for the environment took place at the Earth Summit, formally
known as the United Nations Conference on Environment and Development (UNCED) in
Rio de Janeiro in 1992.
A widely used definition of pollution is the introduction by man into the
environment of substances or energy liable to cause hazards to human health, harm to living
resources and ecological systems, damage to structures or amenity, or interference with
legitimate uses of the environment (Alloway and Ayres, 1993). Recently, adverse
environmental effects like species extinction, loss of forest systems, acid rains, global
warming, ozone depletion, hazardous waste disposal problems, frequent and intense ecoaccidents are also on the rise. Although these problems are very important for the future of
mankind, it is pollution, which arouses the most interest. This is because people realize that
pollution impacts on them directly through effects on their health, their food supply, the
degradation of buildings, and other items of cultural heritage, as well as overt effects on
forests, rivers, coastlines and ecosystems that they are familiar with. A major concern about
these pollutants is that they bio- accumulate in the food chain. One of the horrifying
2
tragedies that brought the world’s attention was the outbreak of the itai-itai disease that
resulted from cadmium ingestion experienced by Japan in the late 1960s (Sax, 1974).
Man and his environment are related to each other and man needs everything from
his environment, involving air, water, food, fuel and material resources. On the contrary,
environmental pollution is an unfavourable alteration of our surroundings, which may result
in loss of recreational facilities, loss of agricultural products, contamination of the air,
contaminated drinking water or loss of fresh water fish as a source of food. It comes about
as a by-product of man’s actions in which he directly changes energy patterns, radiation
levels, chemical and physical constituents of our air and water (Hall and Morrison, 1978).
Furthermore, studies showed that the endurance of ecosystems to bear stresses put upon
them by human activities has exceeded beyond limits, which has imbalanced the
environmental equilibrium. Mercury vapours in pesticides caused injuries to vegetation and
damage to crops in Los Angeles and the loss have been estimated at $ 500 000 yearly (Iqbal
and Qadir, 1989). In Malaysia, Yusof et al. (1995), pointed out that the bay areas of the
south of Johore can be categorized as the most polluted with heavy metals and localized
species are at risk of taking in these elements, leading to a lethal dose.
Apart from that, most environmental pollution is insidious and its harmful effects
only become apparent after long periods of exposure. Many people are exposed to
pollutants, which may cause cancer ten or twenty years later, without realizing it. Hamilton
and Wetterhahn (1988) reported that humans exposed to chromium compounds are prone to
diseases like asthma, lung and nose cancer and also skin allergy. Likewise, rivers can
become increasingly polluted and species die out without many obvious signs, at least in
the early stages.
During the Industrial Revolution in the 19th century, the River Irwell has been
considered one of the most polluted rivers in Europe, suffering from organic and inorganic
pollution unable to sustain life (Dixit and Witcomb, 1983). For this reasons, environmental
monitoring has become recognized as being vitally important in detecting where insidious
pollution is occurring, the pollutants involved and the sources from which they came.
3
.
:ater PRllXtiRQ
Water is an extraordinary chemical compound of absolutely fundamental
environmental importance. It is often being described as ‘the universal solvent’ or ‘the
liquid of life’. The earth’s water resources, ‘the hydrosphere’, consists of the oceans and
seas, the ice and snow of the polar regions and mountain glaciers, the water contained in
surface soils and underground strata, lakes, rivers, and streams. It can be said that the
waters of the hydrosphere were of natural quality until the Industrial Revolution in Europe
and North America initiated the development of technology driven by the energy of the
fossil fuels, coal and oil. Now the entire hydrosphere is contaminated by the polluting
activities of man (Harrison, 1992).
Water covers some 71% of the earth’s surface and is itself the medium for several
different ecosystems. All natural elements are soluble, at least in trace amounts, and all are
found in natural water at some place on the earth’s surface. Water is a major reservoir for
storing nutrients and other biologically important materials, and it is the main medium in
which these materials move from the abiotic to the biotic part of the ecosystem (Clapham,
1983). Philips, (1989) reported that inorganic arsenic is taken up rapidly by phytoplankton
and this represents an important route for the introduction of the element into aquatic food
web. In addition to that, water plays another, more material role for man. It carries away his
wastes. Natural water can purify some of these wastes; it can dilute others until they are
harmless; and it can carry the rest out of sight. But with the incessant growth in the world
population and industry, one city’s wastes become the next city’s drinking water.
Apparently, natural purification breaks down, fish die, odours form, diseases are
transmitted, and the central medium of all life becomes a garbage-filled carrier of stinking
death (Giddings, 1973).
Over the past decades, the natural quality of watercourses has been altered by the
impact of various human activities and water uses. Most pollution situations have evolved
gradually over time until they have become apparent and measurable. Recognition of a
pollution problem, usually took considerable time, and application of the necessary control
measures took even longer time. However, medieval reports and complaints about
inadequate excreta disposal, foul and stinking watercourses within overcrowded cities, and
other similar problems were an early manifestation of water pollution (Meybeck et al.,
1989). Several studies on the impacts of such activities on water quality in Malaysia have
4
been reported. Law (1980) has studied the effect of sewage by domestic discharge in the
Sg. Kelang where high levels of faecal coliform counts have been recorded. Meanwhile, the
Ministry of Environment had reported in November 1995, that two out of three rivers in the
country are polluted. Only 28 % of rivers are classified as clean. River water quality in the
country had deteriorated by 1.2 % per year in the last decade. Industrial wastes were the
major source of pollution (Consumers Association of Penang - Sahabat Alam Malaysia,
1996). As for heavy metal pollution, in the year 1996, 53 rivers were polluted with
cadmium, 44 rivers with ferum, 36 rivers with lead, 24 rivers with mercury and copper and
4 rivers polluted with chromium and zinc, according to Kadaruddin (2000).
The chemical and physical forms of water pollutants are even more varied than are
pollution sources. One sewer outfall can put thousands of chemical compounds into the
water. The array of specific water pollutants is so wide that to study them rationally we
must classify them into groups. There are two broad types of water pollution. In one, man
simply adds something to the water that was already there in moderate amounts, such as,
microorganisms, organic wastes, plant nutrients, sediments or silts, inorganic minerals,
acids and bases, heat, radioactivity and heavy metals. In another, man adds chemicals and
materials strictly of his own invention that are new entrants into the environment, such as
pesticides and industrial chemicals (Giddings, 1973). Pesticides and herbicides industries
are two industries that often discharge arsenic in its production wastes (Burrell, 1974).
A few water bodies were polluted rather seriously. Some surface waters, ground
waters, and soils in urban areas were polluted by industrial wastewater or inappropriate
irrigation with wastewater. Pollution is a killer of plants, animals and human life. Its effects
have been witnessed as toxic substances in the water killing plants and animals in our fresh
waters. The result is an unpleasant environment for man to live in and since these waters
are in some instances the supply of drinking water, the pollution could ultimately be
dangerous to human life (Hall and Morison, 1978). The threat to human health and welfare
posed by surface water pollution has two principle facets: (1) direct effects, which may
result from the consumption of contaminated water supplies and food, and (2) indirect
effects, which may result from the impact of pollutants on the quantity and quality of
aquatic organisms used for human food, the recreational use of water, the aesthetic quality
of the aquatic environment, and the integrity of the biosphere (Weber, 1981).
5
In early days of national development when resources seemed vast and unlimited,
deliberation on the choices of development alternatives did not seem necessary. Today it
has become clear that we all live in one biosphere within which space and resources are
limited and choices based on sound environmental principles must be made at every turn.
Failure to include environmental considerations in resource utilization will inadvertently
result in adverse environmental consequences.
One such resource that needs protection and conservation is water, which is very
important for development. Its quality has to be maintained for the various uses it is put to.
Of all natural environmental resources, water is the most severely threatened by pollution.
At the same time it is one of the greatest needs of society, as, life ends wherever there is
insufficient clean fresh water. Malaysia has assessed this position with foresight and taken
early steps to protect its aquatic environment. This is evidenced by the adoption of the
Environmental Quality Act 1974, and also the creation of the Division of Environmental to
administer the Act (Department of Environment, 1985).
.2
RiYer PRllXtiRQ
Rivers in Malaysia have made immense contributions to the overall development of
this country. They have provided power generation, water for domestic, agricultural and
industrial consumption and have served as means of transportation and communication for
the people. The towns and cities of Malaysia began as settlements along rivers while river
mouths provided refuge and became homes to fisherman who braved the open seas to seek
their living (Department of Irrigation and Drainage, 1992).
Therefore, rivers are an invaluable natural resource, which contribute to the survival
of mankind and development of nations. Rivers, as the arteries of natural water resource,
supply water for domestic and industrial usage and irrigation. In Malaysia, water is needed
for drinking water supply, sanitation, agriculture, industrialization, urbanisation, fisheries,
transportation, recreation and to produce hydroelectric power. The demand for water
increases about 4% yearly and it is estimated that about 20 billion per meter square (b/m3)
of water is needed by the year 2020. The demand for domestic and industrial use is
approximately 0.8 b/m3 annually during 1980s and this figure is expected to rise up to 4.9
6
b/m3 annually from year 2000 onwards. Annual demand for industrial and domestic use will
increase up to 5.8 b/m3 and the water demand for agricultural purpose will be about 13.2
b/m3 by the year 2020 (Consumers Association of Penang - Sahabat Alam Malaysia, 1996).
Apart from the traditional role of drainage, river transportation and food resource,
rivers also have great potential for recreations and tourism. In order to serve the abovementioned roles and functions, rivers need to be conserved and should remain clean and
unpolluted. For example, the Sg. Langat in Selangor plays a significant role in ecology,
provide potable water to residents, supply industries and agricultural areas with water for
manufacturing and agricultural production, provide other services such as recreational sites
and habitats for fish and other aquatic wildlife (M. Nordin and L. A. Azrina, 1998). In
India, the Ganga River has many beneficial uses such as bathing, swimming, public water
supply, agriculture, industry, fish culture, wildlife boating and non-contact recreation
(Devendra Swaroop Bhargava, 1983).
During recent years serious concern has been voiced about the rapidly deteriorating
state of freshwater bodies with respect to trace metal pollution. It is also reported that
serious metal pollution could result from the discharge of unregulated effluents into the
natural freshwater bodies. In Brazil, Veado (1997) pointed out that wastewaters from about
24 legal and several clandestine industries are discharged into the Das Velhas River. In
spite of environmental controls carried out by multinational companies, pollution from
smaller, sometimes clandestine, industry is still rife and this is the largest environmental
problem. Earlier base-line studies have identified elevated levels of certain trace metals in
freshwater systems around the world, especially rivers arising mainly from agricultural and
industrial processes (Tariq et al., 1996).
In Malaysia, like other countries of the world, the level of metal pollution of
freshwater bodies, especially the rivers, is no longer within safe limits for human
consumption. In the year 2002, the Department of Environment (DOE) reported that
industries such as textile, metal finishing and electroplating, food and beverages, and
animal feed could not achieve more than 65% compliance. Some industries were operating
either without effluent treatment system (ETP) or with inefficient ETP. These industries
had difficulty in complying with parameters such as nickel, copper, lead, zinc and iron
(Department of Environment, 2002). In Malaysia there are not less than 1500 rivers. Rapid
population growth, urbanization and industrialization have subjected some of these rivers
7
to increasing stresses giving rise to loss of firm yield of water and power, sedimentation,
flooding, water pollution and environmental deterioration. The Department of Environment
National River Water Monitoring Programme got started in 1978, but since 1995, it was
contracted out to Alam Sekitar Malaysia Sdn Bhd (ASMA) under a privatisation
arrangement. In 2003, 926 stations located within 120 river basins in Malaysia were
monitored. Out of these 926 monitoring stations, 412 (44.5 %) were found to be clean, 448
(48.4 %) slightly polluted and 66 (7.1 %) polluted. Automatic water quality monitoring
stations monitored river quality changes on a continuous basis at Sg. Perai (Pulau Pinang),
Sg. Selangor (Selangor), Sg. Kelang (WPKL), Sg. Linggi (Negeri Sembilan), Sg. Melaka
(Melaka), Sg. Skudai (Johor), Sg. Perak (Perak), Sg. Keratong (Pahang), Sg. Terengganu
(Terengganu) and Sg. Sarawak (Sarawak). Under the pollution prevention and Water
Quality Improvement Programme, five (5) additional automatic stations were installed at
Sg. Langat (Selangor), Sg. Batang Benar (Negeri Sembilan), Sg. Labu (Negeri Sembilan),
Sg. Putat (Melaka) and Sg. Rajang (Sarawak) (Department of Environment, 2003). This is
clearly indicated in Table 1.0.
TaEle . 0 : River Quality Monitoring Stations for Automatic Continuous Monitoring
(1995 - 2003), (Department of Environment, 2003)
Year
5 6
RiYer BaViQ
8
2000
200
2002
2003
2
4
6
8
10
10
10
12
12
2
4
6
8
10
10
10
12
15
NXmEer RI the
AXtRmatiF &RQtiQXRXV
MRQitRriQJ StatiRQV
Domestic sewage, palm oil mills, rubber factories, industrial wastewater and
piggeries are the principal contributors of pollutants in Malaysia (Maketab Mohamed,
1993; Department of Environment, 1998). Severe seasonal depletion of the oxygen levels in
major rivers caused a general degradation of their quality and increased difficulties in
drinking water treatment. Overloading with biodegradable organic wastes from riparian
municipalities and industries was mainly to be blamed. The gradual increase of heavy metal
concentrations in sediment and in the water of rivers also reached alarming proportions.
8
In addition, the trace metals in such waters may undergo rapid changes affecting the
rate of uptake or release by sediments thus influencing living organisms via the watersediment chain.
.3
IQGXVtrial EIIlXeQtV
Man is responsible for releasing vast quantities of many different chemical
substances into the environment each year; the majority of these anthropogenic substances
are waste products generated by industry and society consuming the manufactured goods.
Man-made fabrics and fibres, pharmaceuticals, fertilizers, pesticides, paints, and building
materials, as well as chemicals for industrial processes, are just some of the products of the
chemical industry that are integral to almost every aspect of modern living (McCaull and
Crossland, 1974).
It is well known that the main polluters of water bodies and rivers are heavily
industrialized cities. At present industrial wastes are prevalent in the composition of the
wastewaters of giant industrial cities. Furthermore, the industrial era of the nineteenth
century resulted in an acceleration of the use of natural substances such as As, Cd, Hg, Pb,
Zn, S, etc., that could eventually be released to the aquatic environment. The current
production and use of tens of thousands of synthetic chemicals inadvertently resulted in the
release of these substances into the general environment. Although industry uses much less
water than agriculture, it causes more pollution. Most of the water is used for cooling and
cleaning and, although more than 80 per cent of it is returned immediately to the natural
water cycle, it is often polluted with by-products of the manufacturing process and other
waste material (Hester, 1983). Concentrated effluents from manufacturing and industrial
production plants have added hazardous substances to natural water courses and reduced
their ability to sustain aquatic life.
Often, when the environmental issues associated with industry are considered, it is
common to focus on the wastes generated during the manufacturing process and the
associated environmental problem by the physical state of the waste. Industrial
contributions to environmental problems can arise from each of the steps of the life cycle of
its products. Subsequently, industry can create additional adverse environmental impact
9
while processing these materials into products and in the packaging and distribution of its
products (Palmer, 1995). Variations in water flows, manufacturing process and production
regimes result in effluent discharges which are seldom simple and whose constituents are
changing with time. The entry of an effluent will affect the aquatic environment to some
degree. A study in India revealed that the phsico-chemical characteristics of the water are
being altered in the industrial area (Joy et al., 1990). Besides that, Bais et al. (1991),
reported effects of industrial effluents on the reduced number of zooplankton in the River
Dhasan in India.
Water pollution by toxic chemicals present in industrial waste effluents is a
worldwide problem now. Both developed and developing countries are seriously affected
due to this water pollution. Consequently, major water pollution in Malaysia is also caused
by the discharge of industrial effluents. Many industries discharge wastes containing
different inorganic compounds including heavy metals into natural freshwater bodies
without prior treatment. However, the point sources of pollution in Malaysia come in the
form of forest cleaning and earthworks, industrial effluents and wastes typically the agrobased industrial point sources (namely rubber and oil palm mills), domestic or animal
farming sewage (Department of Environment, 2002). The Department of Environment
(2002) also reported that industries such as tannery, chemical-based, electrical and
electronic industries achieved average compliance of 81 %, 85 % and 86 % respectively.
However, industries like paper, textile, metal finishing and electroplating, food and
beverages, and animal feed could not achieve more than 65 % compliance. In 2003, 129
premises or companies were taken to court and fined a total of RM 1 901 300.00 for
offences under the Environmental Quality Act, 1974. Out of the total number of cases, 55
(43%) cases involved offences for polluting inland waters through discharges of effluent
above the stipulated standard under section 25(1) of the Environmental Quality Act, 1974
(Department of Environment, 2003).
Furthermore, industries designated with the sources of heavy metals pollution are
many and varied. One such listing is presented here in Table 1.1. The ten most common
toxic heavy metals are shown to be associated with the twelve groupings of main industries.
Most types of industries are important as far as heavy metal pollution is concerned, but a
few, such as the fertilizer and basic steel works industries involve much more heavy metals
than the textile mill product or leather and finishing (Forstner-Wittman, 1981).
10
In general, effluents can be classified into groups based on physicochemical
similarities and on their effects on aquatic communities. Inert suspension resulting from
mining, quarry, and washing processes may impair ventilation and filter feeding rates or
decreases photosynthetic rates. Suspensions may also cause habitat modifications that in
turn can affect behaviours, or they may carry adsorbed toxic materials. Poisons, such as
acids, alkalis, heavy metals, phenols, cyanides, organic toxins, and radioactivity, typically
cause generalized depression of physiological rates and increased respiration.
Inorganic reducing agents, such as sulphides, sulphates and ferrous salts from
industrial effluents and mine runoff, may be directly toxic or may cause secondary effects,
such as lowered oxygen concentrations or pH changes. Organic effluents from sewage
treatment facilities, agricultural runoff, paper mills, and other sources may cause
enrichment and increase productivity. Severe organic loading may decrease productivity
through primary and secondary effects. Finally, some effluents, such as oil refinery wastes,
combine many of the above categories and produce wide variations in community response
to stress (Matthews et al., 1982).
11
TaEle . : Heavy metals employed in major industries (Forstner-Wittman, 1981)
EIIlXeQtV
Pulp,
papermills,
paperboard,
building paper.
Organic
chemicals,
petrochemicals.
&G
&r
&X
X
X
Fe
HJ
MQ
X
PE
X
Ni
SQ
X
=Q
X
X
X
X
X
X
X
X
Alkalis,
chlorine,
inorganic
chemicals.
X
X
X
X
X
X
X
Fertilizers.
X
X
X
X
X
Petroleum
refining.
X
X
X
X
X
X
X
X
X
X
X
X
Basic steel
works
foundries
Basic
nonferrous
metalworks,
foundries.
Motor vehicles,
aircraft plating
finishing.
Flat glass,
cement,
asbestos
product.
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Textile mill
product.
Leather
tanning,
finishing
Steam
generation
power plants
X
X
X
12
.3.
HeaY\ MetalV
Heavy metal pollution is a major environmental problem in the world. The term
‘heavy metal’ is somewhat imprecise, but includes most metals with an atomic number
greater than 20, but excludes alkali metals, alkaline earths, lanthanides and actinides. The
heavy metals are those metals that have a density greater than five, include about thirtyeight elements (Salgare, 1991). Apparently, studies on pollution of heavy metals in the
urban environment became prominent after the mid sixties, concurrent with enhanced
urbanization and industrialization processes worldwide. It was preceded with an earlier
shock of mercury poisoning associated with fishes consumed from the Minamata Bay,
Japan in the mid fifties (Kudo, 1992).
Meanwhile, in Malaysia, Johor and Penang states recorded the highest incidence of
mercury in their coastal waters (Department of Environment, 1994). Inorganic arsenic is
taken up rapidly by phytoplankton and this undoubtedly represents an important route for
the introduction of the element into aquatic food webs. Philips (1990) reported that total
arsenic concentrations of 14 to 42 Pg g –1 dry weight in three species of zooplankton from
offshore waters of the northeast Atlantic Ocean.
Of a large group of heavy metals (more than 40), the most toxic and widespread are
Hg, Cd, As, V, Cu, Sn, Zn, Sb, Mo, Co and Ni (Safronova et al., 1997). The metal
cadmium became a serious concern following the discovery that it competes with calcium
for sites in the human bone formation. Nevertheless, the toxicity of other metals such as
coppers, zinc, arsenic, cobalt and a few other minor elements became more prominent with
increasing interest for research in the field after the late sixties.
The natural or non-anthropogenic sources of heavy metals in the environment are
mainly geological in origin, being part of the earth formation components, through
weathering, erosion, leaching and other terrestrial processes, metals become parted from the
matrices of the earth to be incorporated with the various components of the soils’ masses, to
exist in geochemically unstable forms. From here, metals can find themselves in the various
environmental sinks. Mining activities are usually one of the major sources of metal
contamination in the environment. The main source of mercury, arsenic, zinc, copper and
chromium in river waters are from, urban and agricultural run-off, and effluent from
industries, sewage treatment plants, domestic discharges, constructions, earthworks and
13
pig farms (Department of Environment, 2002). Furthermore, the pollution of lead became
very much talked about, especially in the drinking water, urban air, food and drinks,
cosmetics and newly painted rooms. Concentrations of lead in vegetables from
Copengahen, Denmark were found to be 530 µg/kg due to the polluting activities around
the area (Petersen et al., 2002).
Heavy metals move in a rather intricate fashion within the hydrological cycles. An
interesting model shows that metals in the atmosphere (highly relevant in the urban
environment) will land up in the rainwater, and subsequently into the river water, the
estuarine water, seawater and back to the rainwater. Metals in the rain can also land up in
the soils and metals in the aquatic ecosystems can be found in the fluvial, estuarine and
oceanic sediments (M. Ahmad Badri, 1988). The flow chart in Figure 1.0 shows the
interrelated connections quite clearly.
.3.. ArVeQiF (AV): =
33
The ancient Greeks, who attributed a sex to metals, gave the name arsenikon (male)
to the natural sulphides of arsenic. The discovery of this element is sometimes credited to
Albertus Magnus in 1250. Arsenic has only one stable isotope, of mass 75. The boiling
point for Arsenic (sublime) is 613 0C. It is a Group VB element, which behaves as a
metalloid. Arsenic forms two series of oxygenated compounds: the arsenates [As (III)] and
the arsenates [As (V)] (Haissinsky and Adloff, 1965). Arsenic compound is principally
used in the pharmaceutical industry and in the preparation of insecticides and parasiticides.
14
SOIL
O&EANI&
SEDIMENT
SEA
:ATER
RAIN
ATMOSPHERE
RIVER
:ATER
FLUVIAL
SEDIMENT
FiJXre .0
ESTUARINE
:ATER
ESTUARINE
SEDIMENT
Movement of trace metals in hydrological cycle
Arsenic occurs widely in the earth’s crust. It is found in soils, many waters and
almost all plant and animal tissues. No one would take lightly the presence of this element
in food or drink. Yet, arsenic is almost universally distributed in plants and animals, and
daily intake, even in the absence of pollution, may be as high as 0.5 mg in all of us. The
principal use of arsenic is in the chemical industry and there it is widely employed in
pharmaceuticals, agricultural chemicals, preservatives and related compounds.
Unfortunately, arsenic is a persistent poison and, even after many years, some streams and
locations on farms remain toxic because they were once exposed to these chemicals.
Furthermore, the major uses of arsenic compounds currently are in agriculture and
forestry, much smaller amounts are used in the glass and ceramic industries, cloth and
semiconductor manufacturing, feed additives and drugs (Sittig, 1979). Compounds used as
pesticides are lead arsenate, copper acetoarsenite, sodium arsenate and organoarsenic
compounds. In addition to that, wood preservatives containing a mixture copper sulphate,
potassium dichromate and arsenic pentoxide are being used increasingly in treating piling
timbers and roof-trusses (Seiler et al., 1994). The preserved timber is resistant to both
fungal and insect attack.
15
In Malaysia, the presence of arsenopyrite and other arsenical ores in association
with tin, iron, gold, lead, copper and zinc ores have been reported in various mines both in
the Peninsula as well as in Sabah and Sarawak (Department of Environment, 1986a). Major
anthropogenic sources which release arsenic into the air, water and soil are ore smelters,
cement manufacturing, combustion of fossil fuels and extensive use of arsenical pesticides.
Some monitoring data obtained through Global Environmental Monitoring System (GEMS)
under the coordination of WHO shows the total arsenic concentration for Sg. Skudai is
0.005 mg/L (Department of Environment, 1986a). Besides that, from the studies in the Sg.
Langat basin, levels of arsenic have been reported to range between 0.003 to 0.049 mg/L
(Department of Environment, 1998). Accumulation of arsenic in herbs in Poland was found
to be 1.05 mg/kg (Lozak et al., 2001). In Nigeria, arsenic in crude oils was determined and
recorded levels ranged from <0.06 ppm to 0.166 ppm (Oluwole, 1992). Five species of
macro algae in South Australia were analysed and concentration of arsenic were determined
to be in levels ranged from 18-31 Pg g-1 (Maher and Clarke, 1984).
For the general population, ingestion through food and water forms the major route
of intake. Transplacental transfers of arsenic to foetal tissues, particularly the central
nervous system, have also been demonstrated and may pose a potential health threat in
early foetal development. Nevertheless, the in vivo toxic effects are essentially due to
enzyme inhibition by the formulation of arsenic-sulphur bonds between trivalent arsenic
and thiol groups (Lederer and Fensterheim, 1983).
The Food Act 1983 and Food Regulations 1985 in Malaysia allows less than
1 Pg g-1 of arsenic in food. Normally, acute poisoning by ingestion usually manifests first
as a feeling of throat constriction followed by difficulty in swallowing, epigastric
discomfort, violent abdominal pain with vomiting and diarrhoea, intense thirst, muscle
cramps, severe hypertension and collapse. Death may result from cardiac failure and is
preceded by restlessness, convulsion and coma. Furthermore, residual effects of acute
poisoning include peripheral neuropathy, cardiac and congestive heart failure, anaemia,
leucopoenia and skin lesions (Ndiokwere, 1985).
16
.3..2 &aGmiXm (&G): =
48
Unlike mercury and lead, Cd is not an ‘ancient’ metal, at least in terms of its use by
man. It is only in recent years that it has found widespread industrial application, mainly in
the metal plating and chemical industries. However, it is quite likely that it was unsuspected
used, and that humans experienced its highly toxic effects, for many centuries. Its presence
in zinc, for instance, is well known and in many instances in which ‘zinc poisoning’ was
believed to have occurred, it was probably cadmium that was the toxic agent. Even minute
amounts of cadmium are sufficient to cause poisoning. Moreover, since the metal is soluble
in organic acids, it easily enters acid foods with which it comes in contact. Cadmium is a
highly toxic element. It has been described as ‘one of the most dangerous trace elements in
the food and environment of man.
Cadmium is a divalent metal, homologous with zinc and mercury in the periodic
table. Cadmium is generated in waste streams from pigment works, textiles, electroplating
and chemical plants. Natural cadmium is a mixture of 8 isotopes with mass numbers
between 106 and 116, the most abundant being 112 Cd (24.07 %) and 114 Cd (28.86%). The
itai-itai disease in Japan was probably due to the transport of cadmium containing
particulates in water to the irrigation fields. Shellfish can accumulate cadmium from the
sediment and concentration of around 0.01 mg/L can retard the growth of aquatic plants
(Rao, 1991). Although, cadmium plating is the most important application of the element, it
is also used in fusible alloys, solders, stereotype plates, and bearings for automobiles,
photoelectric cells and alkaline accumulators (Forstner-Wittman, 1981).
Strohmeyer, who isolated the element and gave it this name to denote the
association of the two metals, recognized the presence of cadmium in zinc oxide in 1817.
The boiling point of cadmium is 765 0C. Only one, very rare, ore of cadmium is known,
namely genocide (sulphide), the metal is normally extracted from zinc ores. Concentration
of cadmium in coal is 0.01 to 65 mg kg-1 and more than 1 mg kg –1 in crude oil. In marine
sediments it was around 0.1 to 1 mg kg-1. Soil normally contains less than 0.5 mg kg-1
(Herber, 1994).
17
On the contrary, absorption through food is the most important route of cadmium
uptake for the general population. Acute ingestion of contaminated food and drink causes
nausea, vomiting, abdominal cramps, diarrhoea and shock. Chronic inhalation of cadmium
fumes produces effects on the kidneys causing renal tubular damage, lung emphysema as
well as anaemia, liver damage and later disturbances in calcium/phosphate metabolism. An
incident due to chronic ingestion that shows rise to renal tubular damage is the itai-itai
disease in Japan (Lepp, 1981a). In Malaysia, the death dose for cadmium poisoning is 10
mg (Food Act, 1983).
Under the WHO monitoring program, cadmium concentrations studied in Sg.
Skudai were found to be below detection limit (<0.001 mg/L) (Department of Environment,
1986a). Cadmium also induced changes in the histology of kidneys had been reported in
common carp, Cyprinus carpio (Cyprinidae) from the National Fish Seed Farm (NFSF)
Jyotisar, India (Singhal and Jain, 1997). Cadmium concentrations in Malaysian rivers
recorded levels ranged from 0.06 to 0.48 Pg g-1 (Universiti Kebangsaan MalaysiaDepartment of Environment, 2000). In Central Italy, cadmium was found to be in range of
0.24 Pg g-1 to 0.95 Pg g-1 in lichens collected from the environs of the town of Pistoia
(Loppi, et al., 1994).
.3..3 &hrRmiXm (&r): =
24
Chromium was discovered by Vauquelin in 1787 in a Siberian ore, and was isolated
in 1854 by Bunsen. Its name comes from colour, and refers to the varied tints of its
compound and ores. Chromium is a transition element of sub-group VIA, and it can assume
the oxidation states 0 (chromium hexacarbonyl) and I to VI. Apparently, chromium is
commonly used as a coating for the protection of alloys and metals, owing to its high
resistance to corrosive agents (electrolytic chromium plating). It is a constituent of
oxidation-resistant, refractory, very hard alloy. It is also a constituent of alloys for
electrodes and thermocouples (Hamilton and Wetterhahn, 1988).
18
Chromium is widely distributed in the earth’s crust, though concentrations are
generally relatively low, at about 0.04 per cent of the total solid matter: Its toxicity to
industrial workers has been recognized for many years.The most common industrial
sources are the alloy industry, wood treatment, and chromium mining operations. Besides
that, Cr is used extensively for manufacture as stainless steels, decorative and wearresistant surface treatments and manufacture of chemicals.
Furthermore, chromium salts are used in chemical analysis, tanning, dyeing,
ceramics, and in the dyestuffs industry. The major uses of chromium are in the
metallurgical industry for the production of stainless steel and other alloy steels, and in the
refractory. Other uses are in the electroplating, metal finishing and leather tanning
industries and in the production of fungicides, pigments, oxidants, and catalysts and in the
glass and photographic industries (Stoeppler, 1992). The usage of chromium and its
compounds is estimated almost 10-100 million tones per year (Mason and Moore, 1982).
Chromium is a mixture of 4 isotopes of masses 50, 52 (83.76%), 53 and 54. The boiling
point for chromium is 2672 0C (Herold and Fitzgerald, 1994).
Sediments from the Indus River Pakistan showed chromium concentrations from 3.2
to 23.5 Pg g-1 (Tariq et. al., 1996). Monitoring data from WHO shows that chromium
concentration in Sg. Skudai was found to be 0.001mg/L (Department of Environment,
1986a). Previous studies of chromium of Malaysian rivers recorded concentrations ranging
from 0.01 to 4 Pg/L (Universiti Kebangsaan Malaysia-Department of Environment, 2000).
Besides that, many plant species are adversely affected by chromium (VI) concentrations of
5 mg/L (Rao, 1991). Plants from urban areas of Punjab, Pakistan showed concentration of
Cr in range of 1.866ppm to 4.743 ppm (Iqbal and Qadin, 1989). Plants grown on serpentine
soils rarely contain chromium concentration larger than 100 mg/kg and Cr concentration in
excess of this value is due to soil contamination (Brookes, 1987).
Chromium can be carcinogenic and causes asthma and skin allergy Apparently, skin
ulcers result from local exposure to hexavalent chromium compounds, and present as
deeply penetrating ulcers over the fingers, hands and forearm. Dermatitis may either be due
to acute primary irritation, or allergic reactions. Other reported health effects include
cardiovascular damage, nephrotoxicity and liver necrosis (Herold and Fitzgerald, 1994).
The permissible level of chromium in food in Malaysia is 1.0 Pg g-1 (Food Act, 1983).
19
.3..4 &Rpper (&X): =
2
The use of copper dates back to the beginnings of civilization itself. The metal was
already used in the Badarian period, the earliest Egyptian civilization, 5000 years before
our era. It was known in Cyprus by the name of oes cyprium, which was changed to aes
curium and then to cuprum, whence the name of the element is derived. Copper is
malleable, ductile metal, and is an excellent conductor of heat and electricity.
Today, the primary use of copper, accounting for about half of the world production
is in the manufacture of electrical cables and equipment. It is still extensively used for
plumbing, though plastic piping has been taking over in recent years. Copper is still
occasionally used in sheets for roofing buildings, as well as for covering the hulls of boats.
A major use continues to be as a component of alloys, with zinc, tin, cadmium and other
metals. Copper salts have important pharmaceutical and agricultural uses.
However, anthropogenic sources of release of copper into the environment include
corrosion of brass and copper pipes by acidic waters, industrial effluents and fallout,
sewage treatment plant effluent and the use of copper compounds such as copper sulphate
as aquatic algaecides. Major industrial sources of copper include smelting and reining
industries, copper wire mills, coal burning industries and iron and steel producing
industries. Large quantities of copper can enter surface waters, particularly acidic mine
drainage waters, as a result of metallurgical processes and mining operations. Copper has
two stable isotopes of masses 63 (69.09 %) and 65 (30.81 %) respectively. The boiling
point of copper is 2567 oC.
Copper in herbs in Poland was found to be 1.00 mg/kg (Lozak et al., 2001). The
range of copper concentration found in sediments from the Chao Phraya River is 3.34 to
37.50 Pg g –1 and in water is (ND) non-detectable - 68.7 Pg g –1 ( Polprasert, 1982). On the
contrary, monitoring study conducted by WHO reported 0.008 mg/L of copper
concentration for Sg. Skudai river water (Department of Environment, 1986a). Meanwhile,
levels of copper in Malaysian rivers have been reported to range from 5.96 to 21.20 Pg/L,
(Department of Environment, 1998). Miryakova (1993) pointed out that the maximum
concentration of copper in gramineous pondweed is 23.5 Pg g –1. Acute gastrointestinal
symptoms may also result from ingestion of copper in contaminated food and beverages, or
copper salts in suicide attempts. Severe cases may produce fatal hepatic and renal damage.
20
Metal-fume fever, an influenza-like illness lasting about 24 hours, occurs after exposure to
0.1 mg/g of copper fumes or dust. Febrile reactions and haemolytic anaemia have also
occurred in patients due to absorption of copper from dialysis equipment (Stoeppler, 1992).
Copper poisoning had also been associated with brain damage. Furthermore, copper
ions form stable complexes, such as chelates with organic substances. Copper is an element
of Sub-group IB of the periodic table, and the most important valency states are II and I.
Apparently, most Cu2+ salts are soluble and coloured. The salts of Cu (I) and Cu (II) form
many complexes with mineral acids, ammonia, amines, pyridine, etc. The compounds of Cu
(II) are poisonous (Nriagu, 1979). Copper toxicity is also found in the livestock, notable
sheep and cattle. Livestock grazing in areas accommodating power lines had been shown to
result in increased Cu concentration in their milk, in comparison with the ones not
subjected to this exposure. These were attributes to Cu leaching from the power lines and
the subsequent grass uptake of the metal from the soils, and consequently the Cu found in
the milk (M. Ahmad Badri, 1988). The 1983 Food Act in Malaysia allows 30 mg kg-1 of
copper in food.
.3..5 LeaG (PE): =
82
Lead has been known since ancient times. Lead belongs to the fourth column of the
periodic table (Group IVB); its maximum valency is therefore IV, but II is far more stable.
The divalent plumbous salts exhibit certain similarities to the alkaline earth salts.
Tetravalent lead forms few compounds, though mention should be made of PbO2, the alkali
plumbates, PbCl4, and Pb (SO4) 2, which are very powerful oxidizing agents. Often, it is one
of the most widely used metals in industry: in piping, conducting materials, accumulators,
lead chambers, printing characters, soldering, anti-knock substances and coloured pigments
(Tscuchiya and Kenzaburo, 1979). In storage battery industry, lead - antimony alloys is
used as grids and lugs; litharge (PbO), red lead (Pb3O4) and grey lead (PbO2) as active
material pasted on the plates. Red lead and yellow lead chromate are used as pigments in
paints (Haissinsky and Adolff, 1965).
21
However, there is no doubt that lead is seriously toxic to human beings and
evidence is accumulating that considerable differing effects result in different human beings
who have absorbed similar amounts. Bowen (1966) explained that lead is not essential as a
trace metal to nutrition in animals, but is a cumulative poison. In natural form, lead
comprises 4 isotopes with mass numbers of 204 (1.48 %), 206 (23.6 %), 207 (22.6 %) and
208 (53.3 %). Boiling point for lead is 1749 oC. It would seem that absorption through food
and drink is the main pathway for adults, though estimates of the percentage intake (and
absorption) through this route compared with inhalation differ quite widely (Hester, 1983).
Previous studies of the Sg. Semenyih showed levels of lead ranging from 0.1 to 1.76
Pg L–1 (Department of Environment, 2002). Lead poisoning in children was also traced to
the consumption of lettuces containing high levels of the element. The sources of Pb were
found to be old lead batteries that had been dumped on the ground within the
neighbourhood of vegetable plots (Lepp, 1981b). NAS (1976) reported that grass was
contaminated by lead within 152 m downwind of roads in Colorado, USA. It was also
reported that lead in soils ranged from 128-700 Pg g –1. Whereas, the monitoring study
conducted by WHO found that the concentration of lead in the Sg. Skudai river water was
0.8 mg/L (Department of Environment, 1986a). In Poland, herbs were found containing
0.94 mg kg –1 of lead (Lozak et al., 2001).
Nevertheless, lead has detrimental effects on the human body and its functions,
affecting the metabolism, blood and kidneys. Furthermore, lead is also known to
accumulate in the body more rapidly than it is excreted. Lead is known to retard
haemoglobin production, the cause of anaemia. Other effects are damages to the nervous
systems, the kidneys and the brain. Lead is also known to cause precipitation of protein,
through the interaction of lead ions with the sulphydryl (-SH) groups of proteins. Studies on
human skeletons prove that lead tends to be accumulated in bones, and its excretion out of
the human body is rather slow (Seiler et al., 1994). Maximum lead levels allowed in fish for
consumption in Malaysia is 2 Pg g –1(Food Act, 1983).
22
.3..6 MerFXr\ (HJ): =
80
Mercury was known to the ancient Chinese and Hindus, and has been found in
Egyptian tombs dating from 1500 B.C. The element owes its name to the planet Mercury;
the symbol is derived from the latin hydrargyrum, liquid silver. In the middle ages the
element was called argentums vivum. Mercury is a mixture of 7 isotopes with atomic
number between 196 and 204, the most abundant being 202 Hg (29.80 %). The tendency to
form covalent bonds is found in a considerable number of compounds of Hg with S, N, and
C. The organometallic derivatives of mercury are remarkably stable. Mercurial compounds
are insoluble, with the exception of the nitrate, chlorate, and perchlorate. However, mercury
is very slightly soluble in water (0.3 µ mol/L) and organic solvents; it dissolves many
metals at normal temperatures, particularly Pb, Zn, Ga, Cd, Tl. In, and the alkali and
alkaline earth metals, forming amalgams, which may be simple solid solutions or
intermetallic compounds; these alloys are used in analysis and in industry (Watson, 1979).
Today, Hg is valued and widely used in industry, mainly because of its chemical
properties. It is used as a catalyst in a variety of industrial and laboratory reactions, some of
great economic value. Its physical property of high conductivity makes the liquid metal
valuable in the electrical industry. Of particular significance in recent years have been the
serious instances of poisoning, especially by organic mercury, through industrial pollution.
Mercury can still be considered among the most dangerous of all the metals we are likely to
meet in our food. Man’s industrial activities, including the combustion of fossil fuels, also
contribute to the environmental mercury burden.
Mercury and its compounds play an important part in electrochemistry. The metal
itself is used as a coolant in certain types of reactors, in the metallurgy of gold and silver, as
a catalyst in organic chemistry, and in the manufacture of lamps, relays, and switches. Both
mercury and its compounds are highly toxic. Out of the 10 000 tones of mercury produced
worldwide yearly, it has been estimated that 25 % is consumed by the chlor-alkali industry,
20 % in electric equipment, 15 % in paints, 10 % in control and measurement system, 5 %
in agriculture, 3 % in dental practice, 2 % in laboratory and 20 % in others which include
detonators, catalysts, preservatives and cosmetics (Palmer, 1995). Nevertheless, major uses
in Malaysia also cover the above-mentioned areas including chlor-alkali industry, electrical
equipment, paints and dental practice. In a recent survey of a wide range of paint products
23
available in local market, 12 out of 16 brands of emulsion paints were found to contain
mercury ranging from 0.005 % to 0.066 %, while 5 out of 7 brands of gloss pints (solvent
based) range from 0.003 to 0.037 % (Department of Environment, 1985).
Apparently, a monitoring study found 0.1 mg/L concentration of Hg in the Sg.
Skudai (Department of Environment, 1986b). Meanwhile in the Sg. Langat , mercury level
is reported to be 0 to 0.004 mg/L (Law and Singh, 1986). Because of the toxic nature of
mercury, the Malaysian government established a limit for public water supplies of 0.002
mg/L of mercury. The average concentrations for aquatic plants, benthic invertebrates and
fish in the Ottawa River were 14.2 ppb, 233 ppb and 162 ppb, respectively, for total
mercury (Kudo, 1992). In Canada, Stokes and Dreier (1983) reported that concentration of
mercury in water were (10 - 30 ng/ L) and sediment concentrations were quite variable
from 36 to 150 ng/g. Polprasert (1982) reported that mercury levels in aquatic plant from
the Chao Phraya river estuary ranged from 0.75 to 1.26 ppm in leaves and 0.28 to 0.68 ppm
in floating stems.
On the contrary, the earliest cases of methyl mercury poisoning were described, as
neurological features were predominant, presenting as paraesthesia, constriction of visual
field, dysarthria, ataxia and astereognosis after an asymptomatic period of 3 to 4 months
from exposure. The syndrome as in Minamata, resulting from consumption of fish
contaminated by methyl mercury, and later in Niigata (Sakai et al., 1986). Other reports
clinical effects due to methyl mercury include dermatitis, exfoliative dermatitis and
cardiovascular damage. Moreover, intrauterine exposure to mercury has been reported to
cause psychomotor retardation, severe brain damage resulting blindness and hypotoniea,
and learning difficulties with poor intelligence test performances (Hans et al., 1994).
Several cases of wildlife poisoning from seeds treated with methyl mercury were
documented in Sweden during the period 1948 - 1965 (Lindquist et al., 1984).
24
.3.. NiFkel (Ni): =
28
Cronstedt discovered nickel in 1751; its name is derived from the Swedish
kopparnickel (goblin copper). Nickel possesses 5 isotopes with mass numbers 58 (67.88
%), 60 to 62, and 64. Its principal valency is II, but compounds corresponding to the
oxidation states of 0, III, IV, and I are also known. The boiling point of nickel is 2732 oC.
Nickel is a hard, malleable, ductile metal, crystallizing in the face-centred cubic system.
The metal is produced by roasting the sulphide ores and reducing the oxide with carbon; it
is purified by electrolysis (Adriano, 1986).
The main uses of nickel are in the manufacturing of stainless steels and high nickel
alloys (about 40 % of total Ni produced). Nickel also enters into the composition of
numerous alloys: 36 % Ni-steel or Invar has a coefficient of expansion which is almost
zero; alloys with high resistivity (constantan, manganin, nichrome) are used as resistances
and for the manufacture of thermocouples; the 68 % Ni-alloy (3 % Cu, 2 % Fe) Monel has
high chemical resistance. Nickel is used as a protective coating by electrolytic deposition
(nickel plating). Nickel has been shown to be essential for the growth of some
microorganisms. The growth of blue-green algae Oscillataria spp and of the bacterium
Alcalegenes eutrophus has been shown to depend on the presence of nickel in specially
purified media (Eisler, 1981).
However, other major contributors of Ni are the miners, smelters, and refiners,
casting of alloys, and electroplating industries, and in nickel-plating (about 20 % of Ni
produced). Nickel is found in coins, household materials and food-processing equipment.
Other uses of nickel include nickel-cadmium batteries (nickel hydroxide), electronic
components (nickel carbonate), and catalyst in industrial and oil refining and in certain
fungicides. Nickel is also present in many domestic cleaning products.
In man, the health effects of nickel compounds are predominantly on the skin and
respiratory system. Some of these effects are hypersensitive in nature, including bronchial
asthma and contact dermatitis. Allergic skin reactions from nickel are very common among
the general population as well as exposed workers, and may result in chronic changes such
as lichenification. Nickel also has acute inflammatory effects on the nasal membrane
(Reilly, 1991). Ure and Berrow (1982) in a recent survey from the world literature quoted
93 mg/kg for nickel in soils. The concentration of nickel in the Sg. Skudai was found to be
25
0 - 10mg/L (Department of Environment, 1986b). Nickel concentration found in the Sg.
Langat basin ranged from 16.42 to 31.83 ppb (Universiti Kebangsaan Malaysia –
Department of Environment, 2000). A study conducted in Vietnam found that the
concentration of nickel in the Imperata cylindrica grasses is 0.79 ppm (Tran Van and
Teherani, 1989a). They also reported that the concentration of nickel in the Dalat lake
sediment in Vietnam is 3.68 ppm (Tran Van and Teherani, 1989b). Lozak et al. (2001)
reported that nickels in herbs in Poland were found to be 1.00 mg/kg.
.3..8 =iQF (=Q): =
30
Zinc has been known for a very long time; it was used in alloys since the 7th century
in India, and in the 11th century in China. Marggraf isolated the metal, in 1776. The element
is essentially divalent. Despite that, several zinc compounds are covalent: the sulphide,
selenide, telluride, and oxide, as well as the organozincs, which were the first
organometallic derivatives known. Apparently, zinc is prepared by the reduction of ZnO
with carbon monoxide, or by electrolysis of a salt, and purified by fractional distillation. It
is used in galvanizing iron or steel, and enters into the composition of important alloys:
brasses, nickel silver and mouldable alloys. Zinc is a mixture of 5 isotopes with mass
numbers of 64 (48.89 %), 66 - 68, and 70. Boiling point for Zinc is 907 oC (Seiler et al.,
1994).
Zinc is also an important element in batteries and accumulators. Moreover, zinc
chloride is used as a desiccant, in the conservation of wood, and in the manufacture of
batteries. Meanwhile, ZnS finds an important application as pigment and zinc peroxide, is
used as an antiseptic. The principle minerals of zinc are the sulphides (blende or sphalerite),
carbonates (smithsonite), and silicates (calamine). Zinc also plays an important part in the
human organism, and is also indispensable to the nutrition and growth of plants. The
maximum level of zinc allowed in fish and fish product is 100 Pg g –1(Food Act, 1983).
26
Zinc is used mainly in the production of non-corrosive alloys, brass and in
galvanizing steel and iron products. Galvanized products that appear widely include
automobile parts and household appliances. Zinc undergoes oxidation on the surface of the
galvanized product and this protects the enclosed metal from degradation. About 33 % of
the world production of zinc is used in galvanizing (hot-dip and electro galvanising),
spraying, painting and sheradising; 25 % in the production of alloys for die-casting; 20 % in
the production of brass and the reminder in the production of zinc oxides, zinc sheets for
batteries etc. Zinc oxide, which accounts for the largest quantities of zinc compounds, is
used in rubber and as a white pigment. While, zinc sulphate is therapeutic and is used in the
treatment of zinc deficiency in humans (Jackson and Jackson, 1996).
The carbonates (organic zinc compounds) are used as pesticides. Inhalation of zinc
chloride fumes may produce acute pneumonitis and fatal pulmonary edema, occasionally
resulting in pulmonary fibrosis. Consequently, ingestion of zinc may also produce
symptoms of food poisoning such as nausea, vomiting, diarrhoea and abdominal pain.
Metal fume fever, an influenza-like illness with headache, fever, sweating, chest pain and
leucocytosis is caused by inhalation of zinc oxide fumes. The illness lasts for 6- 48 hours,
coming on within a few hours after exposure, and is never fatal (Solomons and Cousins,
1984).
Besides that, a study on plants, lichens (Parmelia caperata) in Central Italy
recorded 74.12 Pg g –1 of zinc (Loppi et al., 1994). Bowen (1966) reported 100 Pg g –1 of
zinc in plants. A study of grass (Imperata cylindrical) plant (Mimosa pudica) and rice in
Vietnam showed 7.58 ppm, 19.46 ppm and 17.01 ppm concentrations of zinc respectively
(Tran Van and Teherani, 1989a). Previous studies of zinc in Malaysian rivers such as Sg.
Gombak , Sg. Kelang , Sg. Semenyih and Sg. Selangor recorded zinc concentrations
ranging from 0.27 to 38.33 Pg L –1 (Universiti Kebangsaan Malaysia, 1996). Meanwhile,
concentrations of zinc along the Sado River, Portugal recorded levels ranging from 110 to
1800 Pg L –1. (Monteiro et al., 1995). Sakai et al. (1986) reported that sediments from the
Toyohira River, Japan recorded 152 Pg g –1 of zinc.
27
.4
ATXatiF EFRV\Vtem
Water covers about three quarters of the earth’s surface, almost all as oceans.
Virtually all surface waters contain life in one form or another; hence, aquatic ecosystems
would be important for their sheer volume, if for nothing else. In addition, aquatic
ecosystems are simpler in many ways than terrestrial systems, since the omnipresent factor
that sets the tone for all aquatic ecosystems, regardless of their biotic complexity, is water.
It is the medium within which all aspects of the ecosystem coexist, both living and
nonliving. It is the source of all nutrients for aquatic life, including the gaseous nutrients
such as oxygen and carbon dioxide. It is the medium by which organic and inorganic
wastes and sediments are distributed throughout the ecosystem (Karr, 1995).
There are a number of reasons why biological studies are important. Drinking water,
eating fish, and using aquatic ecosystems as recreational resources of course, also link man
to the freshwater community. We can consider the effects of pollutants we record on the
biological community as an early warning system for potential effects on ourselves.
Biological communities may also respond to unsuspected or new pollutants in the
environment. Finally, some chemicals are accumulated in the bodies of certain organisms,
concentrations within them reflecting environmental pollution levels over time. In any
particular sample of water, the concentration of a pollutant may be too low to be detectable
using routine methods, but nevertheless will be gradually accumulated within the
ecosystem to concentrations of considerable concern in some species (Harrison, 1996).
The natural world is organized into interrelated units called ecosystems. An
ecosystem is a region in which the organisms and the physical environment form an
interacting unit. Weather affects plants, plants use minerals in the soil, and affect animals,
animals spread plant seeds, plants secure the soil, and plants evaporate water, which affects
weather. There are many kinds of aquatic ecosystems, but the most meaningful breakdown
is based on the salinity, or amount of material dissolved in the water. Most of the earth’s
surface water (99.99 %) is in the oceans, which contain about 35 parts per thousand (%0)
dissolved salts. Of the remainder, most is fresh water with a salt content under 1/5 (%0)
found in both lakes and ponds (still water) or in rivers and streams (running water). The
most common transition zone between a river and the sea is the estuary, which has a
dissolved solid content intermediate between those of fresh and marine waters. Water
bodies such as ponds, lakes, estuaries, and rivers may be viewed as ecosystems. Each of
28
these ecosystems contains different individuals, species, populations, and communities,
which occupy their own niche in the system. They interact with each other in many ways,
including through the control of the food chain, birth and death rates, and the provision of
suitable living spaces (Greenberg et al., 1979).
However, to determine that an environmental change is going to result in pollution
requires a careful study of ecosystems. An ecosystem is simply how living things relate to
their environment. A study of fresh water ecology is an ideal way to introduce the
ecosystem concept. The biotic components consist of plants, animals and protists. The
abiotic components consist of soil, water, all and such physical factors as light, wind, and
temperature (Hall and Morrison, 1978). Anyway, when monitoring background levels and
more specific pollution on land or in the sediments of a water body, measurements will
often be made of levels in the plants or organisms that the soil or sediments support. In
many cases flora or fauna provide excellent indicators of the degree of pollution as they
may act as bio concentrators (for example of heavy metals from suspended material in
shellfish). The simultaneous measurements of pollutant levels in soils and plants as well as
in water, sediments, and aquatic biota are therefore often carried out (Seaborg, 1980).
Metal contamination of aquatic organisms may be employed in monitoring for three
main purposes. First, is for the protection of human health and for organisms harvested as
food. The identification of potentially unknown areas of elevated contamination and local
to individual discharges, there is the need to assess the extent of the zone of contamination.
Temporal change is to be monitored to identify the trend of contamination, especially near
effluents, in order to identify stability, improvement or more importantly deterioration.
Biological monitoring must also take into account the vast diversity of effluents and
receiving waters as well as the possibility that a number of different types of effluents may
enter the system. Five ways pollution may harm aquatic life in a river:
1.
Reduction in oxygen levels may occur through biotic or abiotic oxidations
of reduced compounds.
2.
The chemical or its breakdown product may be toxic.
3.
Temperature shocks and fluctuations may be harmful in that they affect
critical physiological processes.
4.
Physical properties of the effluents may result in abrasion and smothering
by sedimentation.
29
5.
Habitat alteration may result from increased turbidity, sedimentation, or
other such effects (Matthews et al., 1982).
Meanwhile, the materials discharged to the rivers and streams flow via larger rivers
and lakes to the oceans. On the way they may become incorporated into the sediment.
Alternatively they may be metabolised by the plant and animal life in the water and thus
enter into their food chain. Hence, wherever in the environment the samples are collected,
they represent the same process of pollution although occurring in different time spans.
Furthermore, soil, vegetation, sediment, lake water samples, etc., can give a measure of the
pollutants released over a longer time period, often representing in fact an integration of the
pollution that has occurred over previous months or years. For example, mercury
contamination of fish and mussels in the Derwent Estuary of Tasmania observed similar
tissue concentrations of 2.0 ppm wet weight (Goulden, 1978).
Apparently, ecosystem pollutant pathways provide the route between pollutants
stored in environmental sinks and pollutants found in biological organisms. At the
ecosystem level, exposure is assessed in terms of species of organism or entire trophic
levels. In general, exposure is related to the trophic status or organisms, with the greatest
exposure experienced by biota occupying the highest trophic positions. The transfer of
pollutants through ecosystems is usually described within a series of compartments, each
representing one stage in a known food chain. It is at the single organism level that the
effects of a given exposure are most easily detected, and most widely studied (Yusof
Samiullah, 1988).
30
.4.
ATXatiF PlaQt
The increasing pollution of rivers connected with disposal of wastes originating in
industrial emissions and in industrial, agricultural and household uses of water is well
known. Experts estimate that wastewater fed directly into water bodies may introduce as
many as a million different pollutants into our aquatic ecosystems. Moreover, major factors
for sensitivity of aquatic ecosystems to pollution, besides role of these systems as receiving
bodies for effluents, may be related with structure of food chain. Subject of heavy metals
pollution of different aquatic environments has received the much-needed attention
recently. Also, recent studies have shifted emphasis towards impacts on metabolism of
aquatic organisms and their ability to accumulate both essential and non-essential metals.
Impacts caused in an aquatic system may depend on the toxicant distribution within the
three compartments: water, suspended matter and sediment (Wollast, 1982).
Nevertheless, the fates of pollutants in the biosphere have received much attention
during past decades. The cycling of heavy metals, radioactive wastes, and atmospheric
pollutants has been studied in terrestrial and marine systems (Hester, 1983). Moreover,
living organisms have influenced the steady state levels of elements in the atmosphere, in
freshwater systems, in the soil, and in the oceans through geological time. Inorganic and
organometallic compounds have been synthesized, changed, and decomposed through
biological activities for five billion years. An important link in the transfer of trace elements
from soil to man is plants. Element content of essential elements in plants is conditional, the
content being affected by the geochemical characteristics of a soil and by the ability of
plants to selectively accumulate some of these elements. Bioavailability of the elements
depends on the form of their bond with the constituents of a soil. Plants readily assimilate
through the roots such compounds, which dissolve in waters and occur in ionic forms.
Additional sources of these elements for plants are: rainfall; atmospheric dusts; plant
protection agents; and fertilizers, which could be adsorbed through the leaf blades (Lozak et
al., 2001).
31
The advantages of using plants, as indicators are summarized below:
(1)
Vegetation samples are more practicable to collect than soil because they
weigh less.
(2)
In thick (dense) vegetation, plant sampling is quicker.
(3)
Large plants exploit the equivalent of many kilograms of soil and hence
can be more representative.
(4)
Deep-rooted plants can reveal mineralised areas not accessible by surface
sampling of soil.
(5)
Chemical analysis of plant tissues is less complicated and quicker than
soil analysis.
(6)
Where the plant accumulates an element, this can produce a more
sensitive method of detection than soil sampling.
In this study, an aquatic plant was selected according to its availability along the Sg.
Skudai river system. The local name of this plant is rumput gedabong (malay), it is a
common reed and its scientific name is Phragmites karka. This plant belongs to the
Gramineae (Poaceae) family and other synonyms for it are P. communis, P.filiformis and P.
roxburghii (Lim et al., 1998). A brief description of this plant is it is perennial, gregarious
plant up to 4 m tall, erect, with creeping stolons up to 20 m long. Stems hollow, many
nodded, up to 1.5 cm wide. Its leaves are about 20 – 60 cm long by 8 - 30 mm wide,
alternate. The plants has inflorescence of about 20 - 70 cm long on drooping panicles,
dense, with many fine branches, brownish when young but turning silver on maturity. It can
be propagated by seed and stem cuttings. The inflorescence is normally a feathery panicle
up to 75 cm long, often purplish. Lower florets usually sterile or male and upper florets are
bisexual (Cook, 1990). An illustration of this plant had been described by Ahmad Azly
(1988) as in Figure. 1.1. The common habitat for this plant is in moist and water logged
areas, both fresh water and brackish, along rivers, ditches, lake shores, ponds, lakes and
abandoned tin mining areas. Its distribution is widespread throughout Malaysia and also can
be found in other countries such as India, Sri Lanka, Myanmar, Thailand, Indonesia and
Australia (Kress et al., 2003). Figure 1.2 and 1.3 show the pictures of the plant sample that
was collected all through the nine months of sampling for the Sg. Skudai river system.
32
Only during the past 200 years have industrial activities dramatically changed the
distribution of the elements at the surface of the earth. Organisms have been and are
adapting to these changes. Furthermore, monitoring studies of heavy metals had also
included most types of aquatic organisms, including phytoplankton. The use of plants had
been quite extensive and they are generally accepted as good and effective indicators of
heavy metal pollution. Various parts of the plants had been studied including the leaves,
bark, roots, and rhizomes of grasses, fruits and flowers (Iqbal and Qadin, 1989). Among
numerous representatives of the biological world, the higher aquatic plants have their
advantages, as they represent a convenient object for observations, are nonmigratory and
are capable of uptaking and accumulating substances of different chemical nature (Gulati,
1987). These properties were used to investigate the pollution of different parts of the river.
Figure 1.1
An illustration of Phragmites karka (Ahmad Azly, 1988)
33
FiJXre .2
FiJXre .3
Phragmites karka growing naturally by the river bank
Close-up of inflorenscence of Phragmites karka
34
However, plant life is abundant in a slow-water ecosystem. It includes rooted
vascular plants such as pondweeds and grasses, firmly attached aquatic mosses, and large
multicellular filamentous algae. Very small floating plants such as duckweed may cover
much of the surface of the slowly moving stream, especially in its slowest backwaters.
Apparently, from these multiple representatives of higher aquatic vegetation, basically
submersed types of plants, was chosen in this study. For higher aquatic vegetation, water
and bed material are the sources of mineral nutrition. Many heavy metals in natural waters
are microelement, and in small quantities (10-3 to 10-5 %), they enter into the composition
of cells and play an important role in the process of metabolism of aquatic organisms.
Depending on the conditions of their habitats, plants may accumulate heavy metals in
quantities considerably exceeding their content in the habitat (Miryakova, 1996).
Furthermore, the environmental effects resulting from the bioaccumulation and evidence
that a persistent material may be present in an effluent necessitates assessment of its rate
and degree of uptake by aquatic organisms exposed to low levels of the chemical, with
analysis of organs and tissues (Wollast, 1982).
.4.2
SeGimeQt
Among the abiotic sinks, the more easily sampled, analysed and determined are
water, soils and sediments. Sediment samples became increasingly popular as the media for
heavy metal analyses. Sediment samples are not only used to monitor heavy metals
pollution in natural waters but also within the framework of international cooperation in
ocean and coastal waters. It may represent the largest reservoir for heavy metals within an
aquatic system, and it is also particularly useful in detecting pollution sources and in the
selection of critical sites for routine water sampling (Forstner and Wittmann, 1981). This is
important in monitoring works in both water and the sediments.
Bottom sediments represent an important indicator of contamination because they
tend to accumulate pollutants in aquatic systems. They therefore help identify areas, which
have become contaminated and reveal spread patterns from sources and contaminant input
history. They show much less temporal and spatial variation than the water column and thus
provide more reliable time integrated information than water column data. In addition,
metal levels in sediments are generally one to two orders of magnitude higher than the
amount of dissolved forms in water (Beckett et al., 1991).
35
Furthermore, sediment analyses may also provide a quantitative approximation of
the metal concentrations of associated waters. It is also important for assessing the relative
importance of the sediments as a source of metals to the aquatic organisms as well as to
determine what fraction of the sediment - sorbed metals is “bioavailable”. Generally, the
solid matrices are popular for heavy metals pollution and monitoring studies due to the
easier operational procedures in terms of sampling, laboratory analyses and storage. They
are also often accepted as the final recipient of metals of pollution origin from the air,
water, soil and the degradation of biota (Sakino et al., 1980).
Apparently, sediments are broken up rock fragments that may or may not be
chemically altered by weathering. In many ways, sediments are intermediate between rocks
and soils, overlapping in certain characteristics with each. Just as rock particles are worn
away by wind and water, sediments are deposited when the erosive- transportive force is no
longer sufficiently powerful to erode or transport materials. Depositional areas can be any
place where the velocity of the transportive medium decreases, such as flood plains along
rivers, in lakes, or in the sea. The oceans are the ultimate depositional sites for all
sediments. In spite of that, sediments interact most strongly with living organisms in
aquatic ecosystems. They are the bottom of lakes and oceans, as well as of streams that do
not flow directly over bedrock. Nutrients collect in the sediments, and many aquatic
ecosystems depend to a large extent on the cycling of nutrients back and forth between the
sediment and the water. Sediments are also the rooting medium for aquatic plants and home
for burrowing animals (Dixit and Witcomb, 1983).
36
.4.3
HeaY\ Metal &\Fle iQ ATXatiF EFRV\Vtem
Most of the pollutants enter the environment as emissions to the atmosphere or as
discharges to water bodies. These may be either in concentrated point sources, such as from
factory smoke stacks and sewage discharges, or in a diffuse form such as from automobiles
exhaust and run-off from agricultural land (Goulden, 1978). Due to the multiplicity and the
cumulative effects the actual toxicity of a particular metal is not often easily observed in
normal situations, with the exceptions of incidences such as the Minamata or itai-itai cases.
Moreover, heavy metals of pollution origin may exist in various forms of the environmental
solid and non-solid media, which can be referred to as the abiotic sinks (such as sediments,
soils dusts, water) and the biotic sinks (such as plants, livestock, fish and other aquatic life,
earthworms, and including human.
Nevertheless, several metals are present in rivers and lakes as a result of domestic
and industrial human activities. Heavy metals are not biodegradable and enter into the food
chain by a number of pathways. The accumulations of Cr, Cu, Zn and other elements in the
aquatic environment raise the risk of toxic concentrations of these elements that interfere
with a number of life processes (Veado et al., 1997). Furthermore, the urban environment,
the location of which is usually in association with an aquatic ecosystem (lake, rover,
estuary and seaside) can be shown to have a rather interesting heavy metal cycle. One such
schematic presentation can be seen in Figure 1.4. It can be observed that man can be
exposed to pollution of heavy metals directly from the biota e.g. fish, surface water, ground
water or vegetation.
The metals in the aquatic biota are in constant interaction with the metals in the
surface water, suspended matter, sediment and the interstitial water (water within sediment
columns). The ground water used by municipalities in various parts of the world may
actually be in constant equilibrium with soils, surface water and the interstitial water. These
interactions show that metals can move quite freely once they are deposited in any one of
the environmental ecosystems or media (Harrison, 1996).
37
Consequently, tidal waters and the sea do not have unlimited capacity to assimilate
all constituents of liquid effluents without some risk to their ecological systems. However,
these environments can continue to be a useful facility for disposal of industrial liquid
wastes, provided that a decision to proceed with discharge has been based on an ordered
and controlled approach. This must involve investigative and engineering techniques
appropriate to the particular circumstances on the site where the effluent is produced and to
the nature of the receiving water. A small number of well-publicized adverse ecological
effects, caused by persistent chemicals and major oil spill, have given rise to public concern
about pollution of the aquatic environment. In turn, this has resulted in proliferation of
legislation aimed at limiting the levels of chemicals in the environment. Establishing
controls and monitoring to ensure compliance presents problems to the administrator, the
controlling authority and the discharger (Hester, 1983).
A4UATI&
STUDIES
SUSPENDED
:ATER
MAN
SURFA&E
:ATER
VEGETATION
GROUND
:ATER
SOIL
BIOTA
TERRESTRIAL
SEDIMENT
INTERSTITIAL
STUDIES
:ATER
FiJXre .4
Schematic presentation of metal reservoirs and their interactions in aquatic and
terrestrial systems, (M. Ahmad Badri, 1988).
38
.5
ReVearFh OEMeFtiYeV
River pollution is not a recent problem. The pollution of rivers really began at the
time of the industrial revolution, in the early nineteenth century. Hence, contamination by
hundreds of pollutants through industrial discharges into the river is one of the major causes
of environmental problems in our river system. This is due to the industrial activities
occurring along or close to the rivers. Releases of chemicals to the water and soils may
degrade environmental quality and result in the destruction of ecosystems and their flora or
fauna, bioaccumulation of chemicals in food chains, and or short- or long- term human
health effects in the exposed population. It is therefore, imperative to determine the impacts
of river system pollution on the aquatic ecosystem due to industrial pollutants in rivers of
Malaysia.
The research objectives can be outlined as follows:
z To
determine the river water quality using a number of parameters and to compare it
with the Malaysian Water Quality Guidelines.
z To
produce data of heavy metal concentration levels in water, plant and sediment
samples from Sg. Skudai using nuclear and spectrometric analytical techniques.
z To
carry out correlation studies on the uptake of heavy metals in the water, plant
and sediment samples from the river.
z To
determine the uptake and accumulation of heavy metals by a plant species from
the river.
39
.6
SFRpe RI ReVearFh
Ɣ
To analyze the river water quality for pH, DO, T, BOD and COD and to compare it
with the Interim National Water Quality Standard (INWQS) for Malaysia.
Ɣ
To analyze the concentration level of heavy metals such as Hg, As, Pb, Cu, Cd, Cr,
Zn and Ni in water, plants and sediment samples using NAA and ICP-MS
techniques.
Ɣ
To compare the result of elemental concentration in this study with the
recommended level by the Interim National Water Quality Standard (INWQS) for
Malaysia and the DOE Water Quality Criteria for protection of aquatic life
Ɣ
To conduct correlation studies on the uptake of heavy metals such as Hg, As, Pb,
Cu, Cd, Cr, Zn and Ni in river water, plants and sediment samples.
Ɣ
To observe the trend of heavy metal pollution based on uptake and accumulation of
a plant species.
&HAPTER 2
ANALYTI&AL METHODS
2.0
IQtrRGXFtiRQ
In recent years great advances have been made in analytical methodology, for
e[ample, it is noZ possible to determine levels of the metallic elements at fractions of a part
per 1 9 (parts per billion). Several methods have been used to measure the environment
pollution in Zater, sediments and aTuatic plants. Instrument neutron activation analysis
(INAA) is a classic method for multi-elemental determinations, Zhich has a high sensitivity
at trace level (Hester, 193).
Inductive coupled plasma-mass spectrometry (ICP-MS) may also be used for trace
analysis of environmental samples. The ICP-MS multi-elemental techniTue is accurate,
sensitive and fast, alloZing a daily processing rate of up to 1 samples or more and has
recently been used to determine the composition of river Zater and for routine trace
analysis. ICP-MS has become one of the preferred methods of elemental analysis Zith
detection limits for most elements less than .1 ȝg/L (Parry, 1991).
2.
IQGXFtiYel\ &RXpleG PlaVma ± MaVV SpeFtrRmetr\
Multielemental inorganic mass spectrometry has a long and distinguished history as
the method of choice in the laboratory for ultra-trace levels, being particularly valued for its
high degree of elemental specificity and very loZ and relatively uniform detection limits. Its
application has, hoZever, alZays been restricted by the high cost of instruments, the high
level of skill needed for operation and data interpretation and a relatively loZ rate of sample
throughput.
41
2..
The OriJiQV, Reali]atiRQ aQG PerIRrmaQFe RI I&PMS S\VtemV
Inductively coupled plasma-mass spectrometry (ICP-MS) is a relatively neZ
instrumental techniTue for trace element analysis. The concept of interfacing an ICP Zith a
Tuadrupole mass filter emerged in the early 197s and Zith the rapid development of
instrumentation the first commercial instruments became available in 193. Since then the
techniTue has gained Zide acceptance as a versatile analytical tool for trace and ultra trace
multi element analysis (Gray, 199).
There are many features Zhich make ICP-MS an attractive techniTue for environmental
trace-element studies. ICP-MS provides:
(i)
Good multielement capability for determining a large number of elemental
concentrations over the range of ȝg g-1 to sub-ng g-1 , especially in the presence
of major environmental matri[ components, such as Na, Cl, S, P, and Si.
(ii)
Enhanced sensitivity for undertaking ultra trace element determinations Zith
detection limits in aTueous solution generally beloZ .1 ng mL-1. Such loZ
detection limits are desirable for evaluating Zater Tuality in fresh, groundZater,
and seaZater samples.
(iii)
The potential for undertaking small sample analysis, from, for e[ample, plant
e[tracts or seeds, Zhere the loZer detection limits of ICP-MS enables smaller
sample sizes to be analysed than can be done by other methods. This avoids the
necessity for preconcentration steps that introduce the possibility of
contamination or analyte loss.
(iv)
Rapid, simultaneous analysis Zith typical sample throughput times of 2-
minutes (inclusive of Zashout betZeen samples). This is e[tremely important in
environmental studies Zhere large sample numbers are normally involved.
(v)
The direct analysis of many heavy metals (Cd, Hg, Pb) and radiogenic elements
provides an e[cellent facility for undertaking pollution studies.
(vi)
LoZ detection limits for many elements not readily determined by other
analytical techniTues (Li, %, %e, Si, rare earth elements).
(vii)
The e[panding range of sample introduction techniTues, including conventional
pneumatic, ultrasonic, and high-solids nebulizers, floZ-injection, electrothermal
volatilisation, and laser ablation can be applied to a Zide variety of
42
environmental matrices. Most analytical techniTues reTuire either sample
dissolution or separation steps, and large sample masses.
(viii)
The ability to determine isotope ratios provides the opportunity to undertake
tracer and speciation studies (:ard, 199)
2..2
Ph\ViFal aQG &hemiFal PriQFipleV
The ICP, hoZever, is estimated to produce a ma[imum temperature of at least 6
o
K. This e[tremely high temperature is sufficient to break almost all chemical bonds in a
sample, giving rise to monoatomic ions that are virtually independent of one another. As a
result, the techniTue e[hibits high sensitivity, four or more orders of magnitude linear range,
and much loZer spectral interferences than emission techniTues (:endt and Fassel, 196).
The ICP is therefore a very efficient ion source that is particularly suitable for mass
spectrometry.
Samples are most commonly introduced into the plasma as aerosols. A Zide variety
of devices are available for sample introduction. Pneumatic nebulizers are the least
e[pensive and most commonly used in commercial devices. The aerosol produced by the
nebulizer is generally passed through a spray chamber to remove large droplets and produce
a more homogenous aerosol. :hile passing through the plasma, the aerosol is vaporized,
atomised, and ionised. After leaving the e[tremely hot plasma, the ions are e[tracted from
the plasma through an orifice (typically 1 mm in diameter) into a Tuadrupole mass
spectrometer. A system of electronic lenses is used to focus the ion beam before entrance
into the mass filter.
As noted above, a Tuadrupole is the typical mass analyser in ICP-MS, although some
Zork has been done Zith the time-of-flight (T2F) mass spectrometers and magnetic sector
mass analysers have been used for higher resolution. The block diagram of inductively
coupled plasma mass spectrometry is shoZn as in Figure 2. (Greenfield, 1964). The
instrumentation of inductively coupled plasma- mass spectrometer is shoZn in Figure 2.1.
43
Mass
filter
Lens
system
Mass
spectrometer
interface
RF
generator
Sample introduction
system
Detector
Computer
Plasma
source
Printer
FiJXre 2.0
FiJXre 2.
%lock diagram of an ICP ±MS system
Instrumentation of ICP-MS system
Data may be accumulated in either continuous scanning or peak-hopping mode. The
continuous-scanning mode reTuires e[cellent resolution to avoid interferences from adjacent
peaks but is more forgiving of fluctuations in precise correlation betZeen detected mass and
Tuadrupole performance. Peak hopping, on the other hand, reTuires e[tremely good
reproducibility of mass positions, but reTuires only moderate resolution. In theory,
continuous scanning is slightly more accurate because response shifts and fluctuations in
plasma parameters are less likely to affect total integrated signal, Zhereas peak hopping is
theoretically more sensitive because measurements are taken near the centre of mass of the
response peak. In practice, hoZever, either techniTue provides acceptable sensitivity and
accuracy.
44
2..3
GeQeral UVeV aQG AppliFatiRQ
ICP-MS is a destructive method, but only a feZ milligrams or millilitres of samples
are reTuired. 2ther general uses of the ICP-MS are determination of trace impurities in
semiconductor raZ materials, intermediates, and finished products, determination of ultra
trace elements in geochemistry and determination of elemental composition of unknoZn
materials. The use of stable isotopic tracers as an alternative to radio isotopic tracers can
also be done using the ICP-MS system. Furthermore, determination of trace elements for
environmental compliance and determination of radionuclides is achievable (Mizuike,
193).
ICP-MS is a major tool for geochemistry. Its speed, e[cellent sensitivity, accuracy,
and long linear range alloZ rapid, precise analysis of a Zide variety of minerals for minor
and trace components. ICP-MS affords superior resolution for determination of rare-earth
elements (REEs). Another useful attribute is superior sensitivity and detection limits for the
platinum group elements. ICP-MS is also used to good advantage in biological and medical
research. The speed, accuracy, and large number of elements that can be determined in a
single analysis make ICP-MS a very cost effective techniTue (Gray and Date, 199).
2..3. State, AmRXQt aQG PreparatiRQ RI SampleV
Samples are most commonly presented to the instruments in liTuid form hoZever,
most solids may be Tuantitatively dissolved to permit analysis as solutions. Laser ablation
accessories are readily available for most commercial inductively coupled plasma mass
spectrometry (ICP-MS) instruments, so direct solids analysis is more commonly used Zith
ICP-MS than ICP-AES.
Solids typically mg of an inorganic material are dissolved in mL of solution.
Smaller sample masses may be used but sensitivity Zill be degraded furthermore, for
inhomogeneous materials, it may be difficult to prepare a representative sample. It is also
desirable to reduce total solids as much as possible Zithin the constraints of reTuired
detection limits. FloZ injection techniTues may be used to reduce the total mass of material
introduced into the mass spectrometer. 2rganic materials may be dry ashed in crucibles or
loZ-temperature plasma ashers, or Zet ashed in a high-pressure asher, a microZave oven, or
4
an open beaker.
Although the ICP source is very robust, the analyst should minimize the differences in
composition betZeen the samples and the standards to achieve ma[imum accuracy.
ATueous samples are acidified to a pH of less than 2 Zith redistilled nitric acid to minimize
analyte precipitation. Samples should be prepared and stored in Teflon, polyethylene, or
similar vessels. Glass vessels should not be used for aTueous solutions because they tend to
release contaminants or adsorb analytes. Common acids, such as hydrochloric acid and
sulphuric acid, give rise to polyatomic spectral interferences not commonly encountered in
ICP-AES. Nitric acid does not increase background intensities significantly because the
amount of nitrogen arising from nitric acid in the original sample solution.
2..4
&aliEratiRQ aQG StaQGarGi]atiRQ
After initial calibration is successful, a calibration check is reTuired at the beginning
and end of each period during Zhich analyses are performed, and at reTuisite intervals. The
instrument must be calibrated for the analysis to be determined using the calibration blank
and calibration standards prepared at one or more concentration levels. A minimum of three
replicate integrations is reTuired for data acTuisition. AlloZ sufficient rinse time to remove
traces of the previous sample or a minimum of 1 min. Solutions should be aspirated for 3
sec prior to the acTuisition of data to alloZ eTuilibrium to be established (USEPA, 1992).
2..5
AQal\ViV Time
Instrument Zarm up and calibration reTuire 3 to 6 min. During this time, hoZever,
the analyst may check mass calibration and optimise lens voltage, torch alignment, and gas
floZs, either manually or under computer control. After the instrument is ready for
operation, aspirating a sample, alloZing the system to come to steady state, acTuiring data
for the entire mass range, and Zashing out the system reTuires altogether about 3 min for a
Tuadrupole ± based instrument. High-resolution magnetic sector instruments reTuire
considerably more time 1 min is typical for optimal sensitivity. Isotope ratio e[periments
typically reTuire about 7 sec per mass the analysis time depends on the correction of total
46
analyte and the relative abundances of the isotopes of interest. Instruments Zith multiple
detectors reduce analysis time and improve accuracy and precision, but are considerably
more e[pensive than instruments Zith a single detector. Almost all commercial ICP-MS
instruments are very fast seTuential-scanning devices. 2btaining acceptable accuracy and
precision for a full-spectrum analytical scan typically reTuires about 2 min. Commercial
instruments, hoZever, afford the analyst great fle[ibility in selecting the mass ranges of
interest. Auto sampling devices alloZ unattended operation and most modern instruments
include softZare to perform 4C check routine and even shut doZn the instrument at the end
of a run (Nia and Houk, 1996).
2..6
4XaQtitatiYe AQal\ViV
Several techniTues are available for Tuantitative analysis. They include (i) direct
calibration, (ii) standard addition, and (iii) isotope dilution. These techniTues can be used in
either the single-element or multi element mode.
In direct calibration, intensities of specific mass spectral peaks are obtained by
tuning the mass spectrometer to a value of m/z characteristic of each isotope of the elements
to be determined. A predetermined integration of the ion current is performed at selected
m/z values for each element to be analysed, using the peak-hopping procedure. Mi[ed
aTueous standards of knoZn concentration are run in the same fashion, under the same
instrumental conditions as the samples. Estimates of the concentration of the analyte metals
are determined by comparing the ion currents obtained from the scans of the standards to
those obtained for the samples. Integration times are chosen to ma[imize measurement
precision.
Ion currents for each analyte are measured for a series of calibration standards at
various concentration levels. In the multi-element mode, mi[ed standards Zith compatible
analytes are used to establish calibration curves for each element. Curves are generally
linear over very Zide concentration ranges, thereby usually alloZing analysis to be
performed Zithout the reTuirement for dilution or preconcentration. Concentrations of the
analytes are computed from the calibration curves. The greater the number of standards
employed in establishing the calibration curves, the better the accuracy of the determination,
due to the closer bracketing of the unknoZn.
47
A minimum of five concentrations is recommended to adeTuately establish a functional
calibration curve (Taylor, 199).
2..
LimitatiRQ aQG IQterIereQFeV
Matri[ effects are more common and more severe than for ICP-AES. Solutions Zith
high solids concentrations may plug orifice. Detector lifetime may be severely reduced by
e[posure to more than a feZ parts per million of any isotope hoZever, most commercial
instruments include detector protection in the hardZare and softZare. 2rganic solutions
reTuire addition of o[ygen to the plasma or sample pretreatment to avoid plugging orifice
Zith elemental carbon.
Polyatomic interferences arising from solvent species and argon cause severe
degradation of detection limits for several important elements (silicon, sulphur, potassium,
calcium, iron, and possibly arsenic and selenium) for conventional Tuadrupole-based
instruments. Initial capital cost, routine maintenance, and time and effort reTuired are all
greater than for ICP-AES. High-purity reagents and e[treme caution to avoid contamination
and loss are reTuired to optimise sensitivity and accuracy (Crain and Kiely, 1996).
Several interference sources may cause inaccuracies in the determination of trace
elements by ICP-MS. These are:
Ɣ
Isobaric elemental interferences: They are caused by isotopes of different elements
Zhich form singly or doubly charged ions of the same nominal mass-to-charge ratio
and Zhich cannot be resolved by the mass spectrometer in use. All elements
determined by this method have, at a minimum, one isotope free of isobaric
elemental interference. 2f the analytical isotopes recommended for use Zith this
method, only molybdenum-9 (ruthenium) and selenium-2 (krypton) have isobaric
elemental interferences. If alternative analytical isotopes having higher natural
abundance are selected in order to achieve greater sensitivity, an isobaric
interference may occur. Measuring the signal from another isotope of the interfering
element, and subtracting the appropriate signal ratio from the isotope of interest must
correct all data obtained under such conditions. A record of this correction process
should be included Zith the report of the data. It should be noted that such
4
corrections Zould only be as accurate as the accuracy of the isotope ratio used in the
elemental eTuation for the data calculations. Relevant isotope ratios and instrument
bias factors should be established prior to the application of any corrections.
z
Abundance sensitivity: It is a property defining the degree to Zhich the Zings of a
mass peak contribute to adjacent masses. The abundance sensitivity is affected by
ion energy and Tuadrupole operating pressure. :ing overlap interferences may
result Zhen a small ion peak is being measured adjacent to a large one. The potential
for these interferences should be recognized and the spectrometer resolution adjusted
to minimize them.
z
Isobaric polyatomic ion interferences: They are caused by ions consisting of more
than one atom Zhich have the same nominal mass-to-charge ratio as the isotope of
interest, and Zhich cannot be resolved by the mass spectrometer in use. These ions
are commonly formed in the plasma or interface system from support gases or
sample components. Such interferences must be recognized, and Zhen they cannot
be avoided by the selection of alternative analytical isotopes, appropriate corrections
must be made to the data. ETuations for the correction of data should be established
at the time of the analytical run seTuence as the polyatomic ion interferences Zill be
highly dependant on the sample matri[ and chosen instrument conditions.
z
Physical interferences: They are associated Zith the physical processes, Zhich
govern the transport of sample in the plasma, and the transmission of ions through
the plasma-mass spectrometer interface. These interferences may result in
differences betZeen instrument responses for the sample and the calibration
standards. Physical interferences may occur in the transfer of solution to the
nebulizer (e.g., viscosity effects), at the point of aerosol formation and transport to
the plasma (e.g., surface tension), or during e[citation and ionisation processes
Zithin the plasma itself. High levels of dissolved solids in the sample may contribute
deposits of material on the e[traction and/or skimmer cones reducing the effective
diameter of the orifices and therefore ion transmission. Dissolved solids levels not
e[ceeding .2 (Z/v) have been recommended to reduce such effects. Internal
standardization may be effectively used to compensate for many physical
interference effects.
z
Memory interferences: It results Zhen isotopes of elements in a previous sample
contribute to the signals measured in a neZ sample. Memory effects can result from
49
sample deposition on the sampler and skimmer cones, and from the build up of
sample material in the plasma torch and spray chamber. The site Zhere these effects
occur is dependant on the element and can be minimized by flushing the system Zith
a rinse blank betZeen samples. The possibility of memory interferences should be
recognized Zithin an analytical run and suitable rinse times should be used to reduce
them. The rinse times necessary for a particular element should be estimated prior to
analysis. This may be achieved by aspirating a standard containing elements
corresponding to ten times the upper end of the linear range for a normal sample
analysis period, folloZed by analysis of the rinse blank at designated intervals. The
length of time reTuired to reduce analyte signals to Zithin a factor of ten of the
method detection limit, should be noted. Memory interferences may also be assessed
Zithin an analytical run by using a minimum of three replicate integrations for data
acTuisition. If the integrated signal values drop consecutively, the analyst should be
alerted to the possibility of a memory effect, and should e[amine the analyte
concentration in the previous sample to identify if this Zas high. If memory
interference is suspected, the sample should be reanalysed after a long rinse period
(USEPA, 1992).
2.2 FlRZ IQMeFtiRQ
ICP-MS is approaching the end of its first decade of development and is noZ an
accepted analytical techniTue for rapid and accurate multi-element determination of ultra
traces in various types of samples. ICP-MS can also be considered as a very fle[ible
detector Zhich is compatible Zith other sample introduction systems, e.g., floZ injection,
laser sampling, electro thermal vaporization (ET9), high-performance liTuid
chromatography (HPLC), ultrasonic nebulization. Although most elements in the Periodic
Table are ionised Zith an efficiency of more than 9 in the argon plasma, mercury, Zith
an ionisation potential of 1.43 e9, is ionised Zith only 32.31 efficiency. This results in a
decrease in detection poZer for mercury. In samples containing very loZ concentrations or
samples, Zhich have to be diluted in order to diminish matri[ effects, detection capabilities
became restricted, making analysis difficult. Preconcentration procedures improve
sensitivity, and usually the detection limit achievable. FloZ injection (FI) sample
preconcentration methods reduce the risks of contamination since FI systems are closed.
This is especially important for the determination of ng L ±1 concentration Zhere high blank
signals could lead to deterioration in precision of the signal to background ratio and
degradation in detection limit. FloZ injection analysis (FIA) Zas first described by Ruzicka
and Hansen and, since then, has emerged as a versatile sample handling tool, Zhich can
enhance considerably the analytical capabilities of atomic absorption (AA), ICP-optical
emission spectroscopy (2ES) and ICP-MS (Chen and Jiang, 1996).
In the presence of floZ injection (F. I) techniTue, a simple continuous-floZ HG
system Zithout the conventional gas-liTuid phase separator has been employed as a sample
introduction device for FI-ICP-MS analysis. :ith this system, only minimal and
ine[pensive modification of the e[isting standard eTuipment is reTuired. These
combinations of the (FI) techniTue to ICP-MS reTuire minimal sample consumption (a 1
PL per injection) Zith high sampling rate. It is very simple and rapid techniTue. It also
reduced the problems of matri[ interferences.
2.2.
H\GriGe GeQeratiRQ
Some elements form hydrides, Zhich are gaseous at ambient temperatures. These
can be generated easily from aTueous solution in a reducing environment. Mercury is
reduced to its volatile elemental form in the same reaction. The most freTuently used
method of hydride generation is the acid ±borohydride reaction.
Na%H4 3H22 HCl
H3%24 NaCl H-----Em---
E Hn H2
:here E hydride forming elemental interest and may or may not eTual n. A number of
e[perimental variations have been utilized to effect this reaction, such as alternative
reducing agents or acids. Although generation of the hydride itself is relatively
straightforZard, it is essential that it is transported Tuantitatively and reproducibly, and
introduced Zith the minimum distribution of the plasma. The batch hydride generation
method involves reacting an aliTuot of sample solution Zith an aliTuot of Na%H4 in a
syringe. The syringe needle is then inserted into the uptake tube of the ICP and the gaseous
products injected directly into the plasma.
1
2.3 NeXtrRQ AFtiYatiRQ AQal\ViV
Neutron activation is the irradiation of a nucleus Zith neutrons to produce a
radioactive species, usually referred to as the radionuclide. The number of radio -nuclides
produced Zill depend on the number of target nuclei, the number of neutrons and on the
factor called the cross section, Zhich defines the probability of activation occurring. If the
activation product is radioactive, it Zill decay Zith a characteristic half-life (Parry, 1991).
2.3.
PriQFipleV RI IQVtrXmeQtal NeXtrRQ AFtiYatiRQ AQal\ViV
Neutron activation analysis has become a mainstay of geochemical and biochemical
trace element research because the techniTue possesses several important advantages. This
includes, substantial freedom from systematic errors, it is complementary to other methods,
freedom from analytical blank and other problems related to dissolution, multi-element
capability, sensitivity at sub-picogram amounts. These characteristics of nuclear methods
have been Zidely e[ploited, particularly in research into trace element analytical
methodology.
The physical phenomena upon Zhich NAA are based are the properties of the
nucleus, radioactivity, and the interaction of radiation matter. The seTuences of events
during a typical (n, Ȗ) reaction are illustrated in Figure 2.2. :hen a neutron interacts Zith a
target nucleus by a non-elastic collision, a compound nucleus is formed in a highly e[cited
state. The high e[citation energy of the compound nucleus Me9 on the average is due to
the high binding energy of the neutron Zith the nucleus. The lifetime of the compound
nucleus is typically 1-16 to 1-14 s. This is long enough that no traces remain to identify the
particular process of formation, but short enough that the nucleus can undergo a rapid dee[citation to a more stable configuration, in a number of different Zays that usually involve
emission of nuclear particles or prompt gamma rays. In most cases, the neZ nucleus is
radioactive and Zill further de-e[cite by emitting decay gamma rays. The NAA method
relies on the measurement of either these characteristic prompt or decay gamma rays for
identifying elements and determining their amounts present in samples. About 7 of the
elements have nuclides possessing properties suitable for NAA (IAEA, 199).
2
The techniTue is noted for its precision and that is Zhy it is freTuently used as a
reference techniTue for the development of reference materials. The main limitation to
precision is due to the counting statistics in the gamma ray spectrometry and usually it is
possible to improve precision by long counting times. The e[ceptions to this are elements
that activate to give short-lived radio -nuclides (Parry, 1991). The techniTue is generally
used for trace element analysis for multielements. The detection limit is at the microgram
level for many elements and doZn to nanogram Tuantities for some. HoZever, the detection
limit Zill depend on the other elements present in the matri[ (Kruger, 1971).
The method can be used to determine elements at a Zide range of concentrations
since the calibration ³curve´ is actually a straight line. In theory, the method can be used to
measure elements over concentration ranges from nanograms to grams. HoZever, if the
element is present in too high a concentration there is a possibility of self-shielding, Zhich
may reduce the specific activity of the radionuclide produced. The time for an analysis
depends on the elements to be measured. If the element activates to give a short-lived
nuclide, it may be irradiated and counted in a feZ minutes. 2n the other hand, some
elements may be analysed using an irradiation of several Zeeks and left for months before
counting for many hours. The timings are relatively fle[ible for the longer-lived
radionuclides and the analysis can take as long as there is time available (Seiler, 1994).
3
ȕ
Ȗp
PROMPT GAMMA RAY
|
A
A
; }
= ; }
TARGET
NU&LEUS
RADIOA&TIVE
NU&LEUS
=
AA
;;
==
|
}
}
A = ȘȘ
|
|
IN&IDENT
NEUTRON
A
A
Y
STABLE
NU&LEUS


;
;
=
=
DE&AY GAMMA RAY
ȖG
&OMPOUND
NU&LEUS
FiJXre 2.2
reaction
Schematic diagram illustrating the seTuence of events for a typical (n,Ȗ)
NAA has been applied to a Zide range of sample types including biomedical
samples, for e[ample blood, tissue, hair, teeth and bones environmental samples such as air
filters, Zater, plant and vegetation geological samples including rocks, minerals and ores
and a variety of industrial applications Zith carbon and boron matrices, organics, metals and
alloys, glasses and ceramics. Major applications of NAA are archeology, environmental
science, forensics, geology and geochemistry, industrial products and applications,
medicine. In addition to that, INAA can also be applied to a number of materials from the
aTuatic environment, such as aTuatic Zater plants, fish, molluscs, sediments and Zater. In
general, NAA is one of the most sensitive methods for multielements analysis, Zith
inductively coupled plasma emission spectrometry and inductively coupled plasma mass
spectrometry (Alfassi, 2).
4
:ith the use of automated sample handling, gamma-ray spectrum measurement Zith
solid-state detectors, and computerized data processing it is often possible to measure more
than thirty elements Zithout chemical separations. This application of purely instrumental
procedures for trace element analysis is freTuently called instrumental neutron activation
analysis (INAA) (IAEA, 199).
The most common approach to NAA is the ³comparator´ method, Zhich is
commonly accepted as the most accurate Zay to Tuantify element concentrations. In this
method, samples are irradiated simultaneously Zith standards containing knoZn amounts of
the elements. After irradiation, both samples and standards are measured under identical
geometrical conditions Zith the same detector. This procedure eliminates uncertainties in
the nuclear parameters, detector efficiencies, etc. and reduces the NAA eTuation for each
element to its simplest form:
:s
As e[p(ȜTDs)
:st
Ast e[p(ȜTDst)
:here
:s
Zeight of element being sought in the sample
:st
Zeight of the element in the standard
Ds
disintegration rate at the end of irradiation for radioisotope measured and
Dst
disintegration rate in the standard at the end of irradiation.
In the multi-elemental analysis of a sample, the comparator method reTuires a large
number of individual elemental standards or use of a Zell-characterized multi-element
standard. Preparation and irradiation of individual standards for each element are timeconsuming and e[pensive and the use of reference materials is not alZays practical because
of the limited accuracy for certain elements or the differences betZeen sample and standard
matrices.
2ne of the draZbacks of INAA, sometimes mentioned Zhen considering its use in a
monitoring program, is its relatively long turn-around time, Zhen compared to other
analytical techniTues. Indeed, sometimes 3 or 4 Zeek decay period is reTuired to obtain
highest sensitivity. HoZever, many elements can often be determined Zith adeTuate
sensitivity after shorter decay times. Moreover, INAA Zith short-half life nuclides may also
provide a very rapid ansZer. The other draZback of INAA, especially Zhen environmental
studies are involved, is its inadeTuacy of determining lead- often one of the prime elements
of interest in pollution studies.
In general, INAA may be the first choice for materials from the applied fields Zhich
are difficult to convert into solution for analysis, e.g., via AAS or ICPMS and/or of Zhich
only milligram Tuantities are available.
2.3.2
DeFa\
As Zith any radioactive source, the induced activity in an irradiation sample
decreases as time passes. The rate of decrease is e[ponential and varies Zith the individual
isotope. The period of time taken for the activity to decrease by one half is knoZn as the
half-life (Tò). The manner of decay of radioactivity may be e[pressed mathematically by
the eTuation,
At
Ao (e ± .693t)
Tò
:here Ao
At
initial activity (dis/ unit time: dis/ sec, dis/min)
activity remaining after time t
Tò half-life, e[pressed in convenient units
t
elapsed time, in same units as Tò
e
base of natural logarithms(Lyon, 1972)
6
2.3.3
NXFlear ReaFtRrV
Governments or universities form the basis for multidisciplinary research institutes
commonly purchase nuclear research reactors. In many countries there is only one research
reactor and it is intended to support the scientific and technical development of the Zhole
country. A research reactor is a major investment and it is also e[pansive to run. Therefore,
it is important to use it efficiently. The research reactor is the most Zidely used source of
neutrons for INAA, particularly Zith respect to the number of samples processed and the
number of elemental analysis performed. Five general types of research reactors are
described: SloZpoke, Argonaut, TRIGA, Pool and Heavy :ater. The groups are not
mutually e[clusive and overlap in some respect, e.g., TRIGA reactors are of the Pool type
(IAEA, 199).
The cost depends on the detection limits reTuired and Zhich elements are to be
measured in Zhat matri[. Typical commercial charges are competitive Zith other
techniTues, Zhich provide an eTuivalent range of elements and detection limits. The main
potential cost is that of running a nuclear reactor. Normally the reactor Zill have been built
for some other purpose, such as nuclear research and training, materials testing and isotope
production. Neutron activation analysis is a useful by-product of the operation of the reactor
and therefore the cost of irradiations can usually be kept to an affordable level.
Typical reactors used for neutron activation include the Canadian SloZpokeŠ reactor,
the American TRIGAŠ reactor and other pool type reactors. The TRIGAŠ reactor is designed
as a general purpose reactor but has incorporated in its design the facility for flu[
eTualization systems Zhich make it very suitable for activation analysis. Most of the trace
elements of interest may be detected by activation of a stable nucleus Zith thermal neutrons.
7
2.3.3. TRIGA ReaFtRrV
TRIGA reactors are a popular multi-purpose type. They range in poZer levels from
1 k: to 3 M: Zith 2 k: and 1 M: being the most common operating levels. These
reactors operate Zith uranium-zirconium hydride homogenous solid fuel Zith an enrichment
of either 1 or 7 . The reactors are light Zater cooled, graphite reflected and of the
pool type. Most TRIGA reactors are capable of operating in the pulse mode and most have a
rotary specimen rack (called Lazy Susan) containing 4 irradiation positions betZeen the
core and the reflector.
2.3.3.2 RRtar\ SpeFimeQ RaFk (La]\ SXVaQ)
Neutron activation analysis is based on the principle that induced activity is
proportional to neutron flu[ and therefore any Tuantitative measurements rely on the
neutron flu[ being reproducible or Tuantifiable. The best Zay to do this is to keep the flu[
as constant and reproducible as possible. 2n the TRIGAŠ reactor this is achieved using a
rotating irradiation device, Zhere the samples travel sloZly round the perimeter of the core
so that all the samples see the same integrated flu[ during an irradiation. The main
disadvantage of eTualization systems is that by their nature the samples Zill all see an
average flu[, obtained by travelling through regions of high and loZ neutron density.
In the TRIGA reactors, samples can be irradiated in the reflector, in the ³rotary
specimen rack´ (Lazy Susan), in Zhich there are 4 locations Zhich can hold capsules 3 cm
in diameter and 2 cm long. This rack can be rotated. In some laboratories, the rack is
rotated during irradiation in order to get a homogenous flu[ for all samples.
2.3.4
IrraGiatiRQ &RQtaiQerV aQG Sample EQFapVXlatiRQ
The samples to be irradiated for activation analysis must be contained in some Zay.
The material of the container should not itself become too radioactive otherZise it Zill
create a hazard to handlers. It has to stand the effects of radiation, heat and mechanical
impact. Polyethylene is generally used for thermal neutron irradiations since high purity
grade polyethylene contains very feZ impurities that activate significantly Zith thermal
neutrons. It is cheap and it can be easily fabricated in different sizes and forms.
Polyethylene can also be easily heat-sealed using a conventional soldering iron, Zhich
makes preparation simple. %ecause polyethylene is relatively pure it is often possible to
count the activated capsule Zith its contents, Zithout transferring the sample to a neZ
container. Table 2. shoZs the impurity concentrations of polyethylene. Polyethylene vials
can be marked Zith Zaterproof ink from a pen intended for overhead transparencies (IAEA,
199).
2.3.5
Gamma Ra\V
The principle of activation analysis is to induce radioactivity in the element of
interest. Decay products are then detected and identified by their energies Zhile the decay
rate is used to make a Tuantitative determination of the target element. In general, gamma
rays are the most suitable form of radiation for multielemental analysis. The best gamma ray
lines are selected on their abundance, Zhich is defined from the mode of decay. The decay
schemes are used to find the branching ratios or gammas per disintegration. Finally, the
gamma rays are detected Zith a semiconductor detector, based on the interaction of the
photon Zithin a pure material.
9
TaEle 2.0 : Concentration of impurities in polyethylene and Tuartz
ElemeQt
Ag
Al
As
%r
Ca
Cd
Cl
Co
Cr
Cs
Cu
I
Fe
Hg
K
Mg
Mn
Mo
Na
Ni
Rb
Sb
Se
Sn
Sr
Ti
Th
U
Zn
PRl\eth\leQe (QJ/J)
± 1
1 ± 14
1 ± 3.14
.7 ± 1
1 ± 3
.
1 ± 17
1 ± 1
1 ± 14
1- 1
1 ± 1 4
±1
1 ± 1
4 ± 1 .1 ± 1
1 ± 1
1 ± 1
1 ± 14
.13
3
4
2 - 14
4Xart] (QJ/J)
1 ±1
.17 ± 1
1 ± 1
1 ± 1
1 ± 1
1 ± 14
.3 ± 1
1.6 ± 1
.12
2 ± 1
1 ± 14
.3
1 ± 14
1 ± 1
1 ± 1 ± 2 ± 2
.4 ± 1
.7 ± 1
.46 ± 1
2 - 4
Source : Practical Aspects of 2perating a NAA Laboratory, IAEA 199
6
2.3.6
&RXQtiQJ aQG Data PrRFeVViQJ FaFilitieV
2ne of the steps of every INAA procedure is the measurement of induced
radioactivity Zhich, Zith a very feZ e[ceptions, is being done by gamma-ray spectrometry.
The basic set-up of a gamma-ray spectrometer for use in INAA is shoZn in Figure 2.3. It
consists of a semiconductor detector Zith associated preamplifier, a high-voltage poZer
supply, a spectroscopy amplifier, an analogue-to-digital converter (ADC), a multi-channel
pulse height analyser (MCA), and a computer-system Zith input/output facilities.
HIGH
92LTAGE
SUPPLY
PREAMPLIFIER
GERMANIUM
DETE&TOR
FiJXre 2.3
SPECTR2SC2PY
AMPLIFIER
&OMPUTER
ANAL2G T2
DIGITAL
C2N9ERTER
MULTI
CHANNEL
PULSE-HEIGHT
ANALYSER
Schematic set-up of gamma ray spectrometer for use in INAA
2.3.6. SemiFRQGXFtRr DeteFtRrV
For application in INAA, only germanium detectors are of importance. Germanium
semiconductor detectors e[ists in tZo versions, Lithium drifted germanium detectors or
knoZn as Ge(Li) detectors and Hyperpure (HP-) or intrinsic germanium detectors. In a
Ge(Li) detector, lithium ions have been drifted into the crystal structure, thus compensating
for impurity centers and forming an intrinsic or active region. 2ne of the advantages of HPgermanium is that Zell-type detectors can be more easily fabricated and repaired than ever
Zas attainable Zith Ge(Li) material, resulting also at more practical large Zell-diameters (up
to 2 mm have been reported), and at highly competitive prices. Semiconductor detectors
are operated at liTuid nitrogen (LN2) temperature (77K). The crystal is mounted in a
vacuum cryostat, thermally connected to a copper rod, the µcold finger¶.
61
This cold finger transfers the dissipated heat from the crystal to the cooling medium. Ge(Li)
detectors have alZays to be stored at LN2-temperature Zarming up leads to almost
irreparable damage. HPGe detectors can be stored at room temperature Zithout damaging
the crystal as long as the H9 bias is removed.
There are a number of detection devices available for radiation characterization.
These include ion chambers, gas counters, Geiger-Muller counters, scintillation counters,
spectrometers, and semiconductor detectors.
2.3.
4XalitatiYe AQal\ViV
Although activation analysis is usually considered a Tuantitative method for trace-
element analysis, the techniTue can be used for rapid and sensitive Tualitative analysis. The
method is based on the fact that most radionuclides e[hibit characteristic beta and gamma
ray energies and half-lives. It is only necessary to characterize the radiations from an
irradiated sample, using the appropriate detection apparatus, and relate these characteristics
to sample composition (Lyon, 1972).
2.3.8
4XaQtitatiYe AQal\ViV
2ne can e[pand the above techniTue to do not only Tualitative analysis but also
Tuantitative analysis. This modification is possible since the induced activity due to a
particular element in a sample is proportional to the amount of that element in the sample
(under a given set of irradiation conditions).
CHAPTER 3
MATERIALS AND METHOD
3.0
Introduction
This chapter describes the materials and the methodologies used for heavy metals
pollution assessment in the Sg. Skudai river system and its aquatic habitats. The study area
is also described. The rational for the selection of monitoring stations, parameters
measured, sampling frequency, sampling methodology, methods of analysis and statistical
analysis are explained.
3.1
Study Area
This study was conducted in the Sg. Skudai river basin that starts from Kg.
Sedenak (longitude 1030 32’T and latitude 10 45’U) and Bukit Ular (longitude 1030 33.5’T
and latitude 10 45.5’U) in Kulai District which is around 40 km of land and flows
southwards to the coastal plains of Selat Tebrau Barat (longitude 1030 43.5’T and latitude
10 27.5’U). The river flows through the local authority administration area of Majlis
Daerah Kulai (MDK), Majlis Daerah Johor Bahru Tengah (MDJBT) and Majlis
Bandaraya Johor Bahru (MBJB) as shown in Figure 3.0. The basin covers an area of 4456
hectares and consists of Mukim Tebrau, Tampoi, Pulai, Senai, Kulai and Sedenak. Sg.
Skudai river has two main tributaries upstream namely Sg. Senai, which joins in at Senai
Town and Sg. Melana which joins Sg. Skudai about 1 km from Kolej Selatan. Both rivers
flow from the South West direction. The main tributaries downstream that flows into Sg.
Skudai within the MBJB area, consists of Sg. Kempas and Sg. Danga making their way
through housing areas, industrial settlement and commercial centres.
63
Pollution sources and sampling stations of the Sg. Skudai river system are
available at Figure 3.1. At the upstream region of the Sg. Skudai, close to the first
sampling point (Kg. Melayu Sedenak) there are not many large scale industries, but only
some small workshops and very little shop houses operating as small scale industries for
wood processing, food processing and engineering companies. Here agricultural activities
are observed more than any other parts of the river. A huge oil plam plantation exists and
an oil palm mill is operating in this plantation. Besides that, there are a few pig farms
around this area. Other domestic wastes are also found here due to a large number of
estate houses and a Malay village at this area.
The second sampling point (Sengkang), which is also located at the upstream
region of the river, is also found to be active with agricultural activities such as small scale
oil palm plantation and large estates of rubber plantation. A rubber factory is found to be
operating here. Besides that some wood processing factory, marble and tiles factories,
leather, electronics and some metal engineering and concrete companies are also present.
Meanwhile, the third sampling location (Tmn. Mewah) is located beside a settlement and
some lorry body work and car repair workshops that are functioning actively. River is also
polluted with domestic wastes due to a squatter area at this sampling point.
Kg. Pertanian, the fourth sampling point is located below a bridge with some
textile industries and wood industries operating at this area. On the other hand, sampling
point 5 (Saleng) is located at an oil palm estate beside a railway track. Near to this point is
a dumping site for Majlis Daerah Kulai and there is also an oil palm mill. The next
sampling point (6) (Kg. Jaya Sepakat) is located near to the PUB at Skudai. This area is
surrounded by squatters and it is the PUB water intake point. Industries almost don’t exist
at this area of the river.
Sampling point 7 (Tmn. Teratai) is located near a major settlement and close to an
oxidation pond. There are still lots of construction works carried out at this area, especially
maintenance and upgrading of some facilities at the Pulai Springs Resort. While, sampling
point 8 is located right at a major settlement of Taman Universiti. Here, small scale
industries like painting, food, electronics, metal engineering, gloves, motorcycle
workshops and car workshops are operating. Some construction works are also taking
place here. Besides that, there is a oxidation pond near to this sampling point.
64
A settlement is at sampling point 9 (Gelang Patah), this point is a construction area
where terrace houses are being built. This point is located on the way to Gelang Patah
from Tmn. Universiti, after Mutiara Rini. There are also some agricultural activities such
as cow farms and oil palm estates here. At sampling point 10 (Kolej Selatan), Lee
Pineapple is operating here. This sampling point is just below a bridge in front of Tmn.
Ungku Tun Aminah. There are a lot of shop houses with small scale industries like food,
electronics, painting and workshops. A petrol station is operating beside the river. A
squatter area is also found beside the river.
As we move on to the next sampling point, sampling point 11 (Tampoi) is located
at the prime industrial zone of the Sg. Skudai river system. This point of the river is now
surrounded by many industries such as electronics, printing, paper, boxes, pharmaceutical,
paint, garment, car and motorcycle workshops, food, electroplating, battery and other
industries. Major settlements are also present here like Tmn. Kobena, Tmn. Tampoi Indah
and Tmn. Sutera. The water here is also polluted with the presence of a oxidation pond, as
the water here is observed to have a lot of bubbles on its surface. Constructions too are
carried out here. Sampling point 12 (Kg. Skudai Kiri) is located in front of Plaza Angsana
almost near to the river estuary. There is a squatter area here and some fishing activities,
but the amount of salt water mixing with the river water is very little here and this factor is
not taken into consideration, as the plant (Phragmite karka) can still be found here. There
is also a wet market operating beside this sampling point.
Sampling point 13 (Kg. Pengkalan Rinting) is located right at the river estuary.
This part of the river is very wide. There are also a lot of fishing activities carried out here.
A small malay village is located beside this part of the river. Meanwhile, Kg. Telok
Serdang, sampling point 14, is located under a bridge, behind a squatter area. There are a
lot of domestic wastes found in this part of the river. There is also a large printing
company operating near this point. Furthermore, this point is surrounded by a large
housing area. Sampling point 15 is located at a malay village. This point is located far
from the Tampoi Town. There are a lot of fishing activities here, because along the road,
there are a lot of people selling fishing baits. The last sampling point, Kg. Sg. Danga is
located just beside a fishing pond beside the Sg. Skudai. This part of the river is opening
out to the sea (Danga Bay). There is a malay village here and the fishing pond is for
recreation purpose, but there are a lot of fish food wastes being released into the river and
also a restaurant is operating here.
66
3.1.1
Landscape
Agricultural plantations such as oil palm and sundry tree cultivations cover the
intervening spaces of the northeastern portion of the river basin. The centre section of the
river basin is an entirely flat land with industrial and agricultural activities scattered
around the river plains. The population density till this section of the river basin is
relatively low and urban centres are widely scattered. The downstream of the river mouth
reaching the coastal plains is the most urbanized section of the basin and very little natural
forest cover is left except for secondary jungles and sundry tree cultivations. A few
patches of peat-swamp forests occur inland while the coastline is intermittently vegetated
by mangrove swamp and strand forests. The soil types near the coastal line are sand and
mud (Director of National Mapping, 1997).
3.1.2
Climate
The climate of the Sg. Skudai basin is equatorial monsoon. Uniform and high
temperatures are observed throughout the year and the mean ambient temperature is about
26.1 0C. The average rainfall in the Sg. Skudai river basin is about 2100 mm and it is
evenly distributed throughout the year. Dry and wet seasons are not well marked and
heavy rainfall may be experienced at any time of the year. During November to January
the frequency of rainfall is higher (Department of Meteorological Services, 1999).
3.2
Selection of Monitoring Stations
Potential sites for monitoring stations were surveyed prior to commencement of
sampling. The survey identified industrial areas, land use patterns and human activities
that could impact the river water and the aquatic habitats at the proposed sampling station.
Pollution sources and sampling stations of the Sg. Skudai are illustrated in Figure 3.1and
types of industries under Sg. Skudai basin is indicated in Table 3.0. Sampling stations
were sited based on the following criteria:
1) Accessibility and ability to sample under all weather conditions;
2) Homogeneity of the water column;
67
Figure 3.1
Pollution sources inventory map of the Sg. Skudai river system and
sampling stations selected along the river.
68
Table 3.0 : Types of industries under Sg. Skudai river system
M. D. KULAI
TYPES OF
INDUSTRIES
Food, Drinks and
Tobacco
TOTAL
%
M.D.JOHOR BHARU
TENGAH
TOTAL
%
6
4.6
208
8.4
Textile, Clothes, Leather
Products
6
7.7
543
21.9
Wood, Wood Products,
Furnitures
10
6.2
88
3.5
Paper, Paper Products,
Printing, Publishing
8
6.2
184
7.4
Chemicals, Petroleum,
Coal, Rubber, Plastic
Products
35
26.9
258
10.4
3
2.3
69
2.8
Basic Metal Industries
28
21.5
92
3.7
Artificial metals,
Machinery, Equipments
(including Transportation,
Electric And Electronic)
22
16.9
987
39.8
Other Manufacturing
Industries
10
7.7
51
2.1
130
100
2 480
100
Non-metal mining
products
Total
Source: Licensing Department Majlis Daerah Kulai (MDK), Majlis Daerah Johor
Bharu Tengah (MDJBT), 1999 Research of RS (P) JB, 1998-2020
69
3) The aquatic habitats present at the site;
4) The main tributaries joining the river; and
5) Location of the industrial areas.
A total of 16 monitoring stations were established along the Sg. Skudai river
(Figure 3.1). Sampling station 1 (Kg. Melayu Sedenak) was selected in the upper reaches
of the river to obtain the status of water quality from relatively undisturbed area of the
river. Major industrial areas identified were Sengkang, Desa Perindustrian Kulai, Taman
Perindustrian Senai, Taman Universiti, Taman Ungku Tun Aminah and the river
downstream, which is a highly industrialized area. Sampling stations for the river
upstream were sited before, at and after each industrial area, because the industrial areas
are widely scattered along the river plains. Meanwhile, sampling stations downstream
were sited randomly at the river mouth and estuary because the major industrial areas at
this part of the river are located near to one another with limited distances between them.
Sampling stations were also sited at Sg. Danga, which joins Sg.Skudai at the coastal line.
The locations of the selected monitoring stations are given in Table 3.1.
3.3
Parameters Measured
A total of 13 water quality parameters were studied. These consisted of three
physical, two organic and eight trace metals (Table 3.2). The water quality parameters
selected for this study included the principal industrial pollutants (Ni, Cd, Hg, Pb, Cr, Cu,
Zn and As) entering the water body of the Sg. Skudai (Kashin and Ivanov, 1994).
70
Table 3.1 : Sampling locations along downstream route of Sg. Skudai
Sampling locations
Coordinates
Description of location
0
N 01 43’ 00. 4”
1
2
E 1030 31’ 12.6”
Kg. Melayu Sedenak
N 010 41’ 30.8”
Sengkang
0
E 103 34’ 18.7
”
N 010 39’ 47.0”
3
4
5
6
7
8
9
10
11
E 1030 36’ 16.3”
N 010 38’ 42.4”
E 1030 37’ 24.9”
N 010 37’ 55.5”
E 1030 38’ 11.9”
N 010 33’20.3”
E 1030 39’ 40.5”
N 010 33’45.9”
E 1030 37’ 02.1”
N 010 31’29”
E 1030 37’ 48.5”
N 010 31’01.4”
E 1030 38’ 13.5”
N 010 31’39.0”
E 1030 40’ 20.8”
N 010 29’ 43.4”
E 1030 42’ 34.0”
N 010 29’ 28.8”
Taman. Mewah
Kg. Pertanian
Saleng
Kg.Jaya Sepakat
Taman. Teratai
Taman Universiti
Gelang Patah
Kolej Selatan
Tampoi
12
E 1030 42’ 32.3”
Kg. Skudai Kiri
13
N 010 29’ 27.5”
E 1030 42’ 05.2”
Kg. Pengkalan Rinting
14
N 010 30’ 06.2”
E 1030 41’ 19.1
Kg. Telok Serdang
15
N 010 28’ 40”
E 1030 42’ 10.7”
Pulai
16
N 010 28’ 26.8”
E 1030 41’ 45.5”
Kg. Sg. Danga
71
3.4
Sampling Frequency
Samplings were carried out six times for a period of 9 months from November
2000 to July 2001 (Table 3.3). The sampling strategy incorporated frequent collections in
order to adequately define transient changes in the concentration of the constituents being
measured. Each time sampling commenced from the upper reaches of the river at Kg.
Melayu Sedenak to the river mouth at Kg. Sg. Danga.
All samples were collected and sent to the laboratory on the same day. Weather
and physical conditions during sampling were recorded. The sampling strategy used to
investigate the chemical quality in rivers and streams usually employs a single sample, or
a series of samples collected simultaneously, that is representative of the entire flow for
the constituent of interest at the sampling point for that specific instant. Chemical analyses
were carried out in the Radiochemistry laboratory, Environmental laboratory and in the
Malaysian Institute for Nuclear Technology Research (MINT), Bangi.
72
Table 3.2 : List of parameters analyzed
Parameters
Unit
Physical Parameters
Temperature
0
pH
mg/L
C
Dissolved Oxygen (DO)
Chemical Parameters
Organics
Biochemical Oxygen Demand (BOD)
mg/L
Chemical Oxygen Demand (COD)
mg/L
Trace metals
Copper (Cu)
Pg/L
Cadmium (Cd)
Pg/L
Chromium (Cr)
P/L
Zinc (Zn)
P/L
Plumbum (Pb)
P/L
Arsenic (As)
P/L
Mercury (Hg)
P/L
Nickel (Ni)
P/L
Table 3.3: Date of samplings carried out in the Sg. Skudai
Sampling
Date of sampling
1
18 November 2000
2
21 February 2001
3
31 March 2001
4
23 May 2001
5
21 June 2001
6
31 July 2001
73
3.5
Sampling Methodology
Water samples were collected manually from each sampling station and were taken
at a depth of 30 cm below the water surface. After determining the depth of the water the
polyethylene pail is placed in a metal holder attached to a string and thrown into the water.
By regulating the rate at which the pail is lowered to the bottom it is possible to obtain a
sample that approximates an integrated sample of the water between the surface and the
bottom. However, the pail should not be allowed to touch the bottom in the sampling to
avoid stirring up of the sediment. At the time of sample collection, the sample container is
rinsed with the sample solution and the rinse portion discarded. Acid washed 5 L capacity
polyethylene bottles were used for storing the water and were brought to the laboratory
within six hours of collection. The water samples were then immediately acidified with
(1+1) HNO3 purchased from Merck,and maintained to a pH < 2 upon receipt in the
laboratory. Normally, 3 mL of (1+1) acid per litre of samples is sufficient for most
ambient water samples. The low pH inhibits adsorption of the metal ions onto the surface
of the container and prevents the formation of trace metal precipitates or the co
precipitation of trace metals with the other major constituents. Chlorine-containing acids,
such as hydrochloric or perchloric acid, should be avoided as a preservative when ICP-MS
methods are to be used for the determination of trace metals. Excess chlorine atoms in the
ion beam produced by the plasma can form many polyatomic ions that can potentially
interfere with the determination of specific trace metals (Taylor, 1989).
Nitric acid is the preferred preservative and can be obtained commercially in a
highly purified form or can be purified. An amount of 150 ml water samples were taken
under cool and dark conditions at each station using glass bottles for biochemical oxygen
demand (BOD) measurement and 100 ml polyethylene bottles were used to collect water
samples for chemical oxygen demand (COD) determination. Concentrated sulphuric acid
from Ajax Chemicals was used to preserve water samples for COD analysis and the pH
was maintained to less than two. In order to ensure integrity, samples must be transported
to the laboratory for analysis in a manner avoiding extreme environmental conditions,
such as excessively high or low temperatures.
74
The sampling methodology for living organisms must be based on the proper
selection of the type of organism and assurance that the sample will be representative.
Before sampling, the plants that were found along the river banks were identified as the
same species (Phragmites karka) based on its leaves, stem and flower heads. This plant
was not found at all sampling locations as depicted in Figure. 3.1. Especially, at the river
estuary, where salt water mixes with river water. Phragmites karka cannot grow in salt
water. That is the reason for it cannot be found at the sampling points close to the river
mouth. It is a type of submerged weed. The plants of about the same size and age were
selected for further analysis in the laboratory. Once the plant was identified and selected, it
was then pulled out from the soils of the river banks. After that, leaves and stems are cut
using stainless steel scissors. Flower heads are not included in the sample, nor is root
material. Then, the samples are collected in perforated polyethylene bags and placed in
refrigerated storage or an ice-chest as soon as possible. They can be safely stored in a
refrigerator for a few days prior analysis. Any areas of very local contamination such as
those receiving roadside dust should preferably not be sampled, unless of course it is this
type of contamination that is being studied.
When sediment is sampled, alteration of the sample and mixing with other
materials must be avoided or at least minimized. Special care must be exercised when the
surface of sediment is sampled. The collected samples must be stored to maintain the
initial conditions. To take samples that retain the layer structure of the sediment a core
sampler is used. This is a PVC tube, which is dropped to the bottom and penetrates to take
a cylindrical sample. A valve arrangement at the top of the tube stops the sample from
falling out as the sampler is brought to the surface. No chemical preservatives are added to
the sediment sample; immediately it is taken it is placed in a plastic bag and refrigerated or
stored in an ice chest.
75
3.6
Labware
For the determination of trace levels of elements, contamination and loss are of
prime consideration. Potential contamination sources include improperly cleaned
laboratory apparatus and general contamination within the laboratory environment from
dust. Sample containers can introduce positive and negative errors in the determination of
trace elements by contributing contaminants through surface desorption processes. All
reusable labware (glass, quartz, polyethylene, Teflon, etc.), including the sample
container, were cleaned prior to use. Labware were soaked overnight and thoroughly
washed with laboratory-grade detergent and water, rinsed with water and soaked for
twenty four hours in 20% dilute nitric acid purchased from Merck, Germany, followed by
rinsing with DDW and oven drying.
3.6.1
Laboratory Apparatus
A number of 25 mL round bottom flasks, Liebig condensers, 50 mm watch glass,
1000 mL and 100 mL volumetric flasks, 50 mL buret, 250 mL conical flasks, funnels,
graduated cylinders, 100 mL beakers and assorted calibrated pipettes were used in this
experiment. A gravity convection oven with thermostatic control and capable of
maintaining 105 0 C ± 5 0C has been used for drying up the laboratory wares.
High quality plastic filter (Nalgene, USA) assembly with suction flask of 500 mL
capacity connected to a vacuum pump aspirator model A-3S (Eyela, Japan), 0.45 µm
Gelman (mixed esters of cellulose materials) membrane filter discs, 5 L and 60 mL
capacity of PTFE sample storage bottles (narrow mouth bottles) with polypropylene screw
cap, 10 mL and 50 mL centrifuge tubes, 10 mL plastic test tubes and Fischer polyethylene
vials (i.d. 10 mm x 20 mm) were used. Apart from that, high quality disposable pipette tips
were used in order to prevent samples from contamination and increase precision.
76
3.7
Sample Processing Equipment
A number of laboratory equipments were used in this experiment for preparing
samples before analysis was carried out. The following describes the equipments used.
A Horiba Water Checker model U-10 was used to take in-situ readings of pH, temperature
and DO of the water body at each sampling location. The instrument was calibrated before
use. A DO meter model YSI model 57 (USA) was used to determine the initial and final
DO of the river water samples for the 5-day BOD test. A Cyberscan 500 pH meter,
capable of proper calibration and reading accuracy of ± 0.2 provided the determination of
pH of the filtered water samples before and also after adding (1+1) nitric acid for
preservation of the water samples. An Edward Modulyo, (USA) freeze dryer was used to
freeze dry the plant and sediment samples before grinding it into powder. This freeze
dryer is connected to a revolving vacuum pump purchased from GCA Precision, Scientific
(USA) and it enables the samples to be dried in cold condition with a temperature of –80
0
C. A Swing Grinding Machine model HSM-100 purchased from Herzog, Germany was
used to grind the dried plants and sediment samples into powder from. This grinding
machine works mechanically to provide fine particle size samples. A centrifuge was used
for separation of undissolved fractions in the sample digest. Samples were centrifuged
with 1400 rpm for 5 minutes. A Retsch mechanical siever was used to sieve the grounded
plant and sediment samples and obtain 75-150 mesh of particle size. A number of assorted
size sievers can be used for different sizes of particles as required by the analyst. A
laboratory analytical balance, capable of weighing accurately up to 0.1 mg was used
throughout the experiment.
3.8
Chemicals and Reagents
Reagents may contain elemental impurities that might affect the integrity of
analytical data. Owing to the high sensitivity of ICP-MS, high purity reagents should be
used whenever possible. All acids used for this method must be of ultra high-purity grade.
Suitable acids are available from a number of manufacturers or may be prepared by subboiling distillation. Nitric acid is preferred for ICP-MS in order to minimize polyatomic
ion interferences. Several polyatomic ion interferences result when hydrochloric acid is
used. When hydrochloric acid is used, corrections for the chloride polyatomic ion
interferences must be applied to all data (USEPA, 1992).
77
In these methods, all acids of ultra high-purity grade were used. Concentrated
HNO3 acid (specific gravity 1.41- Merck, Darmstadt, Germany was used for digestion
procedures. Concentrated H2SO4 acid was purchased from Ajax Chemicals; USA and HCl
acid was purchased from Fischer Scientific, Canada. The 30% H2O2 (Merck, Darmstadt,
Germany) was of analytical grade and NH4OH was purchased from Ajax Chemicals,
USA. HNO3 (1+1) was prepared using deionised distilled water by diluting 500 mL
concentrated HNO3 acid to 1L and (1+9) NH4OH was prepared by diluting 10 mL
concentrated NH4OH to 100 mL.
All chemicals were of analytical grade. FeSO4 (Fluka, Switzerland), K2Cr2O7
(Fluka, Switzerland), Ag2SO4 (Merck, Germany), HgSO4 (Merck, Germany) were used
for the COD determination. NaBH4 (Scharlau, Europe Union), NaOH (Fluka,
Switzerland) and KMnO4 were used for FIMS analysis. Deionized distilled water (DDW)
was used for preparation of solutions, dilutions and for final rinsing of the acid cleaned
vessels. This water was prepared using a Barnsted nanopure – ultra pure water system by
passing distilled water through a mixed bed of anion and cation exchange resins.
3.8.1
Standard Stock Solutions
Stock solutions of individual elements (Cr, Zn, Hg) of ultra high – purity grade
chemicals (99.99% pure) were obtained as 1000 µg/mL (ppm) solutions from Riedel de
Haen, Germany. The standard – 3 solution was purchased from Perkin Elmer local
supplier (K.L) and Mercury standard solution was purchased from Aldrich, USA. The
stock solutions were stored in Teflon bottles.
78
3.8.1.1 Standard Stock Solutions for ICP-MS and FI-MS
Standard – 3 solution supplied by Perkin Elmer was used for ICP-MS analysis and
single element of mercury standard was used for FI-MS analysis. The stock solutions were
stored in Teflon bottles. The following procedures were used for preparing standard stock
solutions. During the preparation of multi-element standard stock solutions, care must be
taken that the element were compatible and stable. Stock solutions of individual elements
would be checked for the presence of impurities, which might influence the accuracy of
the standard. Freshly prepared standards were transferred to acid cleaned, not previously
used FEP fluorocarbon bottles for storage and monitored periodically for stability. The
following combinations of elements were prepared.
Standard Solution - 3
Mercury Standard Solution
Aluminium
Manganese
Antimony
Molybdenum
Arsenic
Nickel
Beryllium
Selenium
Cadmium
Thallium
Chromium
Thorium
Cobalt
Uranium
Copper
Vanadium
Lead
Zinc
Mercury
Multi – element standard stock solution – 3 ( 1 mL = 10 µg) was prepared by
diluting 1 mL of each single element stock in the combination list to 100 mL with
deionized distilled water containing 1% (v/v) nitric acid.
3.8.1.2 Preparation of Calibration Standards
Fresh calibration standards (CAL solution) were prepared as needed. Each of the
standard stock solution was diluted to levels appropriate to the operating range of the
instrument using the appropriate acid diluent. The multi – element standard stock solution
– 3 was diluted to levels appropriate to the operating range of the instrument (ICP-MS)
using DDW containing 1% (v/v) nitric acid. The element concentrations in each
79
calibration solution should be sufficiently high to produce good measurement precision
and to accurately define the slope of the response curve. The instrument calibration was
initially verified using a quality control sample of Be, Mg, Co, Rh, Cs and Pb. Known
concentrations of standard solutions were used as a quality control sample to check up the
peak height or absorbance. If the peak height or absorbance of standard solutions were less
than 10 % of the calibration values, the samples were continued for analysis, otherwise
they were discarded and the instrument was again calibrated with standard solutions.
3.8.1.3 Blank Solutions
Two types of blanks were prepared for these methods. A calibration blank was
used to establish the analytical calibration curve and the laboratory reagent blank (LRB)
was used to assess possible contamination from the sample preparation procedure and to
assess spectral background. The rinse blank was used to flush the system between solution
changes for blanks, standards and samples. Sufficient rinse time was required to remove
traces of the previous sample. All diluted acids were prepared from concentrated acids
(concentrated nitric acid and hydrochloric acid) and DDW. Solutions would be aspirated
for 30 s prior to acquisition of data to allow equilibrium to be established.
3.8.1.4 Standard Stock Solutions for NAA
Single element stock solutions of Cr and Zn of ultra high–purity grade chemicals
(99.99% pure) were obtained as 1000 µg/mL (ppm) solutions from Riedel de Haen,
Germany were used for NAA as standard chemical solutions. Standards were prepared by
pipetting aliquots of 0.1 mg or 0.01 mg of standard solutions for each element onto a
cotton that was placed into clean snap-top (10 mm x 20 mm) polyethylene vials and heat
sealed.
80
3.9
Standard Reference Materials
A laboratory-working standard, prepared from or referenced to a primary standard
if possible, is used for regular instrument calibration. A ‘reference material’ (CRM) is
defined as a widely distributed material intended to be used for calibrating apparatus or
testing an analytical procedure. A ‘certified reference material’ (CRM) is a reference
material issued by a national or international organization, which certifies that its
composition is known within stated limits. Finally, a Standard Reference Material is a
CRM issued by organization like the U.S. National Institute of Standards and Technology.
To establish that an analytical procedure gives reproducible results is generally
easy. To ascertain that these reproducible results correspond to the true values is not easy.
Standardization of instruments with materials or known composition, which differ from
the matrix of the sample to be analysed, does not assure that true values are obtained. To
overcome the difficulties caused by matrix interferences with the analytical procedures
certified standards in various matrixes are needed. Such standard for total element
concentrations are available commercially.
Analysis of a reference material with recommended values for the concentrations
of the elements of interest is one of the most valuable ways of checking the validity of the
results coming from a laboratory. The recommended values for the concentrations
represent the accepted value, compiled from the data produced by a number of
laboratories. The most important criterion when choosing a reference material is that it
should be similar in nature to the samples to be analysed (Parry, 1991).
To provide quality assurance controls, standard reference materials having almost
similar matrix were used in all analysis. SRM 1572 (Citrus Leaves) was used for plant
analysis and SRM 1646 Estuarine Sediment supplied by the National Bureau of Standards
(NBS).) was used for sediment analysis. All SRM’s were subjected to the same treatment
and analysed as those of the samples to be able to be used in the comparative method of
analysis.
81
3.10
Sample Preparation
The aim of sample preparation is to reduce the sample size to allow a
representative sample to be chosen for analysis. Before analysis, samples may require
washing, drying (oven drying or freeze drying), homogenisation, fractionating or
pelletization. For samples of biological origin, freeze drying, also known as lyophilization,
is certainly the most appropriate method. It is generally accepted that this process does not
cause losses of any but the most volatile elements. The samples have to be pre-frozen
(e.g., at –30 oC or lower) prior to placement in the freeze drier, and that vacuum pump
must be able to obtain in short time an adequate vacuum. Generally any form of drying
may invalidate the sample for other experiments in which the chemical state is of interest,
such as organic extractable contents, nitrification rate, loss of enzymes, or change in
membranes (IAEA, 1990).
In general, the form of the sample is not important. It may be a solid, liquid,
powder, even a gas. However, the shape and size of the sample will affect the specific
activity induced on irradiation and counting and so it is important to be aware of the
problems that may occur. The range of possible sample sizes is a valuable feature of the
NAA technique and weighs from micrograms to hundreds of grams have been analyzed by
this method (Parry, 1991).
3.10.1 Preparation of Water Samples
Upon receiving the sample in the laboratory, sample pH adjustment was done for
the determination of acid-soluble metals, whereby the pH of the water sample must be
1.75 ± 0.1. Sample was allowed to come to room temperature, pH meter was calibrated
and the pH of the sample was measured in the container. Using deionised distilled water;
the electrode system was rinsed after each pH measurement. If the sample pH was above
1.85, (1+1) nitric acid was added in a drop wise manner, the sample was then mixed in the
container by inverting and shaking it and the pH was redetermined. Small increments of
the (1+1) nitric acid was continuously added and mixed until the sample is within the
desired pH range. If the pH should go below 1.65, (1+9) ammonium hydroxide was added
in a drop wise manner until the sample is within the pH range of 1.65 to 1.85.
82
For the determination of acid-soluble metals, the pH-adjusted sample is filtered
through 0.45-µm membrane filter. Because the sample solution to be filtered will be of
low pH (1.75 ± 0.1), the filter media may be either a polyvinyl chloride acrylic copolymer
or mixed esters of cellulose material. Before filtering any sample, the filtering apparatus
was made certain that it has been cleaned. Then, the filter support of the filtering apparatus
was inserted through the proper size rubber stopper and the stopper was wrapped with 1
inch PTFE laboratory tape to prevent contamination. The flask was then secured in an
upright position and the support was placed in the neck of the suction flask. The suction
flask was connected to the vacuum line. After that, the membrane filter was placed on the
filter support. The filter funnel was assembled to the support as recommended by the
manufacturer. The sample is not mixed, but decanted carefully approximately 50 mL of
sample from the container into the filtering funnel and vacuum is applied. After filtration
process, the vacuum is broken, the filtering apparatus is removed, the suction flask is
rinsed with the filtrate and discarded. When filtration is completed, the vacuum is broken,
the filtrate is transfered to a labelled, cleaned polyethylene storage bottle and stored until
all analysis have been completed. The above procedure was repeated until all samples and
quality control aliquots have been filtered. This sample can be used for ICP-MS and FIMS analysis directly.
3.10.1.1 Preparation of Water Samples for NAA Analysis
The filtered water samples were used to prepare for NAA analysis. Samples were
prepared by pipetting aliquots of 0.100 g to 0.130 g filtered water sample into 10mm x 20
mm (Fischer) snap-top polyethylene vials stuffed with cotton. Samples were prepared in
duplicates and the vials heat-sealed. Chemical standard solution comprising aliquots of Zn
and Cr was prepared in a vial and included in the batch for irradiation. Besides that, for
blank correction, an empty vial was prepared too. Each batch of water samples for
irradiation contains 18 vials inclusive of sample, standard and blank.
83
3.10.2 Preparation of Plant Samples
Collected plants were placed in plastic bags and transported immediately to the
laboratory. The plant samples were washed with tap water and well rinsed with deionised
water prior to analysis to remove surface contamination such as dust, soil particle and
dried leaves. Then it was cut into small pieces of 2 cm to 3 cm length using stainless steel
scissors and thoroughly mixed to obtain maximum homogenisation. Later on, the cleaned
plants were kept inside a plastic bag and stored in a freezer. They were then dried in a
freeze dryer at -80 0C at 0.2 bar for approximately 48 hours until their dry weights were
constant. After that, the dried samples were grounded using the swing grinder machine
and sieved to a particle size of 150 mesh. Finally, the ground powder was stored in
polyethylene bottles for further analyses
3.10.2.1 Preparation of Plant Samples for ICP-MS and FI-MS Analysis
The wet ashing technique implies heating the sample (organic or biological) in the
presence of a concentrated oxidizing mineral acid or mixture of acids. If the acids are
sufficiently oxidizing, the sample is heated strongly enough, and if the heating is
continued for a sufficient length of time, then it should be possible to oxidize most
samples completely, leaving various elements present in the acid solution in simple
inorganic forms suitable for analysis. Wet ashing by using concentrated HNO3 or mixture
of acids, is an extremely common and important method of decomposing organic and
biological samples. It is particularly useful for the determination of trace metals in various
types of sample, because by and large these are converted into simple involatile inorganic
cations, which remain in the acidic medium. But some elements such as Hg, As, Se, B and
Sb can be lost partially through volatility. Wet ashing is best for determination for metallic
elements. The technique is not difficult and no expensive apparatus is involved. It also
requires short period of time and many samples can be digested at a time. Limitations of
this technique are lost of elements through volatility. But not serious for metals except Hg
and non-metals may be lost this way.
84
The ashing of each sample was carried out for 2 hours with reflux. 5 mL nitric acid
and 5 mL deionised water were added to 25 ml round bottom flasks containing 0.200 g
samples with subsequent mixing. The round bottom flasks were covered with watch glass
to protect the sample from contamination. Samples were digested using round shaped
heating mantle at a minimum temperature of 120 0 C. Digestions were carried out in a
fume hood. The round bottom flasks were removed from the heating mantle and allowed
to cool to room temperature. The digest was then diluted to a final volume of 50 ml with
deionised water in a centrifuge tube. To avoid clogging problems with the ICP-MS, all
samples were centrifuged at 4000 rpm for five minutes to separate the undissolved
fractions in the sample digest. The resulting nitric acid solution is then ready for ICP-MS
and FI-MS analysis. Certified reference materials SRM 1572 (Citrus Leaves) and SRM
1646 Estuarine Sediment supplied by the National Bureau of Standards (NBS) were used
in the quality control and treated similarly.
3.10.2.2 Preparation of Plant Samples for NAA Analysis
In order to carry out neutron activation analysis, 0.200 g of plant sample was
placed into 10mm x 20 mm (Fischer) snap-top polyethylene vials. The samples were
prepared in duplicates and then heat sealed. A vial containing standard reference material
was included in the batch. The standard reference material used was NBS 1572 Citrus
Leaves. Aliquots of the appropriate single element chemical standard solution were also
irradiated along with samples in snap-top polyethylene vials. For blank correction, an
empty vial and duplicates of vial stuffed with cotton were prepared.
85
3.10.3 Preparation of Sediment Samples
The sediments were cleaned because it contained twigs and pebbles and air-dried in
a ventilated and shaded from sun condition for several days. It was mixed thoroughly to
ensure homogeneity. It was then stored in the freezer and dried in the freeze dryer until
their dry weights were constant (approximately 24 hr). The sediments were then ground
using swing grinding machine and sieved to 200 mesh particle size. Finally, the ground
powder was stored in polyethylene bottles for further analyses.
3.10.3.1 Preparation of Sediment Samples for ICP-MS and FI-MS Analysis
In the determination of the inorganic constituents of the sediment there are two
ways to look upon the analysis. If the concern is to determine the materials, which are
adsorbed on the mineral particles, then the analysis is carried out upon a solution made by
extracting the sediment with, for example, an acid. This does not dissolve the mineral
particles but is believed to solubilize the metal ions that are adsorbed upon them. The
rationale for this approach is that the concern is for those pollutants which have been
deposited in the sediment and which might be available for biological processes at the
sediment and water interface, rather than for the geochemical composition of the minerals
on the lake bed. If the concern is for a ‘total’ analysis, i.e. the chemical constitution of the
total sediment, it is necessary either to employ an analytical technique that uses solid
samples, or to solubilize all the minerals completely.
Digestions of sediment samples were carried out using nitric acid for two hours. 5
mL of nitric acid was added to 25 mL round bottom flask containing 0.200 g of sediment
sample and 5 mL deionised water. The round bottom flask was placed in a round shaped
heating mantle and the solution was refluxed at a temperature of 1200 C. The digest was
allowed to cool for 5 minutes and 2 mL of H2O2 (30 %) were then slowly added drop wise
to the digest until the effervescence stopped. Then it was allowed to stay at room
temperature overnight and watch glasses were used to cover to avoid contamination. The
digest was then topped up with deionised water and made up to 50 mL of volume in a
centrifuge tube. It was then centrifuged at 4000 rpm for 5 minutes to separate the
undissolved fractions from the dissolved fraction. The solution is now ready for ICP-MS
and FI-MS analysis.
86
3.10.3.2 Preparation of Sediment Samples for NAA Analysis
Samples between 0.100 g to 0.150 g were loaded into irradiation 10mm x 20 mm
(Fischer) snap-top polyethylene vials. The samples were prepared in duplicates and then
heat-sealed. A vial containing standard reference material with the same matrix as the
sediment samples was included in the batch. The standard reference material used was
NBS 1646 Estuarine Sediment. Aliquots of the appropriate single element chemical
standard solution were also irradiated along with samples in snap-top polyethylene vials.
For blank correction, an empty vial and duplicates of vial stuffed with cotton were
prepared.
3.11
Analysis Using ICP-MS
This work will describe a multi element analysis technique based on an
inductively coupled argon plasma mass spectrometric (ICP-MS) procedure. The distinct
advantage of this method over that previously reported elsewhere is the specific
optimisation of operating parameters for the simultaneous determination of elements and
use of realtime background corrections to reduce interference effects. A statistical
comparison with conventional analysis methods will be presented which illustrates the
relative accuracy of these methods of a routine analyses mode.
3.11.1 Summary of Method for ICP-MS
Sample material in the solution was introduced by pneumatic nebulization into
radio frequency plasma where energy transfers processes cause disolvation, atomisation
and ionisation. The ions were extracted from the plasma through a differentially pumped
vacuum interface and separated on the basis of their mass to charge ratio by a quadrupole
mass spectrometer having a minimum resolution capability of 1 amu peak width at 5%
peak height. A continuous dynode electron multiplier or Faraday detector and the ion
formation processed by a data handling system registered the ions transmitted through the
quadrupole. Interferences relating to the technique must be recognized and corrected. Such
corrections might include compensation for isobaric elemental interferences and
87
interferences from polyatomic ions derived from the plasma gas, reagents or sample
matrix.
3.11.2 Instrumentation for ICP-MS
Inductively coupled plasma mass spectrometer capable of scanning the mass range
of 5-250 amu (atomic mass unit) with a minimum resolution capability of 1 amu peak
width at 5% peak height was used in this work. The instrument was fitted with an
extended dynamic range system. The Perkin-Elmer SCIEX ELAN 6000 ICP-MS was
used in the analysis of water, plant and sediment from the river. The ELAN 6000 is the
latest generation of ICP-MS, which combines high sensitivities with each use and high
sample throughput. The ELAN 6000 ICP-MS is equipped with platinum sampling and
skimmer cones. A Gilson peristaltic pump from tubes arranged on a Perkin-Elmer As-90
auto sampler to a glass cyclonic spray chamber containing MEINHARD TR-30-C3
nebulizer pumps the samples. The resulting spray is delivered into the plasma with a
nebulizer argon gas flow of approximately 1 L/min. The instrument was mass calibrated
(tuned) with a 10ppb solution of Be, Mg, Co, Rh, Cs and Pb: peak resolutions were
adjusted to approximately 0.7 amu. Optimisation of analogue and pulse voltage, dual
detector calibration, and lens voltages auto-lens) were performed according to the
manufacturers specifications prior to each analytical run, instrument performance
characteristics were adjusted through changes in the nebulizer flow rate to results in the
daily performance net intensity mean ranges were flowed according to instruments
supplier. Supplied argon gas was highly pure (high-purity grade, 99.99%). A variablespeed peristaltic pump was used for solution delivery to the nebulizer. A mass-flow
controller on the nebulizer gas supply was used for flow control. A water-cooled spray
chamber was used to get benefits in reducing some types of interferences (e.g., from
polyatomic oxide species). In this work, we try to follow the recommended operating
conditions provided by the manufacturer and after verifying that the instrument
configuration and operating conditions satisfy the analytical requirements and to maintain
quality control data as verified instrument performance and analytical results. An electron
multiplier detector was being used, precautions would be taken, where necessary, to
prevent exposure to high ion flux. Otherwise changes in instrument responded to the
multiplier might result. The ICP-MS instrumentation is presented in Figure 3.2.
89
terminated, the source of the problem identified and corrected, the instrument recalibrated, and the new calibration was verified before continuing analyses.
Table 3.4 : Operating conditions of ICP-MS
ELAN 6000 Instrumental conditions and parameters
RF Power
1000 watts
Plasma gas flow
15 L/min
Auxiliary gas flow
1 L/min
Nebulizer gas flow
0.725 – 0.775 L/min
Solution pump rate
1.5 mL/min
Sample introduction system
Cross-flow with Scott spray chamber
Rinse time
35 seconds @ 48 rpm
Sample uptake time
25 seconds @ 48 rpm
Equilibrium time
10 seconds @ 24 rpm
Analysis time(total)
2.06 minutes
Detector mode
Dual mode
Lens
Lens scan enabled
Sampler/skimmer cones
Nickel
Scanning mode
Peak hopping
Number of points/peak
1
Dwell time
100 ms per point
Number of sweeps/reading
8
Number of reading
1
Number of replicates
3
Total time
3.16 minutes
3.11.5 Standardization and Calibration
Demonstration and documentation of acceptable initial calibration was required
before any samples are analysed and is required periodically throughout sample analysis
as dictated by results of continuing calibration checks. The instrument was calibrated for
the analyte to be determined using the calibration blank and calibration of standards
prepared at four concentration levels within the linear dynamic range of analyte.
90
3.11.6 Experimental (Instrumentation of FI-ICP-MS)
An ELAN 6000 (Perkin-Elmer SCIEX, USA) ICP-MS instrument was used for all
analyses. For vapour introduction, the ICP torch was fitted with a standard vapour adapter.
For solution introduction, and to optimise the alignment of the torch, a gem tipped
chemically resistant Ryton cross-flow nebulizer and a Ryton spray chamber were used.
Table 3.5 summarises the operating conditions.
3.11.7 Data Acquisition and Processing
In the ELAN software, data acquisition parameters are entered via the parameter
entry form and Table 3.5 shows the parameters used. The elements to be determined are
specified and the integration time and dwell time is also entered in this form. Peak area
was used to characterize analytical response in these studies, because this processing mode
provided better precision.
3.11.8 Flow Injection System
A FI-MS 100 with an AS- 90/91 random access auto sampler (Perkin-Elmer, USA)
was used. The flow injection system consists of two peristaltic pumps, an injection valve
and the required tubing and is fully controlled by the ELAN-FIMS spectrometer software
through a computer (IBM PS/2 Model 70). Operating parameters, such as pump speed,
injection system are entered in a FI- MS program. The gas liquid separator is made of
chemically resistant plastic and contains an exchangeable PTFE membrane filter. The
manifold used in this study is shown in Figure 3.3.
91
Table 3.5 : Operating conditions used for the ELAN 6000 FI-ICP-MS Instrument
Forward Rf power
1000 W
Plasma argon flow rate
1.51 min -1
Auxiliary argon flow rate
0.81 min -1
Carrier argon flow rate
1.01 min -1
Sampler and skimmer cones
Platinum
Data acquisition
MCA transient
Scan mode
Peak hopping
Points per spectral peak
1
Dwell time
50 ms
Scan mode
Peak-hope transient
Sweeps per reading
2
Signal processing
Spectral peak integrated; signal profile
conted
Resolution
0.8 at 10% peak maximum
Number of replicates
3
92
Figure 3.3
Schematic diagram of FI-MS
3.11.9 Hydride Generation System Conditions
In this work, a continuous flow in situ nebulizer/ Hg sample introduction system
was coupled with ICP-MS for Hg determination with FI analysis. The operating
conditions for the Hg were optimised by the FI method. In this study, a solution containing
1 ng mL -1 Hg(II) in 0.5% K2Cr2O7 and 0.1 M HNO3 was selected as the model to optimise
the operating conditions of the HG system. This solution was loaded in the injection loop
and injected into the hydride generation (HG) system.
93
3.11.10 Post-run Step
The pump-2 (in Figure 3.3) is operated continuously at a moderate rate of 50 rev
min –1 to rinse the sample tubing from the AS 90/91 autosampler to the valve with a wash
solution. Pump-1 is also set to run continuously to remove the wash liquid from the gasliquid separator.
3.11.11 Standardization by FI-MS
Before the samples were analysed, a calibration exercise would be performed
using a minimum of four standard solutions that bracket the anticipated concentration
range of the samples. Calibration standards would be prepared from the stock standard
solution by appropriate dilution with deionised distilled water in volumetric flasks. A
calibration curve of analyte{Hg(II) by FI-MS} response peak area versus analyte
concentration was constructed. The coefficient of correlation for the curve would be 0.99
or greater.
3.12
Analysis Using Neutron Activation Analysis
All irradiations have been carried out using the facilities at the Malaysian Institute
of Nuclear Technology Research (MINT). Irradiations were performed in a neutron flux of
3x 1012 n cm-2 s-1 for 6 hours at 750 kW power from a TRIGA Mk II reactor using the
rotary rack facility. This was followed by 20 days of cooling period for determination of
elements Cr and Zn.
94
3.12.1
Measurement of Activities of NAA
The gamma ray activities of the samples were measured by a high-resolution
gamma spectrometer consisting of a large volume coaxial ORTEC HPGe detector with a
resolution of 1.8 keV at 1332 keV 60 Co and relative efficiency of 20%. The counting for
the gamma ray activities were done over a period of 1800 seconds- 3600 seconds.
Amplification and analysis of signals were done using an ORTEC 472A spectroscopy
Amplifier and Nuclear Data ND 66 Multi Channel Analyzer calibrated at 0.5 keV per
channel. Dedicated PDP 11 computer connected to the system carried out peak
identification and quantitation. Chromium was analysed via the 320.23 keV of Cr-51.
While, zinc was analysed via the 1115.5 keV photopeak of Zn-65. The precision and
accuracy of the analytical technique NAA for Cr and Zn were evaluated by analysing
standard reference materials from NBS 1646 Estuarine Sediment and NBS 1572 Citrus
Leaves.
3.12.2
Detection Limits of NAA
Detection limits is defined as for NAA difference between certified value and
obtained value and this value was divided by these two values square root value. Detection
limit can be calculated as:
Detection Limit (Z) = | X1-X2 |
r12 – r22
Where, X1= SRM (Estuarine Sediment) value, X2 = obtained value, r1 = standard
of SRM and r2 = standard of obtained value. If the detection limit (Z) obtained was less
than 2, i.e.: Z<2 but greater than 0 is acceptable and it is very good. If the detection limit,
Z value becomes greater than 2 or equivalent to 2 then it is not acceptable.
CHAPTER 4
RESULTS AND DISCUSSION
4.0
Introduction
Samplings during the duration of the study proceeded successfully and no major
problems were encountered. This chapter explains and discusses results of six samplings
that spanned almost a year for analysis of water quality parameters and heavy metals in
water, sediment and plant of the Sg. Skudai taken at 16 sampling locations. The samples
were analyzed using ICP-MS and NAA techniques in the Malaysian Institute of Nuclear
Technology (MINT), Bangi, Selangor for elemental concentration. While, the water quality
analyses were carried out in the Environmental Engineering Laboratory (Faculty of Civil
Engineering), Radiochemistry Laboratory (Faculty of Science) and some parameters were
measured in-situ. The discussion includes determination of the river water quality using a
number of parameters and to compare it with the DOE Interim National Water Quality
Guidelines for Malaysia (INWQS) and also determination of heavy metals in plants
(Phragmites karka) and sediments from the river and to compare it with the DOE Water
Quality Criteria and Standards for Malaysia. Besides that, the trend of several pollutants in
the river and the statistical analysis of the results obtained after analyses were performed
are also discussed. In addition to this, correlation studies on the effect of the pollutants to
the river system and its aquatic habitats were done to determine the relationship between
the variables.
96
4.1
Water Quality Parameters Analysis
The physico-chemical parameters of the water column such as DO, pH,
temperature, BOD and COD are important because they have a significant effect on the
water quality. Furthermore, aquatic life will also suffer due to degradation of river water
quality and rivers will be unsuitable for supporting healthy aquatic life. Thus, it is
important that the physico-chemical parameters of a river have to be studied. As for the
water quality studies, water samples were taken for laboratory tests and also done in-situ to
get the existing environmental information. Results of each sampling is presented in
Appendix 1.The overall water quality results and the average water quality results at the
sixteen sampling points after six samplings for the Sg. Skudai is as in Table 4.0 and Table
4.1. The water quality results were then compared with the DOE Interim National Water
Quality Standards for Malaysia as in Appendix 2.
4.1.1
Temperature
The temperature of water is one of the most important characteristics that
determines, to a considerable extent, the trends and tendencies of changes in the river water
quality. Increased water temperature decreases the solubility of dissolved oxygen and
water temperatures above 27 0C are “unsuitable” for public use. At above 32 0C it would
be considered “unfit” for public use (Chapman, 1992). Temperature plays a vital part in
chemical and biochemical reactions and is an important factor influencing self-purification
in streams. The metabolic rate of aquatic organisms is related to water temperature, and in
warm waters, respiration rates increase leading to increase oxygen consumption. Growth
rate will also increases. This can lead to increased decomposition of organic matter, water
turbidity, macrophyte growth and algal blooms, especially when nutrient conditions are
suitable (Jackson and Jackson, 1996). Toxic chemicals made more soluble by higher
temperature may present an additional hazard to the organisms in the water (USEPA,
1986). Higher temperature increases the toxicity of many substances such as heavy metals
or pesticides, whilst the sensitivity of the organisms to toxic substances also increases.
Increase in water temperature causes a decrease in oxygen solubility, an increase in the rate
of biochemical oxygen demand (BOD) and in nitrification process. As a result, there may
be oxygen deficiency and capacity of the receiving waters to assimilate waste is reduced.
97
There was no significant difference in temperature measured along the river.
Temperature variation was found to be low. The mean value of temperature measured
along the rivers of Sg. Skudai basin ranged from 26.5 0C to 29.6 0C (Table 4.0). The lowest
level was recorded from the upstream of Sg. Skudai at sampling point 1.
Table 4.0 : Results of water quality analysis
Sampling
Point
pH
Temperature
(0C)
DO
(mg/L)
BOD
(mg/L )
COD
(mg/L )
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
6.24 ±0.56
5.83± 0.43
6.33± 0.22
6.31± 0.48
5.91± 0.71
6.23 ±0.49
6.09± 0.78
5.67± 0.74
6.00± 0.78
6.11± 0.62
5.26± 1.23
5.89± 0.75
6.64± 1.07
7.15± 1.21
6.79± 0.89
7.13± 0.65
26.6 ± 2.01
27.2 ± 1.63
28.1 ± 1.28
28.5 ± 1.15
28.4 ± 1.08
29.6 ± 1.01
29.0 ± 1.57
29.1 ± 1.45
29.4 ±1.83
28.6 ± 1.45
29.6 ±2.47
29.3 ± 2.41
29.6 ± 1.63
29.2 ± 2.34
29.3 ± 1.92
28.8 ± 2.02
6.49± 0.81
5.19 ±1.07
5.63± 0.87
5.35± 0.73
5.20± 0.44
5.48± 0.69
5.01± 0.57
3.82± 0.60
4.44± 0.58
5.27± 0.34
4.36± 0.39
4.71± 0.54
4.98± 0.32
4.35± 0.49
4.18±0.96
5.46± 0.64
2.47± 0.66
4.37± 1.17
3.67± 1.04
3.78 ±0.92
4.22 ±0.96
4.10 ±0.85
5.00 ±0.49
6.73 ±1.55
5.88 ±0.76
5.08 ±0.84
6.40 ±1.21
5.88 ±0.88
5.20 ±1.48
6.02 ±0.73
6.48 ±1.12
4.53 ±0.97
30.5 ± 11.3
42.8 ± 13.3
37.7 ± 14.2
40.5 ± 17.5
57.0 ± 14.8
52.3 ± 11.5
51.7 ± 22.2
66.8 ± 16.6
62.0 ± 19.7
52.8 ± 16.4
93.0 ± 31.8
81.5 ± 25.7
57.0 ± 24.3
79.5 ± 40.1
82.3 ± 44.5
42.8 ± 18.6
Table 4.1: Overall average water quality results for the Sg. Skudai river system
pH
Mean
S.D
C.V(%)
6.22
0.51
8.20
Temperature
(0C)
28.8
0.86
3.00
DO
(mg/L)
4.99
0.66
13.3
BOD
(mg/L)
4.98
1.19
24.0
COD
(mg/L)
58.1
18.2
31.3
(Kg. Melayu Sedenak) and the highest at sampling point 6 (PUB, Skudai) and 13 (Kg.
Pangkalan Rinting). In the upstream reaches of the Sg. Skudai , lower water temperatures
were recorded as the stretches were covered with oil palm plantation. Higher temperatures
were recorded in the downstream reaches where tree cover is less and it is a highly
industrialized and populated area. Previous studies of Sg. Kelang, Sg. Gombak and Sg.
Selangor in the Klang Valley reported that the temperature recorded generally range from
98
24.0 0C to 31.3 0C (UKM - DOE, 2000). River water temperature also varies between 26.0
0
C – 30.0 0C during the day and between 20.0 0C to 28.0 0C during the night (DOE, 1986).
The mean temperature of the Sg. Skudai is 28.7 0C (Table 4.1). Temperature values of all
the sampling points were within the Interim National Water Quality Standards for
Malaysia (INWQS) threshold level for the support of aquatic life and supply water for
potable, industrial and agricultural uses (Appendix 2). The temperature range noted for the
Sg. Skudai is normal for the Malaysian river water temperature. In a previous study of Sg.
Skudai, the temperature that was recorded ranged from 27 0C to 29 0C ( Jeffree Mohamed,
1993).
4.1.2
pH
pH plays a critical role in the chemistry of rivers. A fall in pH may allow the
release of toxic metals that would otherwise be absorbed to sediment and essentially
removed from the water system. A decrease in pH would increase metal availability,
lending itself to greater uptake by organisms and can cause physiological damage to
aquatic life (Connell and Miller, 1984). Surface waters normally have pH values between
6.5 – 8.5, and only rarely are outside the range of 4 - 9. River water is usually more
alkaline because the presence of carbonates and hydrogen carbonates. Surface water has
lower buffering capacity and consequently the pH of surface water is more changeable.
The pH of water has an important influence of living organisms and on any use of the
water. In water too acidic and too alkaline, there is very limited aquatic life. The acid
waters are especially detrimental to the water supply system. The acidification of surface
water accelerates the leaching out of heavy metals and radionuclides from the bottom
sediments.
The pH level is a measure of the hydrogen ion in the water. Since the pH value is
determined by the interaction of numerous substances contained in water, including those
that are chemically and biochemically unstable, it must be determined shortly after the
sample has been taken; the sample cannot be preserved for later analysis. For both the
freshwater and estuarine, rapid pH fluctuations are due to pollutant discharges (DOE,
1986). The highest pH level recorded along the Sg. Skudai is 7.15 at sampling point 14
(Kg.Tlk. Serdang) and the lowest ph level is 5.26 at sampling point 11 (Tampoi) (Table
4.0). Elsewhere, pH recorded from Sg. Selangor, Sg. Kelang and Sg. Gombak ranged from
4.9 to 8.3 (UKM-DOE, 2000). Previous study of Sg. Skudai reported pH ranging from 6.0
99
to 8.2 and also that the pH at the river mouth was higher compared to the pH at the
locations upstream (Jeffree Mohamed, 1993). The pH for this study too is higher at the
river mouth compared to other location upstream.
The mean pH value for Sg. Skudai is found to be 6.2 (Table 4.1). The average level
of the range of pH measured of almost a year sampling from all the sampling stations along
the Sg. Skudai were within the INWQS threshold range for all classes (Appendix 2). In
terms of average pH levels, water of the Sg. Skudai river system is still suitable for the
support of healthy aquatic life. The higher level of pH of river waters is attributed to
industrial pollutant from the surrounding area and low pH values are due to high organic
content in river water (Sarmani, 1985). Low pH at Tampoi was attributed to the presence
of high organic matter resulting from the discharge of organic matter into the river from
the food processing industries functioning nearby the river. Whereas, the high pH level at
Kg. Tlk. Serdang was a result of discharge from a number of printing and electronic
factory effluents containing acid from the highly industrial area.
4.1.3
Dissolved Oxygen (DO)
The content of oxygen is an important indicator of the pollution of a water body.
DO depend on several factors, some of which are the amount of rainfall, saltiness of the
water, the amount of decomposition in the water, the amount of plant life in the water, type
of rock in riverbed and presence of pollutants. The study of the oxygen content plays quite
an important role, when evaluating the conditions of the habitation in a water body. In
order to maintain an aerobic condition, raw water should contain not less than 2 mg/L of
dissolved oxygen in water. From the viewpoint of living organisms, no gas is more
important than oxygen. Because all heterotrophs use oxygen for their respiration, it tends
to be removed continuously from water. The only means by which it can enter the water
are through solution at the air-water interface or through photosynthesis by aquatic plants.
The high level of animal activity, coupled with an active detritus food chain, can withdraw
a large amount of oxygen from the water. In addition, the low level of turbulence means
that less oxygen is incorporated into the water at the surface. Supersaturated concentration
of dissolved oxygen may cause an increased rate of corrosion of metal surfaces in both the
water treatment facilities and in the water distributing system, levels of dissolved oxygen
with concentrations greater than 8 mg/L are usually not recommended for raw water
supply (DOE, 1986).
100
The average levels of DO obtained along the Sg. Skudai river system ranged from
3.82 mg/L at sampling point 8 (Tmn. Universiti) to 6.49 mg/L at sampling point 1 (Kg.
Melayu Sedenak) as shown in Figure 4.0. Meanwhile, the mean DO obtained for Sg.
Skudai was found to be 4.99 mg/L (Table 4.1). Previous studies indicated that dissolved
oxygen recorded from Malaysian river waters has been known to range from 0.80 to 8.80
mg/L (Bishop, 1971, Environmental Protection Society, Selangor, 1975). DO levels at
Tmn. Universiti (8), Gelang Patah (9), Tampoi (11), Kg. Skudai Kiri (12), Kg. Pangkalan
Rinting (13), Kg. Tlk. Serdang (14) and Pulai (15) exceeded the INWQS threshold range
for classes 1, 11A and 11B (Appendix 2). While, other sampling points of this river
showed DO values within the INWQS threshold level for the support of aquatic life (class
11A and 11B). Salty waters contain less dissolved oxygen than streams and lakes and
suffer natural oxygen depletion. This can be observed at Kg. Skudai Kiri (12), Kg.
Pangkalan Rinting (13), Kg. Tlk. Serdang (14) and Pulai (15), which are located near the
estuary and river mouth. Meanwhile a low level of dissolved oxygen (DO) is also
attributed to discharge of organic matter into the river from the sewage treatment plant,
industries and agriculture (Gomez, 1999) as observed at Tmn. Universiti (8), Gelang Patah
(9) and Tampoi (11) that are located at major industrial areas. DO levels of 3.05 to 7.11
mg/L were recorded in Sg. Sepang Kecil (Baktini Sawawi, 1999). This clearly shows that
the DO levels of Sg. Skudai are still in the normal range when compared with other
Malaysian rivers. On the contrary, a recent study of the DOE (2003b), reported that low
DO was observed at Sg. Kelang, Sg. Perai and Sg. Putat due to sewage or latex based
industries. This would affect the river water quality and the aquatic ecosystem.
4.1.4
Biological Oxygen Demand (BOD)
The biochemical oxygen demand (BOD) of waters and wastewaters is the amount
of molecular oxygen required to stabilize the decomposable organic matter present in water
by aerobic biochemical action. The dissolved oxygen level in water is greatly affected by
the content of biochemical oxygen demand. Elevated organic matter in river waters
increases the biochemical oxygen demand (BOD) to oxidize the organic matter. BOD is
the rate at which bacteria and other microorganism use dissolved oxygen to decompose
organic matter. BOD levels are used as indicators of organic pollution in water quality
monitoring (Law, 1981). A low BOD reading means either that the water is clean or that
the organisms have been killed by toxic pollutants. Maheswaran (1984) has shown that 53
% of the BOD loadings are generated from palm oil industry (DOE, 1986).
101
From Table 4.1, we found the mean BOD value for the river is 4.98 mg/L. The
average levels of BOD measured from Malaysian rivers in previous studies ranged from
1.1 to 676.00 mg/L (Bishop, 1971, Law, 1980, UKM-DOE, 2000). In this work, it was also
found that the average levels of BOD obtained along the Sg. Skudai ranged from 2.47
mg/L (Kg. Melayu Sedenak) to 6.73 mg/L (Tmn. Universiti) as depicted in Figure 4.1. For
all the sampling points, the BOD levels of the Sg. Skudai exceeded the INWQS threshold
level for classes I, IIA, IIB and was within the INWQS threshold range for aquatic life
protection and for livestock drinking that should be revised according to the local
environment conditions purpose (Class III) (Appendix 2).High BOD levels were observed
at sampling point 8 (Tmn. Universiti), 11 (Tampoi), 14 (Kg. Teluk Serdang) and sampling
point 15 (Pulai) indicating a good deal of high oxygen demanding organic matter was
present to be decomposed due to the discharge from industrial areas, sewage treatment
plant, housing and urban areas. While, the upper reaches of the stream recorded a lower
BOD value because it is a less populated area and there is absence of industrial activity
there. Discharge of high oxygen demanding organic substances in the lower reaches of the
Sg. Skudai due to industrial activities will further deteriorate river water quality and rivers
will be unsuitable for the support of aquatic life and other water uses. Meanwhile, previous
study conducted in Sg. Segget, Johor reported BOD levels of 50 mg/L to 5 mg/L (Kadir
Jaafar, 2002). Therefore the BOD levels of the Sg. Segget, Johor is higher than the BOD
Dissolved Oxygen (mg/L)
levels observed at the Sg. Skudai river system.
7
I
6
II
5
III
4
3
IV
2
1
V
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
Sampling Points
INWQS class
Figure 4.0
Average dissolved oxygen values for 16 sampling points along the
down stream route of the Sg. Skudai river system
102
Biological Oxygen Demand
(mg/L)
7
6
III
5
4
II
3
2
I
1
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
Sampling Points
INWQS class
Figure 4.1
Average biological oxygen demand values for 16 sampling points
along the downstream route of the Sg. Skudai river system
4.1.5
Chemical Oxygen Demand (COD)
Chemical oxygen demand (COD) is a test of oxygen demand in which the organic
matter is chemically oxidized instead of being biologically oxidized. COD values are
higher than BOD values because this chemical test oxidizes all of the organics present in
the water samples, while the BOD test which is a biological test is selective to organisms
and microorganisms present in the water samples (Greenberg et al., 1979). Elevated
organic matter in river waters increases the chemical oxygen demand to decompose
chemicals. Increased COD levels in river waters was attributed to the increase of organic
matter and inorganic chemicals in river waters from agriculture, urban run-off and
industrial discharge (Wandan and Zabik, 1996)
For all the samples analysed for COD, Table 4.0 shows the highest level of COD
level at sampling point (11) Tampoi, (12) Kg. Skudai Kiri, (15) Pulai, and lowest at (1) Kg.
Melayu Sedenak and (3) Tmn. Mewah compared to other stations. The average levels of
COD along the Sg. Skudai river system ranged from 30.5 mg/L to 93.00 mg/L as depicted
in Figure 4.2. Elsewhere, it was reported that the average levels of COD from the
Malaysian river waters ranges from 2.1 mg/L to 2418 mg/L (Bishop, 1971, Environmental
Protection Society, Selangor, 1975; UKM-DOE, 2000).
103
On the whole, the mean of COD from the Sg. Skudai river system is 58.14 mg/L
(Table 4.1). This does not comply with the INWQS recommended threshold level of COD
for Malaysian rivers (classes I, IIA, IIB), but is within the threshold level for class III and
above (Appendix 2). The COD levels obtained from the Sg. Skudai river system were
higher than the INWQS threshold level for Classes I, IIA and IIB for all sampling points
and below the INWQS threshold range for classes III and IV, namely at Kg. Melayu
Sedenak (1), Sengkang (2), Taman. Mewah (3), Kg. Pertanian (4) and Kg. Sg. Danga (16).
Very high level of COD was observed at the sampling points 5 to 15 due to the excessive
discharge of organic matter and inorganic chemicals from agriculture, urban areas and
industries from the surroundings into these rivers. A number of authors reported that the
upstream stretches of Malaysian rivers are not polluted by high oxygen demanding organic
matter, while the middle and downstream stretches of the river are usually highly polluted
(Aziz, 1983; Wandan and Zabik, 1996; Erdawati, 1997). This situation too can be observed
in the Sg. Skudai river system. In terms of COD, the Sg. Skudai river system is still
unsuitable for the support of aquatic life and other water uses. A recent study, conducted in
the Sg. Segget reported that the COD levels were ranging from 134 mg/L to 20 mg/L.
When compared to the Sg. Skudai COD levels, the COD levels in Sg. Segget is higher
(Kadir Jaafar, 2002).
IV
IV
Chemical Oxygen Demand (mg/L)
100
90
80
70
60
III
50
40
30
II
20
I
10
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
Sampling Points
INWQS class
Figure 4.2
Average chemical oxygen demand values for 16 sampling points along
the downstream route of the Sg. Skudai river system
104
4.2 Analysis of Standard Reference Materials
In the case of neutron activation analysis, the samples were irradiated in powder
form. Whereas, for determination of metals in solid samples using ICP-MS analysis, the
transformation of the solid samples into solution is still a very important step. For this
purpose, several decomposition procedures have been recommended, depending on the
kind of sample, the sample size and the elements of interest. The preparations of plant and
sediment reference materials were discussed in sections 3.10.2.1 and 3.10.3. Standard
Reference Materials are commonly used for assessing analytical accuracy. Tests of
accuracy is performed on a plant standard reference material, SRM 1572 (Citrus Leaves)
obtained from the National Institute of Standards and Technology (NIST) and one
sediment standard reference material, SRM 1646 (Estuarine Sediment) also obtained from
NIST. Data of these standard reference materials are shown in Appendix 3. These
materials were chosen because they match the matrix of the samples and the elements of
interest in this study.
The accuracy of the method is determined by calculating the percentage of analyte
recovery from the analytical procedures. The analytical results for these SRMs are given in
Table. 4.2 (i) and Table 4.2 (ii). The correlation coefficient R2 calculated between the
calculated and the certified values of the reference material for Citrus Leaves (R2 = 0.9863)
and Estuarine Sediment (R2 = 0.9361) shows a very good correlation exists. Thus, the
results of these digestions indicate a good agreement between our data and the reference
values. Errors of measured values were less than 20 % of the certified values for all
elements in the plant reference material and the sediment reference materials.
Discrepancies between found and certified values were also observed in plant reference
materials and in sediment reference materials. The lower recoveries were probably caused
by incomplete analyte recovery from the plant and sediment matrix. Incomplete analyte
recoveries in plant matrix may be caused by the presence of siliceous materials in the
reference material (Rodushkin et al., 1999). Hence, Zn with the half life of 243.9 days in
plant samples was determined using the neutron activation analysis for a better recovery
and relative standard deviation. This was possible due to the duration of the longer half
life; samples that were irradiated could be brought back for counting purposes. If the
element has a shorter half life, counting had to be done in (MINT), this was a problem due
to the high number of samples involved in the analysis. While, the concentrations of Cr
and Cd in sediment were found to be lower than reference values as a result of incomplete
dissolution of refractory minerals such as chromite (Marin et al., 1997). With the reagents
105
used in this study, it is impossible to dissolve such material completely. Hence, the
recovery of some elements such as Cr and Cd that are associated with resistant fractions of
the material will strongly depend on digestion conditions (Lo and Fung, 1991). Due to the
high number of samples for analysis and considering the time and cost factor, Cd could not
be determined using the neutron activation technique, while chromium was possible to be
determined using the neutron activation technique because of its longer half life (27.7
days). Therefore, Cd was not considered in the determination of heavy metals in the
sediment samples from the Sg. Skudai river because of its shorter half life of 53.46 hours.
Table 4.2(i) : Analytical results for elements in NIST-SRM 1572 Citrus Leaves.
Values are given in ppm (µg/g) and correspond to the average and Stddev (relative standard
deviation) (n = 3)
Citrus
Leaves
(R2=0.9863)
Calculated
mean
(µg/g)
SD
Certified
value
(µg/g)
Recovery
(%)
Cr
Ni
Cu
Zn
As
Cd
Pb
Hg
0.74
1.10
15.61
28.73
3.15
0.03
10.70
0.12
2.15
0.22
7.40
6.25
0.99
0.03
4.44
0.17
0.80
0.60
16.50
29.00
3.10
0.03
13.30
0.08
92.5
183.3
94.6
99.06
101.6
100.0
83.0
150.0
Table 4.2 (ii) : Analytical results for elements in NIST-SRM 1646 Estuarine Sediment.
Values are given in ppm (µg/g) and correspond to the average and Stddev (relative standard
deviation) (n=3)
Estuarine
Sediment
(R2=0.9361)
Calculated
mean
(µg/g)
SD
Certified
value
(µg/g)
Recovery
(%)
Cr
Ni
Cu
Zn
64.44
33.00
18.28
13.99
0.88
76.00
85.0
As
Pb
Hg
181.88 13.31
27.17
0.07
0.57
4.72
1.00
0.75
32.30
18.00
138.00 11.60
28.20
0.06
102.2
101.5
131.8
96.3
116.7
0.63
114.7
106
4.3 Precision and Accuracy
The accuracy of the overall analytical procedures was estimated by the analysis of
certified reference materials. Among elements for which certified concentrations are
available, good agreement between measured and reference values were found for the
element of interest in the digestion procedure. Another means of confirming the accuracy
of the results was to analyse a known concentration standard solution or Quality Control
Standard Solutions (QCSS). The verified results were placed in Table 4.3. The precision or
the reproducibility of the analytical instrument was assessed from replicate analysis,
including sample preparation of reference material and was found to be 1.11 % - 33.47 %
RSD as listed in Table 4.4. Instrument operating conditions were summarized in Table 3.3
and detection limits were determined using the procedure described in Section 3.11.7. The
detection limits were found to be controlled by digestion blank levels in ICP-MS and given
in Table 4.5. Analytical results below detection limit are not reported. As for neutron
activation analysis, the precision and the reproducibility of the analytical instrument were
assessed with the continuous irradiation of the SRM samples in every batch for the
irradiation of the plant samples. The results as shown in Table 4.6 (i) indicates a very good
analyte recovery for Zn in plants and the calculated relative standard deviations was not
more than 7 %. The result of chromium for each batch is shown in Table 4.6 (ii). The
results indicate a good recovery percentage of 85 % and standard deviation not more than
14 %, thus chromium in sediment is suitable to be analysed using the activation analysis.
The SRM samples result using ICP-MS and NAA techniques are shown in Appendix 4.
As for the higher SD compared to the mean for analysis of NIST 1572 Citrus
Leaves for Cr, Hg in Table 4.2 (i) and NIST 1646 Estuarine Sediment in Table 4.2 (ii) for
Hg, shows that some of the SRM results were too high and some were too low compared to
the certified value for each replicate. This is due to some errors during digestion, handling
and analysis of the SRM samples. Random errors, such as the apparatus used for the lab
digestion procedure were less clean, procedures while transferring the solution and
centrifuging the solution could also cause contamination and loss of analyte. Besides that,
systematic errors such as minor interference of the instrument during analysis could also
contribute to this factor. Also, the percentage of recovery of certain elements was too high
due to element contamination during analysis. This problem could be rectified if an
analytical technique that does not require sample dissolution is used, for example laser
ablation or if more replicates were used to calculate the percentage of recovery. In this
study, these measures were not done due to time and cost constraint, because the
107
instrument that was used in this study was in MINT, Bangi and far from UTM, Skudai.
Moreover, the number of samples that was allowed to be analysed each time in MINT were
controlled due to a large number of samples that were received from other institution for
analysis.
108
Table 4.3 : Quality control standard sample solution results of ICP-MS
Analyte
QCSS
QC calculated
Std Dev.
Recovery (%)
value
Hg
Cr
Ni
Cu
Zn
As
1 ppb
0.92 ppb
0.09
92.4
5 ppb
4.52 ppb
0.33
90.4
5 ppb
4.16 ppb
0.33
83.2
10 ppb
10.25 ppb
0.08
102.5
30 ppb
30.50 ppb
0.22
101.5
50 ppb
50.40 ppb
0.69
100.1
100 ppb
98.12 ppb
1.49
98.1
10 ppb
9.80 ppb
0.05
97.8
30 ppb
30.20 ppb
0.10
100.1
50 ppb
50.26 ppb
0.38
100.5
100 ppb
99.67 ppb
1.06
99.7
10 ppb
9.86 ppb
0.07
98.6
30 ppb
37.13 ppb
0.13
123.8
50 ppb
44.98 ppb
0.58
89.9
100 ppb
89.53 ppb
0.28
89.5
10 ppb
7.10 ppb
0.07
71.0
30 ppb
37.54 ppb
0.51
125.1
50 ppb
39.31 ppb
0.76
78.6
100 ppb
84.21 ppb
0.49
84.2
10 ppb
9.79 ppb
0.12
97.9
30 ppb
29.80 ppb
0.21
99.3
50 ppb
49.92 ppb
0.66
99.8
100 ppb
98.06 ppb
0.11
98.0
109
Table 4.3 contd/-
Cd
Pb
10 ppb
9.82 ppb
0.12
98.2
30 ppb
29.63 ppb
0.10
98.8
50 ppb
49.92 ppb
0.66
99.8
100 ppb
96.67 ppb
0.32
96.7
10 ppb
10.65 ppb
0.11
106.5
30 ppb
26.93 ppb
0.13
89.8
50 ppb
48.54 ppb
0.17
97.1
100 ppb
98.30 ppb
0.60
98.3
Table 4.4 : Analytical results of replicate analysis of standard reference material NISTSRM 1572 Citrus Leaves.
Analyte
Hg
Concentration of
replicates (µg/L)
6.34
6.80
6.77
SD
0.25
Average
(µg/L)
6.639
RSD(%)
3.8
Cr
0.63
0.54
0.47
0.08
0.55
14.3
Ni
0.17
0.28
0.35
0.09
0.27
33.4
Cu
7.05
6.94
7.09
0.07
7.02
1.1
Zn
2.66
3.34
4.94
1.17
3.65
32.1
As
1.61
1.59
0.16
1.69
9.3
110
Table 4.4 Contd/-
1.87
Cd
0.02
0.02
0.02
0.05
0.02
3.1
Pb
6.10
5.94
6.29
0.17
6.11
2.8
Table 4.5 : Estimated instrument detection limits and calculated detection limits
Element
Recommended
mass
Cr
Ni
52
58
60
Cu
Zn
As
Cd
Pb
63
64
75
112
114
208
Estimated
IDL
(µgL-)
0.02
0.05
0.05
0.02
Calculated
IDL
(µgL-)
2.50
0.36
0.13
0.13
0.5
6.34
0.1
0.01
0.01
0.003
0.10
0.02
0.02
0.29
Interference
40
Ar-12C
40
Ar-18O
44
Ca-16O
40
Ar-23Na
64
Ni-(093),32S2
46
Ar-35Cl
111
Table 4.6(i) : Results of concentration of Zn in NIST-SRM 1572 Citrus Leaves for every
batch of NAA irradiation (recovery %).
Batch (Date)
1
(27/9/2001)
2
(24/10/2001)
3
(24/10/2001)
4
(6/2/2002)
5
(6/2/2002)
6
(7/2/2002)
7
(7/2/2002)
Average
Analyte (Zn in ppm)
24.56±1.24
28.34±0.98
29.93±1.78
23.00±2.02
23.30±1.43
40.50±0.92
31.86±1.25
28.73±6.25
Recovery %
84.72
97.72
103.21
80.00
80.34
139.66
109.86
99.06
Table 4.6(ii) : Results of concentration of Cr in NIST-SRM 1646 Estuarine Sediment for
every batch of NAA irradiation for Cr in sediment (recovery %).
Batch (Date)
1 (27/9/2001)
2 (24/10/2001)
3 (24/10/2001)
4 (6/2/2002)
5 (6/2/2002)
6 (7/2/2002)
7 (7/2/2002)
8 (14/3/2002)
Average
Analyte (Cr in ppm)
80.26±0.78
56.37±1.98
51.136±2.43
76.34±1.32
49.07±0.76
52.03±1.56
82.79±0.93
67.56±1.33
64.44 ±13.99
Recovery %
105.6
74.2
67.3
100.4
65.0
68.5
109.0
89.0
85
4.4 Concentration of Heavy Metals
Trace amounts of some heavy metals such as manganese, iron, copper and zinc are
essential to aquatic life, but excess levels of these elements in water can be detrimental
(Law, 1981; Forstner-Wittman, 1981). Non-essential heavy metals of particular concern to
surface water systems are Cd, Cr, Hg, Pb, As and Sb (Jackson and Jackson, 1996). All
metals, including the essential metal micronutrients are toxic to aquatic organisms as well
as to humans if exposure levels are sufficiently high (Lewis, 1981).
This work is supported by the determination of As, Cu, Cd, Cr, Pb, Zn, Ni, Hg,
which are commonly studied because they are classified as principal pollutants and toxic
for human beings. Concentrations of heavy metals in water, plants and sediment from
112
sixteen sampling sites along the Sg. Skudai river system were obtained. Genuinely, this
study is hoped to help the responsible authorities to establish baseline data for future
reference. Moreover, the determination of heavy metals concentrations is imperative in
checking their toxicity in relation to surface water and the aquatic habitats.
The elemental concentrations below the IDL have not been reported in this work.
Aqueous samples concentrations were multiplied by the appropriate dilution factor. The
results was then rounded to two decimal places and reported as µg/L for the water samples
and µg/g for the solid samples. The quality control data obtained during the analyses
indicates the quality of the sample data and has been submitted with the sample results as
in the above section. Results obtained from the laboratory testing of the methods for
individual sampling were presented in tables for water, plants and for sediment (Appendix
5). The graphs for each sampling are depicted in figures for water, plants and sediment and
presented in Appendix 6.The average elemental concentrations for water were shown in
Figure 4.3 and Table 4.7. While, the summary of results for analysis of plant and sediment
from the river were presented in Table 4.8 (plant) and Table 4.9 (sediment). The graphical
forms of these results were presented in Figure 4.4 (i) and Figure 4.4 (ii) (plants) and
Figure 4.5 (sediment). The results of the heavy metals concentration were then compared
with the DOE Interim National Water Quality Standards for Malaysia and DOE Water
Quality Criteria and Standards for Malaysia as in appendix 2 and appendix 7 respectively
to determine the river condition and status.
A great deal of research has been directed towards the determination of heavy
metals in water, plant and sediment as to identify unusual occurrences of heavy metals
within the environment in association with industrial developments. In Table.4.10, Table
4.11 and Table 4.12 we have summarized some of the main areas with which this literature
is associated. These tables should not be considered as exhaustive or complete; it simply
identifies those industrial development and those metals for which extended occurrences
has been studied. Results from previous findings listed in these tables were then used as a
comparison in this study.
nd
nd
nd
nd
nd
3.42±0.06
nd
60.81±0.91
27.73±0.32
10.86±0.33
7.19±0.12
3.87±0.07
nd
4.30±0.03
nd
nd
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
62.50±0.44
40.71±1.05
38.33±0.18
125.18±1.76
44.07±0.53
26.99±0.30
21.06±0.36
29.18±0.09
40.40±0.27
41.10±0.20
34.71±0.33
25.69±0.08
77.86±0.27
64.66±0.71
31.93±0.38
82.09±0.44
Zn
*nd- not detected-below idl
Cr
Point
Sampling
13.43±0.24
9.32±0.07
9.43±0.05
12.20±0.32
13.23±0.24
1.62± 0.20
1.47±0.05
4.01±0.18
3.40±0.07
3.67±0.13
115.87±0.91
3.20±0.34
212.44±2.30
148.67±1.74
78.81±1.06
17.81±0.36
Ni
11.43±0.26
40.43±0.69
41.69±0.27
97.8±0.95
34.08±0.59
2.99±0.04
3.24±0.05
5.21±0.03
3.26±0.05
3.23±0.06
3.62±0.15
3.17±0.03
7.19±0.08
9.16±0.18
4.55±0.06
168.57±2.08
Cu
3.50±0.06
42.8±0.24
36.47±0.25
4.45±0.18
27.49±0.36
3.55±0.15
2.58±0.03
3.53±0.02
3.50±0.02
3.52±0.03
3.41±0.04
2.25±0.01
3.96±0.03
5.18±0.04
3.27±0.04
5.06±0.01
As
Pb
3.95±0.04
1.07±0.01
0.93±0.02
1.36±0.12
2.78±0.16
4.97±0.05
3.19±0.09
4.59±0.10
3.43±0.07
2.90±0.03
2.60±0.01
1.51±0.03
4.52±0.04
4.30±0.03
3.16±0.09
16.69±0.17
Element Concentration (µg/L)
2.63±0.12
0.12±0.02
0.07±0.02
0.29±0.04
0.07±0.03
0.16±0.06
0.19±0.04
0.14±0.04
0.15±0.08
0.13±0.03
0.11±0.02
0.14±0.02
0.47±0.00
0.54±0.02
0.13±0.02
0.54±0.02
Cd
nd
1.02±0.09
3.52±0.65
nd
0.44±0.00
0.97±0.02
0.32±0.01
0.97±0.06
0.45±0.00
0.75±0.04
0.49±0.01
0.30±0.00
nd
0.47±0.03
0.66±0.01
nd
Hg
Table 4.7 : Results of average elemental concentrations in the Sg. Skudai river water for 6 samplings and at 16 sampling locations
113
Concentration (µg/L)
0
50
100
150
200
250
1
2
Figure 4.3
3
4
Cr
Zn
6
Ni
7
Cu
As
Pb
8
9
Sampling points
Cd
10
Hg
11
12
13
Average elemental concentrations for water of theSg. Skudai river system
5
14
15
16
113
Cr
28.16±0.12
52.98±1.06
31.81±9.13
28.75±1.03
27.02±1.45
27.24±1.3
19.03±2.18
19.35±5.36
17.80±1.36
19.30±1.89
15.30±2.18
16.59±4.18
ab
40.69±0.64
ab
ab
Element Concentration (mg/g)
Zn
Ni
Cu
As
10489.44±1.99
nf
15.11±0.12
28.16±1.12
1353.05±2.19 2.08±2.13
10.96±2.15
0.98±0.42
3193.95±1.11 9.15±3.14
15.40±6.58
0.11±0.85
807.27±0.17
2.18±0.66
26.00±0.36
0.30±2.13
18598.16±3.19 3.81±0.45
14.94±2.45
nd,nf
1075.71±0.58 12.01±1.33 12.24±2.54
1.04±0.39
5451.84±1.25 2.99±6.61
12.48±0.48
nd,nf
2517.40±1.12 3.46±1.38
14.08±1.12
0.26±0.71
1513.66±1.51 2.09±0.14 11.71±02.35
0.49±0.25
1323.35±0.15 2.56±2.10
10.07±1.69
0.18±1.12
351.53±2.14
3.36±2.65
22.60±2.19
nf
1156.90±3.16 7.15±1.13
28.31±2.39
8.29±0.23
ab
ab
ab
ab
1378.70±1.02 9.84±2.87
18.08±2.15
nf
ab
ab
ab
ab
ab
ab
ab
ab
*ab-absence of plant at sampling location
*nd-not detected-below idl
*nf-not found (element not found in plant)
Sampling
Point
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Pb
10.03±0.29
4.67±3.12
3.72±1.16
6.22±0.23
5.94±0.24
10.14±5.12
4.00±3.16
2.71±5.60
3.82±1.15
2.52±1.78
1.48±4.16
2.33±0.39
ab
2.60±2.35
ab
ab
Cd
0.08±0.13
0.36±0.21
0.34±3.12
0.58±5.12
0.07±0.95
0.39±0.54
0.34±2.33
0.07±3.52
0.06±1.11
0.06±0.31
0.33±3.60
0.38±8.12
ab
0.37±2.99
ab
ab
Hg
nd
0.34±0.74
0.27±3.54
nd
nd
nd
nd
nd
nd
nd
nd
0.36±0.56
ab
0.33±0.22
ab
ab
Table 4.8 : Results of average elemental concentrations in the plants (Phragmites karka) from the Sg. Skudai River system for 6
samplings and at 16 sampling locations.
113
Concentration (mg/g)
0
10
20
30
40
50
60
70
80
2
Figure 4.4(i)
1
3
5
6
Ni
As
Cd
Hg
8
9
10
Sampling points
Cu
7
Cr
Pb
11
12
13
14
15
Average elemental concentrations for plants (Phragmites karka) from the Sg. Skudai river system
4
16
113
20000
19000
18000
17000
16000
15000
14000
13000
12000
11000
10000
9000
8000
7000
6000
5000
4000
3000
2000
1000
0
2
3
4
5
6
7
9
Zn
Sampling points
8
10
11
12
13
14
Figure 4.4(ii) Average zinc concentrations for plants (Phragmites karka) from the Sg. Skudai River system
1
15
16
113
Concentration (mg/g)
Cr
98.77±4.17
119.12±10.81
94.82±12.5
98.92±2.92
105.86±4.88
92.20±1.45
182.64±17.50
189.30±5.22
146.26±10.13
108.98±1.88
295.54±13.85
125.02±9.84
76.72±1.19
173.55±14.60
68.31±0.63
113.15±2.04
Zn
29.53±1.28
24.35±1.06
52.19±1.08
289.14±1.90
25.81±1.16
52.21±1.60
145.37±1.64
29.84±0.71
29.14±1.13
128.05±1.18
268.06±4.20
674.60±1.84
374.06±3.44
1246.94±7.19
42.90±2.41
84.73±1.84
*nd-not detected-below idl
*nf-not found (element not found in sediment)
Sampling
Point
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Element Concentration (mg/g)
Ni
Cu
As
15.87±1.85
9.36±0.31
7.34±0.32
14.80±1.05
3.87±0.16
5.23±0.26
8.88±1.46
9.12±0.20
7.25±0.20
7.69±1.14
10.29±0.14
9.04±0.10
5.36±2.85
5.09±0.15
4.02±0.07
17.40±0.70 16.26±1.18
8.22±0.23
7.73±2.58
12.42±0.59
7.60±0.24
9.84±0.55
14.81±0.28 16.95±0.51
14.97±0.89
8.30±0.34
18.01±0.42
9.80±0.39
16.65±0.43 11.41±0.18
4.20±1.46
16.44±0.49
3.44±0.10
5.15±1.91
33.00±1.27
5.24±0.11
9.97±2.17
30.22±0.80 11.83±0.48
13.82±1.83 228.21±1.29 8.30±0.50
6.46±0.14
15.12±0.20 12.89±0.14
14.20±0.29 12.23±0.38
13.96±0.5
Pb
38.41±1.70
12.99±0.85
12.66±0.23
18.72±0.20
7.13±0.15
13.33±0.26
8.61±0.21
6.46±0.16
6.30±0.14
140.75±0.27
2.80±0.09
8.96±0.12
12.78±0.31
22.12±1.72
12.60±0.18
16.27±0.38
Hg
nd
0.17±5.14
0.09±4.28
nd
0.01±2.14
nd
0.24±1.14
0.19±8.41
0.54±0.01
0.31±0.02
nd
2.01±0.01
0.74±0.13
4.73±0.04
nf
1.55±0.11
Table 4.9 : Results of average elemental concentrations for sediments from the Sg. Skudai river system for 6 samplings
and at 16 sampling locations
113
Concentration (µg/g)
0
200
400
600
800
1000
1200
1400
1
3
Figure 4.5
2
5
Zn
6
Ni
7
Cu
As
Pb
Hg
8
9
10
Sampling points
Cr
11
12
13
14
Average elemental concentrations for sediments from the Sg. Skudai River system
4
15
16
113
121
4.4.1
Arsenic
In this work, concentrations of arsenic in water, plant and sediment of the Sg.
Skudai river system were determined for samples taken from sixteen sampling sites and the
average values are reported in Table 4.13. Meanwhile, the graphical forms of the results
are shown in Figure 4.6. The average levels of As in water samples obtained from the Sg.
Skudai river system ranged from 2.25 µg/L to 42.8 µg/L for the sixteen sampling points.
The highest level of arsenic was obtained at sampling point 15 (Pulai) and the lowest at
sampling point 7 (Tmn. Teratai) as depicted in Figure 4.6. Meanwhile, the average arsenic
concentration found in this study in the waters of the Sg. Skudai river system is 9.66 µg/L.
Another study of other Malaysian river, Sg. Chuau (Putrajaya Wetlands catchment)
revealed arsenic concentrations in water ranging from 2.36 µg/L to 10.44 µg/L (Lee et al.,
2004). While, in the Sg. Langat, levels of arsenic recorded were 0.75 to 4.75 µg/L
(Muhammad Abu Yusuf et al., 1999). These levels are considered to be low, when
compared with arsenic concentration in Sg. Skudai river system. Besides that, previous
study of Sg. Skudai reported 1.00 µg/L of arsenic found in the river water (DOE, 2000).
Meanwhile, another study by DOE (1993), reported that the highest concentration of
arsenic in the river monitoring programme for that year was observed at the Sg. Skudai
with a concentration of 1.97 µg/L.
Studies in several countries reported levels of arsenic in water were ranged from
0.2 µg/L to 2536 µg/L (Inhat et al., 1993; Veado et al., 1997; Tariq et al., 1996) as shown
in Table 4.10.The recommended INWQS threshold level of arsenic for Malaysian rivers is
50 µg/L (Appendix 2). The average value of arsenic for all the sampling points of the river
system were within the INWQS threshold level for all classes. The level of arsenic in the
waters of Sg. Skudai river system is considered safe for human health. The natural and
anthropogenic source of arsenic in river waters and their toxic effects were already
discussed in Section 1.3.1.1 of Chapter I. Arsenic compounds are extensively used in the
wood processing industries to protect the timbers. Several wood processing industries are
functioning in the vicinity of the Sg. Skudai river system. These industries may use arsenic
compounds to protect timbers, though uses of these chemicals are officially banned.
Previous studies reported that arsenic levels in some rivers, such as Sg. Klang river, Sg.
Linggi river, etc. particularly at the downstream stretches, are apparently higher than the
natural level expected in uncontaminated waters. Evidence presented in some studies
(Cullen and Dodd, 1989) indicated that the probable sources of arsenic are leaching from
soils where sodium arsenite had been extensively used previously, effluents discharged
Previous
studies
Christensen
et.al, 1994
Reilly,
1991
Abaychi,
1985
Polprasert,
1982
Stoepler,
1992
Inhat et.al,
1993
No
1
2
3
4
5
6
Denmark
River
Say
England
River
Irwell
Iraq
Shatt AlArab
River
Thailand
Chao
Phraya
River
Germany
Rhine
River
Canada
Eastern
Ontario
Location
(River)
0.2-3(µg/L)
68.7(µg/L)
0.90 (µg/L)
1015000(µg/L)
Cu
0.050.2µg/L)
121.1(µg/L)
0.25(µg/L)
Cd
0.1-6(µg/L)
1 (µg/L)
123.3(µg/L)
10000-15
000(µg/L)
Cr
0.98.2(µg/L)
Hg
1-10 (µg/L)
0.06120(µg/L)
0.0227(µg/L)
242.6(µg/L)
1.8(µg/L)
5(µg/L)
0.0050.05µmol/L
Pb
160(µg/L)
3.4(µg/L)
Ni
Concentration of elements
Zn
0.2100(µg/L)
11.2177.8(µg/
L)
1015(mg/l)
Table 4.10: Results of previous studies from journals for elemental concentrations in water
0.2230(µg/L)
As
Sakino et.al,
1980
Sakai, et.al
Veadoet al,
1997
Tariq et.al,
1996
7
8
9
10
Table 4.10 Contd/-
Japan
Murasak
i River
Japan
Toyohir
a River
Brazil
Das
Velhas
River
India
Indus
River
0.3(µg/L)
2-22 (µg/L)
10-91
(µg/L)
1.011.7(µg/L)
41(µg/L)
5-39(µg/L)
7.213.5(µg/L)
10-41
(µg/L)
15(µg/L)
6-15(µg/L)
0.017-64.2
(mg/L)
0.065-0.245
(mg/L)
47.5(µg/L)
10-160
(µg/L)
45(µg/L)
16-56(µg/L)
0.010-0.174
(mg/L)
80(µg/L)
10-96(µg/L)
0.6202.536
(mg/L)
2.3(µg/L)
Previous
studies
Hans, et.al
1994
Reilly, 1991
Cowgill, 1974
Sandberg and
Allen, 1975
Stoepler,1992
Rajurkar and
Damame,1998
No
1
2
3
4
5
6
Germany
Holcus
lanatus
India
Medicine
plants
USA
Pine
USA
Merceya
ligulata
England
Becium
homlei
USA
Lettuce
Location
(Plant)
Cu
0.5286.497(mg/g)
0.69916.213
(µg/g)
Hg
0.19.5(mg/kg)
Cr
d1(µg/g)
Cd
1588.3150(mg/g)
2.4-4.5ppm
0.5-3.5
(mg/kg)
Ni
Concentration of elements
6059890(µg/g)
0.1-1000
(mg/kg)
Pb
Zn
1.14215.957(m
g/g)
Table 4.11 : Results of previous studies from journals for elemental concentrations in plants
1.23 (µg/g)
0.1-0.5
(µg/g)
As
Ilia
Rodushkin,1999
Miryakova,
1996
9
10
1(µg/g)
Russia
0.8Pondweed 23.5(µg/g)
Sweden
Wheat
0-1.4(µg/g)
1(µg/g)
0.359.9(µg/g)
1(µg/g)
0.56
(ppm)
Vietnam
Imperata
Cylindric
Tran van and
Teherani,1998
8
1.66
(µg/g)
3.3-8.0
(ppm)
Greece
Herbs
Kanias and
Philianos, 1978
7
Table 4.11 Contd/-
0.02(pp
m)
0.457.5(µg/g)
4(µg/g)
0.79(ppm)
2.79.5(ppm)
1.611.5(µg/g)
10(µg/g)
13.7332.2(µg/g)
1(µg/g)
7.58(ppm)
13-28(ppm)
5(µg/g)
0.23
(µg/g)
Previous
studies
Hans, et.al
1994
Schaller,et.al
(1994)
Reilly,1991
Abaychi 1985
No
1
2
3
4
London
River
Irwell
Iraq
Shatt AlArab
USA
Missisippi
River
Germany
Lake
sediment
Location
(Sediment
Type)
0.06(mg/k
g)
0.17-0.28
(µg/g)
21.844.0(µg/g)
Cd
2100(mg/kg)
Cu
81.8122.4(µg/g)
53000(mg/kg)
Cr
0.3(mg/kg)
Hg
10(mg/kg)
11.328.1(µg/g)
530811(µg/g)
Pb
10-800
(mg/kg)
5500(µg/g)
Ni
Concentration of elements
Zn
17.634.7(µg/g)
10300(mg/kg)
Table 4.12 :Results of previous studies from journals for elemental concentrations in sediment
0.006(µg/g)
0.0050.007(µg/)
As
Polprasert,
1982
Stoepler,1992
Tran van and
Teherani,199
8
Houba et al,
1983
Lo and Fung,
1991,
Ndiokwere,
1984
Sakai,
et.al,1986
Tariq et.al,
1996
5
6
7
8
9
10
12
13
Table 4.12 Contd/-
Hong
Kong
Hebe
Haven
Nigeria
River
Niger
Japan
Toyohira
River
India
Indus
River
Thailand
Chao
Phraya
River
Germany
River
Rhine
Vietnam
Dalat
Lake
Belgium
Vesdre
River
2.633.2(µg/g)
22(µg/g)
11.9
(mg/kg)
107580(mg/kg)
3.34-37.50
(µg/g)
0.0991.621(µg/g)
0.20(µg/g)
0.130.153(µg/g)
0.117
(mg/kg)
16195(mg/kg)
3.223.5(µg/g)
32(µg/g)
22.9
(mg/kg)
78.08(ppm)
80200(µg/g)
30->800
(mg/kg)
0.05(ppm)
47.50(µg/g)
0.505.47(µg/g)
0.165.71(µg/g)
0.027-0.034
(µg/g)
0.01(ppm)
1-10(mg/kg)
0.081.86(µg/g)
14.8135.3
(µg/g)
106.8110.5(µg/g)
7.568.13
(µg/g)
0.1161.205(µg/g)
24(µg/g)
28.6
(mg/kg)
2811833(mg/kg)
10-10000
(mg/kg)
8.94
(mg/kg)
3.68(pp
m)
d100
(mg/l)
50.00-195.00
(µg/g)
4.925.5(µg/g)
152(µg/g)
111.7114.2(µg/g)
1146
(mg/kg)
16294806(mg/kg)
0.081.86(µg/g)
0.167-1.520
(µg/g)
3.924.34(µg/g)
4.01(µg/g)
128
from industries manufacturing various forms of arsenicals, and continuing use of other
arsenical herbicides and pesticides.
Arsenic concentrations in plants were also determined for the sixteen sampling
locations and were showed in Table 4.13. Figure 4.8 shows the arsenic concentration
determined in plants from the Sg. Skudai river system. Consequently, the As concentration
in plants for the 16 sampling points ranged from 0.11 µg/g at sampling point 3 (Tmn.
Mewah) to 28.16 µg/g at sampling point 1 (Kg. Melayu Sedenak). The average level of As
found in the plants of the Sg. Skudai river system for the sixteen sampling points is 4.42
µg/g. The maximum recommended DOE Water Quality Criteria for Malaysia level of
arsenic to protect freshwater and estuarine aquatic life is 11.25 µg/g (Appendix 7). This
shows that the arsenic levels in plants from all sampling points for aquatic life are lower
than the recommended level except for sampling point 1 (Kg. Melayu Sedenak). This
could be due to the extensive usage of agricultural chemicals in the palm oil estate at the
sampling point mentioned above.
Concentrations of As in plants grown on uncontaminated soils vary from 0.009
µg/g to 1.5 µg/g with good correlations between the content of soils and plants. (Hans et
al., 1994). Previous studies from several countries as in Table 4.74 showed that As
concentration in plants were ranged from 0.1µg/g to 5.0 µg/g (Han et al., 1994; Sandberg
and Allen, 1975; Tran Van and Teherani, 1989; Rodushkin et al., 1999).
129
Table 4.13: Average arsenic concentrations for water, plant and sediment from the Sg.
Skudai river system
Sampling
Point
Water
(µg/L)
Plant
(µg/g)
Sediment
(µg/g)
1
3.55±0.15
28.16±1.12
7.34±0.32
2
2.58±0.03
0.98±0.42
5.23±0.26
3
3.53±0.02
0.11±0.85
7.25±0.20
4
3.50±0.02
0.30±2.13
9.04±0.10
5
3.52±0.03
nf
4.02±0.07
6
3.41±0.04
1.04±0.39
8.22±0.23
7
2.25±0.01
nf
7.60±0.24
8
3.96±0.03
0.26±0.71
16.95±0.51
9
5.18±0.04
0.49±0.25
18.01±0.42
10
3.27±0.04
0.18±1.12
11.41±0.18
11
5.06±0.01
nf
3.44±0.10
12
4.45±0.18
8.29±0.23
5.24±0.11
13
27.49±0.36
ab
11.83±0.48
14
3.50±0.06
nf
8.30±0.50
15
42.8±0.24
ab
12.89±0.14
16
36.47±0.25
ab
13.96±0.5
Average
9.66±13.19
4.42±9.27
*ab-absence of plant at sampling location
*nd-not detected-below idl
*nf-not found (element not found in plant, negative values)
9.42±4.38
130
45
40
Concentration
35
30
25
20
15
10
5
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16
Sampling Point
Water (µg/L)
Plant (µg/g)
Sediment (µg/g)
Figure 4.6 Average concentrations of arsenic in water, plant and sediment of the
sampling points.
Plants take up As passively with the water flow and increased As content was found in
plants near As emitting factories (Hans, 1994). This shows that the plants taken from the
Sg. Skudai river system are contaminated with As from the vicinity of factories along the
river system. Uptake of the element from soil by plants has been found to depend not only
on the soil concentration but also on the plant species. Some plants are, in fact, capable of
accumulating As in their tissues, (Reilly, 1991). The arsenic content of grass and crops in
general increases with soil content, but may be small compared with the large amounts in
some contaminated soils.
The As concentration in sediments taken from the river were also listed in Table
4.13 and depicted in Figure 4.6 for the sixteen sampling locations. Apparently, the
concentration of As in the sediment taken from the 16 sampling points were ranged from
3.44 µg/g to 18.01 µg/g. The highest average concentration was obtained from sampling
point 9 (Gelang Patah) and the lowest concentration was obtained from sampling point 11
(Tampoi). However, the average value of As obtained from the sediment of the Skudai
river system is 9.42 µg/g.
131
Previous studies as presented in Table 4.11 indicated that As concentration in
contaminated sediment ranged from 0.005 µg/g to 4.34 µg/g (Hans et al., 1994; Tran Van
and Teherani, 1989; Ndiokwere, 1984 ; and Tariq et al., 1984). Soils usually contains As
between 0.001 µg/g and 0.040 µg/g in the absence of industrial or agricultural
contamination (Reilly, 1991). This clearly shows that the As concentration obtained from
the sediments of the Sg. Skudai river system is highly polluted. Sediments normally
contain considerably higher amounts of As, compared to water and plants. Sediments are
always higher in arsenic than the waters with which they are associated (Fowler, 1983).
In terms of arsenic, the river waters of Sg. Skudai river system were suitable for the
support of aquatic life and supply water for domestic, industrial and agricultural uses
according to the standards.
4.4.2
Cadmium
In this study, concentrations of cadmium in water and plant of the Sg. Skudai river
system were determined for six samplings and the average values are reported in Table
4.14 and the graphical forms of the result are shown in Figure 4.7. Apart from that, the
average levels of Cd in water samples obtained from the Sg. Skudai river system ranged
from 0.1 µg/L to 2.63 µg/L for the sixteen sampling points as placed in Table 4.14. The
highest level of cadmium in water was obtained at sampling point 14 (Kg. Tlk. Serdang)
and the lowest at sampling point 13 and 16 (Kg. Pg. Rinting, Kg. Sg. Danga) as depicted in
Figure 4.9. The average cadmium concentration found in this study in the waters of Sg.
Skudai river system is 0.37 µg/L. A study of cadmium levels in Sg. Semenyih showed an
average concentration of 0.18 µg/L ( Lee et al., 2000). Besides that, another study by the
DOE (1996), reported cadmium concentrations of 0.0004 mg/L in Sg. Prai, 0.002 mg/L in
Sg. Kelang and 0.002 mg/L in Sg. Melaka.
Elsewhere it was reported that levels of cadmium in water ranging from 0.05 µg/L
to 121.1 µg/L as placed in Table 4.14 (Abayachi, 1985; Polprasert, 1982; Stoepler, 1992;
Sakino et al., 1980; Veado et al., 1997; Tariq et al., 1996). The recommended INWQS
threshold level of cadmium for Malaysian rivers is 10 µg/L. The average values of
cadmium for all the sampling points of the river system were within the INWQS threshold
level for all classes (Appendix 2). Cd concentrations in non-polluted natural waters usually
132
are lower than 1 µg/L, have been reported (Hans 1994). This shows that the Cd
concentration found in this study is below the polluted level and is safe for human
consumption after treatment. Cadmium compounds enter the water bodies from the
discharge of effluents from paint manufacturing industries where cadmium is used to
produce excellent colour from rechargeable battery (Wittmann, 1981). Other major sources
of Cd in river water come from sewerage treatment plants, pig farms and manufacturing
industries (IWK, 2000; Mazlin et al., 2000; Erdawati, 1997). Previous study of the Sg.
Skudai showed cadmium concentrations of 0.001 mg/L (DOE, 2000). In another study, the
level of cadmium concentration was found to be 26.0 µg/L in the river tributaries from the
catchments of Putrajaya Wetlands. This shows that cadmium levels are higher in other
rivers compared to the Sg. Skudai (Lee et al., 2004) Thus, cadmium levels in the Sg.
Skudai river water are below the polluted level and are suitable for human consumption.
133
Table 4.14: Average cadmium concentrations for water, plant and sediment from the Sg.
Skudai river system
Sampling
Point
Water
(µg/L)
Plant
(µg/g)
1
0.16±0.06
0.08±0.13
2
0.19±0.04
0.36±0.21
3
0.14±0.04
0.34±3.12
4
0.15±0.08
0.58±5.12
5
0.13±0.03
0.07±0.95
6
0.11±0.02
0.39±0.54
7
0.14±0.02
0.34±2.33
8
0.47±0.00
0.07±3.52
9
0.54±0.02
0.06±1.11
10
0.13±0.02
0.06±0.31
11
0.54±0.02
0.33±3.60
12
0.29±0.04
0.38±8.12
13
0.07±0.03
ab
14
2.63±0.12
0.37±2.99
15
0.12±0.02
ab
16
0.07±0.02
ab
Average
0.37±0.62
0.26±0.17
*ab-absence of plant at sampling location
134
3
Concentration
2.5
2
1.5
1
0.5
0
1
2
3
4
5
6
7 8 9 10 11 12 13 14 15 16
Sampling Points
Water (µg/L)
Figure 4.7
points
Plant (µg/g)
Average concentrations of cadmium in water, and plant of the sampling
Cadmium concentrations in plants were determined for the sixteen sampling locations
and also showed in Table 4.14 and depicted in Figure 4.7. Analysis of the plants indicated
that the Cd concentration in plants for the sixteen sampling points ranged from 0.06 µg/g at
sampling point 9 and 10 (Gelang Patah, K. Selatan) to 0.58 µg/g at sampling point 4 (Kg.
Pertanian). The calculated average concentration of Cd in plants from the Sg. Skudai river
system is 0.26 µg/g. When compared with the Cd level in the threshold value, it was found
that Cd concentration exceeded the recommended DOE Water Quality Criteria for
Malaysia level for aquatic life (0.175 µg/g) (Appendix 7). Besides that, concentrations of
Cd in plant samples from all the sampling points were higher than the recommended level
except for sampling points 1 (Kg. Melayu Sedenak), 5 ( Saleng), 8 (Tmn. Universiti), 9
(Gelang Patah) and 10 (Kolej Selatan). An increased level of Cd in the plant samples from
the Sg. Skudai river system is most observed at the downstream of the river. This is most
probably caused by the battery industries operating at the downstream of the river system.
Meanwhile, a study of heavy metals in mangrove trees in Sg. Sepang Kecil found that the
concentration of cadmium in this plant is 2.59 µg/g (Baktini Sawawi, 1999). Therefore, the
concentration of cadmium in Phragmites karka from the Sg. Skudai is definitely lower
than the former.
135
Concentrations of Cd in uncontaminated plants are 0.1 µg/g (Bowen, 1966). Previous
studies from several countries indicated that the Cd concentrations in plants were ranging
from 0.1µg/g to 16.21µg/g as presented in Table 4.11 (Miryakova, 1996; Rajurkar and
Damame, 1998; Stoepler, 1992; Tran Van and Teherani, 1998;and Rodushkin et al., 1999).
This shows that the concentration of Cd in plants taken from the Sg. Skudai river system is
slightly contaminated when compared with the concentration of Cd in uncontaminated
plants. Rice, in polluted areas of Japan, where itai-itai disease occurred, had approximately
1µg/g of the metal, compared to levels of 0.05-0.07 µg/g in non-polluted regions.
In terms of cadmium, the river water of Sg. Skudai river system is suitable for the
supply of water for domestic, industrial and agricultural uses, but unsuitable for support of
aquatic life. The health of the aquatic ecosystem of Sg. Skudai river system is slightly
under stress and the river system is unable to provide good ecosystem services.
4.4.3
Chromium
In this study, concentrations of chromium in the Sg. Skudai river water were
determined and the average values are reported in Table 4.15. Meanwhile, the graphical
forms of the result are depicted in Figure 4.8. The average chromium concentrations
determined in the water samples taken from the Sg. Skudai river system is 16.88 µg/L.
Apart from that, the average levels of Cr in water samples obtained from the Sg. Skudai
river system ranged from 3.42 µg/L to 60.81 µg/L for the 16 sampling points as shown in
Figure 4.8. The highest level of chromium was obtained at sampling point 8 (Tmn.
Universiti) and the lowest level of chromium was obtained at sampling point 6 (Kg. Jaya
Sepakat) as depicted in Figure 4.8. The DOE (2000) reported 0.002 mg/L of chromium
found in the Sg. Skudai in year 2000 and 0.0011 mg/L in year 1999. Meanwhile, Lee et al.
(2004), found that the concentration of chromium in the Sg. Chuau ranged from 4.33 to
23.20 µg/L. The concentration of chromium in several other rivers in Malaysia were Sg.
Prai (0.061 mg/L), Sg. Kelang (0.091 mg/L) and in Sg. Melaka (0.022 mg/L) (DOE, 1996).
Apart from that, the concentration of chromium in Sg. Semenyih, Selangor was 0.59 µg/L
and this is very low compared to concentration of chromium in Sg. Skudai (Lee et al.,
2000).
136
Several countries reported levels of chromium in water ranging from 0.1 µg/L to 15
000 µg/L based on Table 4.10 (Reilly, 1991; Polprasert, 1982; Stoepler, 1992; Sakai et al.,
1986; Inhat et al., 1993; Veado et al., 1997; Tariq et al., 1996). Besides that, Edwards
(1993) also reported that chromium in water ranged from 0.01 to 4.00µg/L in the US
(Appendix 2). The recommended INWQS threshold level of chromium for Malaysian
rivers is 50 µg/L. The average values of chromium for all the sampling points of the river
system were within the INWQS threshold level for all classes except for Taman. Universiti
(sampling point 8). Therefore, the water of Sg. Skudai river system is safe for domestic
water supply except for at Taman Universiti where there are many electroplating industries
present. Though water may contain some chromium, especially if it is affected by emission
from industry, it is unlikely to make a significant contribution to chromium intake. The
presence of Cr (III) in drinking water is unlikely because of the low solubility of the
hydrated Cr (III) oxide. The more soluble Cr (VI) may occur in water especially in the
vicinity of industries, which cause pollution (Law and Singh, 1986).
137
Table 4.15 : Average chromium concentrations for water, plant and sediment from the Sg .
Skudai river system
Sampling
Point
Water
(µg/L)
Plants
(µg/g)
Sediment
(µg/g)
1
nd
28.16±2.33
98.77±4.17
2
nd
52.97±1.14
119.12±10.81
3
nd
31.81±5.01
94.82±12.5
4
nd
59.57±3.11
98.92±2.92
5
nd
38.06±1.22
105.86±4.88
6
3.42±0.06
27.24±4.30
92.20±1.45
7
nd
19.03±1.16
182.64±17.50
8
60.81±0.91
68.63±2.85
189.30±5.22
9
27.73±0.32
46.37±3.14
146.26±10.13
10
10.86±0.33
41.29±2.75
108.98±1.88
11
7.19±0.12
38.63±4.16
295.54±13.85
12
3.87±0.07
27.87±4.31
125.02±9.84
13
nd
ab
76.72±1.19
14
4.30±0.03
40.69±1.19
173.55±14.60
15
nd
ab
68.31±0.63
16
nd
ab
113.15±2.04
Average
16.88±21.15
26.46±10.79
130.57±56.89
*ab-absence of plant at sampling location
*nd-not detected-below idl
138
Concentration
400
300
200
100
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16
Sampling Points
Water (µg/L)
Plant (µg/g)
Sediment (µg/g)
Figure 4.8 Average concentrations of chromium in water, plant and sediment of the
sampling points
Concentrations of chromium in plants range from 19.03 µg/g at sampling point 7
(Tmn. Teratai) to 68.63 µg/g at sampling point 8 (Taman. Universiti). These results can be
observed in Table 4.15 and Figure 4.8. On the other hand, the average concentration of
chromium in plants determined in the Sg. Skudai river system is 26.46 µg/g. This value is
above the DOE Water Quality Criteria for Malaysia threshold limit for aquatic life in
freshwater and estuarine (13.5 µg/g) (Appendix 7). It was found that the level of chromium
in uncontaminated plants is 2 ppm (Bowen, 1966; Allaway 1968). The concentration of
chromium is high is due to the presence of a high number of vehicle repair workshops
along the river system. Chromium could also be accumulated due to the excess usage of
paint and wear-resistant surface treatments used in the workshops. The chromium value at
all sampling locations also exceeded the recommended value for protection of aquatic life
by DOE Water Quality Criteria for Malaysia (Appendix 7). In the Sg. Sepang Kecil, the
concentration of chromium in mangrove trees was reported to be 0.76 µg/g (Baktini
Sawawi, 1999). This shows that a lower concentration of chromium is found in plants from
Sg. Sepang Kecil compared to the plants from the Sg. Skudai.
Besides that, sediment from the Sg. Skudai river showed the concentrations of
chromium of between 68.31µg/g at sampling point 15 (Pulai) to 295.54 µg/g at Tampoi.
These results were presented in Table 4.15 and Figure 4.8. The mean concentration of
sediment from the river is 135.57 µg/g. Elsewhere, it was reported that chromium level in
sediments from Thailand is 47.50 µg/g and in Iraq the level of chromium in sediment is
139
122.4 µg/g as placed in Table 4.15 (Polprasert, 1982; Abaychi and Douabul, 1985).
Whereas, in the coastal areas of the Johor state, it was found that chromium concentrations
ranged from 32.3 to 115 µg/g (Yusof et al., 1995). Therefore, the chromium concentration
at all sampling points in the Sg. Skudai river system is higher than the results of the
previous studies mentioned above. High levels of Cr show that the sediment is rather
polluted and this could be due to the high concentration of chromium in the effluents from
the active industrial zones along the river system, especially electroplating and printing
factories. In Sg. Sepang kecil, concentrations of chromium were found to be 10.65 µg/g
(Baktini Sawawi, 1999). Comparatively, the sediments from the Sg. Skudai river is highly
polluted with chromium.
Hence, chromium in the waters of the Sg. Skudai river system is noted to be
suitable for the supply of water for domestic, industrial and agricultural uses. But it is
considered polluted for the aquatic life in the river ecosystem. Even the aquatic life present
in the river would be in danger due to the higher level of chromium compared to the
recommended level for aquatic life by the DOE Water Quality Criteria for Malaysia
(Appendix 7).
4.4.4
Copper
The average concentrations of copper in water, plant and sediment samples of the
Sg. Skudai river system were determined and reported in Table 4.16. Meanwhile, the
graphical forms of the results are shown in Figure 4.9. Apart from that, the average levels
of Cu in water samples obtained from the Sg. Skudai river system ranged from 2.99 µg/L
to 168.57 µg/L for the 16 sampling points as shown in Table 4.16. The highest level of
copper was obtained at sampling point 11 (Tampoi) and the lowest at sampling point 1
(Kg. Melayu Sedenak) as depicted in Figure 4.9. The average copper concentration
determined in the waters of Sg. Skudai river system is 27.48 µg/L. Previous studies of the
Sg. Skudai river mouth reported 252. 8 µg/L of copper during low tide. Apart from that,
Lee et al. (2000) reported that the copper concentration in the Sg. Semenyih is of 0.74
µg/L. This results shows that the river has a lower concentration of copper compared to the
Sg. Skudai. Meanwhile, another study conducted in the Sg. Juru, shows that the copper
concentration reported was 2.0 µg/L. (Mat, I. and Maah, M. J. 1994a). This shows that the
water of the Sg. Skudai river is highly polluted with copper.
140
Table 4.16: Average copper concentrations for water, plant and sediment from the Skudai
River system
Sampling
Point
Water
(µg/L)
Plant
(µg/g)
Sediment
(µg/g)
1
2.99±0.04
15.11±0.12
9.36±0.31
2
3.24±0.05
10.96±2.15
3.87±0.16
3
5.21±0.03
15.40±6.58
9.12±0.20
4
3.26±0.05
26.00±0.36
10.29±0.14
5
3.23±0.06
14.94±2.45
5.09±0.15
6
3.62±0.15
12.24±2.54
16.26±1.18
7
3.17±0.03
12.48±0.48
12.42±0.59
8
7.19±0.08
14.08±1.12
14.81±0.28
9
9.16±0.18
11.71±02.35
8.30±0.34
10
4.55±0.06
10.07±1.69
16.65±0.43
11
168.57±2.08
22.60±2.19
16.44±0.49
12
97.8±0.95
28.31±2.39
33.00±1.27
13
34.08±0.59
ab
30.22±0.80
14
11.43±0.26
18.08±2.15
228.21±1.29
15
40.43±0.69
ab
15.12±0.20
16
41.69±0.27
ab
12.23±0.38
Average
27.47±45.32
16.31±5.84
27.59±54.07
*ab-absence of plant at sampling location
Studies in several countries reported levels of copper in water ranging from 0.2
µg/L to 15 000 µg/L as indicated in Table 4.10 (Reilly, 1991; Polprasert, 1982; Abaychi
and Douabul, 1985; Sakino et al., 1980; Sakai et al., 1986; Inhat et al., 1993; Veado et al.,
1997; Tariq et al., 1996). Elsewhere, (UKM-DOE, 2000) reported the copper concentration
in Sg. Kelang, Sg. Gombak and Sg. Selangor ranging from 0.27 µg/L to 57.30 µg/L. The
recommended INWQS threshold level of copper for Malaysian rivers is 20 µg/L
141
(Appendix 2). The average values of copper concentrations for all sampling points of the
river system were within the INWQS threshold level for all classes except for sampling
point 11 (Tampoi), 12 (Kg. Skudai Kiri), 13 (Kg. Pang. Rinting), 15 (Pulai) and sampling
point 16 (Kg. Sg. Danga). All these sampling points are located at the river estuary and the
river mouth, which is a crowded industrial zone and there are many electronic companies
there. This show the major sources of copper in the river water were contributed by the
industries located at the downstream of the river.
Copper concentrations in plants were also determined and are showed in Table
4.16. Meanwhile, Figure 4.9 depicts the copper concentrations in plants for the 16
sampling locations. However, the copper concentration in plants for the 16 sampling points
ranged from 10.07 µg/g at sampling point 10 (Kolej Selatan) to 28.31 µg/g at sampling
point 12 (Kg. Skudai Kiri ). The recommended DOE Water Quality Criteria for Malaysia
threshold level for copper in aquatic life is 2 µg/g (Appendix 7). This shows that the plants
from all the sampling points along the Sg. Skudai river have copper concentrations more
than the recommended level. The average level of Cu found in the plants of the Sg. Skudai
river system for the 16 sampling points is 16.31 µg/g. Hence, this too indicates that the
average level of copper in plants from the Sg. Skudai river system is higher than the
recommended level. Meanwhile, Hashim Baharin (1992), reported concentration of copper
in the leaves of Pterocarpus indicus plant in the Johor Bharu area ranging from 9.00 to
38.15 µg/g. Baktini Sawawi (1999) also reported that the copper concentration in
mangrove trees from Sg. Sepang Kecil were found to be 4.33 µg/g. This shows that the
copper concentration in the plants from Sg. Sepang Kecil is lower than Sg. Skudai.
142
250
Concentration
200
150
100
50
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16
Sampling points
Water (µg/L)
Plant (µg/g)
Sediment (µg/g)
Figure 4.9 Average concentrations of copper in water, plant and sediment of the
sampling points.
The concentration of Cu in plants grown on uncontaminated soils is 7 µg/g
(Bowen, 1966). Table 4.9 shows that Cu concentrations determined in plants from polluted
areas were ranged from 0.8 µg/g to 23.5 µg/g (Rodushkin et al., 1999; Miryakova, 1996).
From these results, we can deduce that the plants taken from the Sg. Skudai river system
are contaminated with Cu from the vicinity of electrical appliances factories around the
river system. Apparently, copper excess can also arise as a result of prolonged application
of copper-based fungicides in old orchards or in the timber industry which is also present
at the study area.
The Cu concentration in sediments taken from the river were also determined and
listed in Table 4.16 and shown in Figure 4. 9 for the six samplings. Apparently, the
concentrations of Cu in the sediment taken from the 16 sampling points ranged from 3.87
µg/g to 228.41 µg/g. The highest average concentration was obtained from sampling point
14 (Kg.Tlk.Serdang) and the lowest concentration was obtained from sampling point 2
(Sengkang). Meanwhile, the average value of Cu obtained from the sediment of the Sg.
Skudai river system is 27.59 µg/g. A study carried out at the Sg. Langat, Selangor reported
4.5 µg/g of copper in sediments from the river (M. Shuhaimi Othman and A. R.
Nurlailawati, 2004).
143
It was reported elsewhere, that the Cu concentration in sediments ranged from 2
µg/g to 580 µg/g as indicated in Table 4.16 (Say et al., 1981; Reilly, 1991; Abaychi and
Douabul, 1985; Polprasert, 1982; Houba et al., 1983; Lo and Fung, 1991; Sakai et
al.,1986; Tariq et al., 1984). Sediments usually contain 100 µg/g of copper in the absence
of industrial or agricultural contamination (Bowen, 1966). This clearly shows that the Cu
concentration in sediments obtained from sampling point 14 (Kg. Tlk. Serdang) is highly
polluted by electroplating industries functioning at the vicinity of the river system.
On the whole, based on the results for copper, the river waters of Skudai river
system were suitable for the support of aquatic life and supply water for domestic,
industrial and agricultural uses for the above mentioned sampling points. However, due to
the high copper concentrations in the plants samples from the river system, the health of
the aquatic ecosystem of Sg. Skudai river system is certainly under stress and thus, the
river system is unable to provide proper ecosystem services. The accumulations of Cu in
sediments were also observed especially at the river estuary.
4.4.5
Lead
The concentrations of lead in water, plant and sediment of the Skudai river system
were determined and the average values are reported in Table 4.17. Meanwhile, the
graphical forms of the result are depicted in Figure 4.10. The average levels of Pb in water
samples obtained from the Sg. Skudai river system ranged from 0.93 µg/L to 16.69 µg/L
for the 16 sampling points as shown in Table 4.17. The highest level of lead was obtained
at sampling point 11 (Tampoi) and the lowest at sampling point 16 (Kg. Sg. Danga).
Meanwhile, the average lead concentration found in this study in the waters of Sg. Skudai
river system is 3.87 µg/L. Previous study of the Sg. Skudai reported 0.010 mg/L of lead
(DOE, 2000). Meanwhile, another study by DOE (1999) reported 0.0002 mg/L of lead in
the Sg. Skudai.
Other rivers in Malaysian reported levels of lead ranging from 1.63 µg/L to 81.75
µg/L (UKM, 1996). Effluent discharges from sewage treatment plant, pig farms and
industries are the main contributors. The recommended INWQS threshold level of lead for
Malaysian rivers is 50 µg/L (Appendix 2). The results shows that the average value of lead
for all the sampling points of the river system were within the INWQS threshold level for
144
all the classes. Thus, in terms of lead the water is suitable for domestic water supply.
Elsewhere, it was reported that lead in water of Sg. Chuau, ranged from 1.14 to 7.20 µg/L
(Lee et al., 2004). While in Sg. Semenyih, the concentrations of lead was 24 to 1 mg/L
(Md. Rozali Othman et al., 1999).
The concentration of lead in plants were determined and showed in Table 4.17 and
Figure 4.10. The highest concentration was observed at sampling point 6 (Kg. Jaya
Sepakat) and the lowest at sampling point 11 (Tampoi). The average concentration of lead
in the plants from the Sg. Skudai river system for the six samplings is 4.63 µg/g. The
recommended DOE Water Quality Criteria for Malaysia threshold level for lead is 0.325
µg/g (Appendix 7). Hence, it is observed that the concentrations of lead from all the
sampling points in the river system exceeded the recommended level for aquatic life.
Plants from uncontaminated regions were reported to have 3.3 µg/g ( Bowen,
1966). Therefore, it can be deduced that the plants samples from all the sampling points
were contaminated with lead except for plant samples from sampling points 8 (Tmn.
Universiti), 10 (Kolej Selatan), 11 (Tampoi), 12 (Kg. Skudai Kiri) and 14 (Kg. Tlk.
Serdang). The contribution of copper in the river downstream could be due to activities
such as usage of high number of chemical, printing factories, while usage of fertilizer in
the estates upstream and piping activities along the river system were other sources of
pollution. Other study of heavy metals in plants showed 8.39 µg/g of lead in mangrove
trees (Baktini Sawawi, 1999). While, another study of heavy metals in plants (Pterocarpus
indicus) reported 5.25 µg/g to 49.33 µg/g of lead in the leaves of the plant (Hashim
Baharin, 1992).
The Pb concentration in sediments taken from the river were also determined and
listed in Table 4.17 and shown in Figure 4.10. The sediments taken from the river system
for the six samplings contained Pb ranged from 2.80 µg/g to 140.75 µg/g. The highest
average concentration was obtained from sampling point 10 (Kolej Selatan) and the lowest
concentration was obtained from sampling point 11 (Tampoi). Besides that, the average
value of Pb obtained from the sediment of the Sg. Skudai river system is 21.30 µg/g.
Meanwhile, other studies in Malaysia reported 30 µg/g of lead in sediment from Kuala
Selangor and 15 µg/g in sediment from Sg. Jejawi (Mat, I. and Maah, M. J., 1994b).
145
Pb concentration in contaminated sediment ranged from 0.12 µg/g to 10 000 µg/g
as reported by other previous studies in Table. 4.12 (Say et al., 1981; Reilly, 1991;
Abaychi and Douabul, 1985; Polprasert, 1982; Stoepler, 1992; Ndiokwere, 1984; Houba et
al., 1983; Lo and Fung, 1991; Sakai et al., 1986; Tariq et al., 1984). Sediments usually
contain 100 µg/g in the absence of industrial or agricultural contamination (Bowen, 1966).
Whereas, (Yusof et al., 1995) reported concentration of lead in coastal sediments of South
Johore, Malaysia is 42.8 µg/g. This clearly shows that the Pb concentration obtained from
the sediments of the Sg. Skudai river system is slightly polluted by industrial and domestic
activity.
146
Table 4.17 : Average lead concentrations for water, plant and sediment from the Sg.
Skudai river system
Sampling
Point
Water
(µg/L)
Plant
(µg/g)
Sediment
(µg/g)
1
4.97±0.05
10.03±0.29
38.41±1.70
2
3.19±0.09
4.67±3.12
12.99±0.85
3
4.59±0.10
3.72±1.16
12.66±0.23
4
3.43±0.07
6.22±0.23
18.72±0.20
5
2.90±0.03
5.94±0.24
7.13±0.15
6
2.60±0.01
10.14±5.12
13.33±0.26
7
1.51±0.03
4.00±3.16
8.61±0.21
8
4.52±0.04
2.71±5.60
6.46±0.16
9
4.30±0.03
3.82±1.15
6.30±0.14
10
3.16±0.
2.52±1.78
140.75±0.27
11
16.69±0.17
1.48±4.16
2.80±0.09
12
1.36±0.12
2.33±0.39
8.96±0.12
13
2.78±0.16
ab
12.78±0.31
14
3.95±0.04
2.60±2.35
22.12±1.72
15
1.07±0.01
ab
12.60±0.18
16
0.93±0.02
ab
16.27±0.38
Average
3.87±3.65
4.63±2.78
21.30±32.91
*ab-absence of plant at sampling location
Concentration
147
160
140
120
100
80
60
40
20
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16
Sampling Points
Water (µg/L)
Plant
Sediment (µg/g)
Figure 4.10 Average concentrations of lead in water, plant and sediment samples of the
sampling pointsd
The river waters of Sg. Skudai river system were suitable for the support of aquatic
life and supply water for domestic, industrial and agricultural uses for the above-mentioned
samplings and sampling points. However, due to the high copper concentration in the
plants and sediments from the river system, the health of the aquatic ecosystem of Sg.
Skudai river system is under stress and the river system is unable to provide ecosystem
services.
4.4.6
Mercury
In this work, concentrations of mercury in water, plant and sediment of the Sg.
Skudai river system were determined and the average values are reported in Table 4.18.
The average mercury concentration found in this study in the waters of Sg. Skudai river
system is 0.86 µg/L. Meanwhile, the graphical forms of the result are depicted in Figure
4.11. The average levels of Hg in water samples obtained from the Sg. Skudai river system
ranged from 0.30 µg/L to 3.52 µg/L for the 16 sampling points as shown in Table 4.18.The
highest level of mercury was obtained at sampling point 16 (Kg.Sg.Danga) and the lowest
at sampling point 7 (Tmn.Teratai) as depicted in Figure 4.11. Previous study in the Sg.
Skudai reported concentration of Hg 0.0002 mg/L (DOE, 2000). While Lee et al. (2000),
reported 0.018 µg/L in the Sg. Semenyih. Besides that, a concentration of 0.77µg/L to 0.97
µg/L of mercury was found in the Sg. Chuau (Lee et al., 2004).
148
Previous studies in several countries reported levels of mercury in water were
ranged from 0.017 µg/L to 64.2 µg/L (Polprasert, 1982; Tariq et al., 1996). Mercury
concentrations in the Sg. Langat river basin were reported to range from 0 to 4 µg/L
(Sarmani, 1985). The recommended INWQS threshold level of mercury for Malaysian
rivers is 1.00 µg/L (Appendix 2). The average values of mercury for all the samplings and
also all the sampling points of the river system were within the INWQS threshold level for
all classes except for sampling point 15 (Pulai) and Kg. Sg. Danga (16). These sampling
points are exactly at the river mouth and the accumulation of Hg from the industrial areas
along the river is observed here.
Mercury concentrations in plants were also determined for the 16 sampling points
and showed in Table 4.18. Meanwhile, Figure 4.11 shows the mercury concentration in
plant for the 16 sampling points. The highest concentration obtained was 0.27 µg/g at
sampling point 3 (Tmn. Mewah), and the lowest concentration was 0.36 µg/g at sampling
point twelve (Kg. Skudai Kiri). The average concentrations of Hg in plants from the 16
sampling locations are shown in Table 4.18 and depicted in Figure 4.11. The average level
of Hg found in the plants of the Skudai river system for the 16 sampling points is 0.32
µg/g. Previous studies from several countries showed that Hg concentration in plants from
polluted areas were ranged from 0.02 µg/g to 649.7 µg/g (Stoepler, 1992; Rajurkar and
Damame, 1998; Tran Van and Teherani, 1989a). The DOE Water Quality Criteria for
Malaysia recommends 0.025µg/g for protection of aquatic life (Appendix 7). Thus, the
levels of Hg in plant samples from the Sg. Skudai river system at all sampling points are
higher than the recommended value.
The Hg concentrations in sediments taken from the river were also determined and
listed in Table 4.18 and shown in Figure4.11. The sediments taken from the river system
for the six samplings contained Hg ranged from 0.31 µg/g to 4.73 µg/g. The highest
average concentration was obtained from sampling point 14 (Kg.Tlk.Serdang) and the
lowest concentration was obtained from sampling point 10 (Kolej Selatan). Meanwhile, the
average value of Hg obtained from the sediment of the Sg. Skudai river system is 1.65
µg/g.
Several previous studies indicated that Hg concentration in contaminated sediment
ranged from 0.01µg/g to 10 µg/g as placed in Table 4.18 (Reilly, 1991; Polprasert, 1982;
Stoepler, 1992; Ndiokwere, 1984; Tariq et al., 1984; Tran Van and Teherani, 1998).
149
Sediments usually contain 0.01 µg/g to 0.3 µg/g Hg in the absence of industrial or
agricultural contamination (Bowen, 1966). This clearly indicates that the overall Hg
concentration obtained from the sediments of the Sg. Skudai river system and
concentrations of Hg determined in plant samples from all the sampling points along the
river is polluted due to industrial activities along the river system.
Table 4.18: Average mercury concentrations for water, plant and sediment from the Sg.
Skudai river system
Sampling
Point
Water
(µg/L)
Plant
(µg/g)
Sediment
(µg/g)
1
0.97±0.02
nd
nf
2
0.32±0.01
0.34±0.74
nd
3
0.97±0.06
0.27±3.54
nd
4
0.45±0.00
nd
nf
5
0.75±0.04
nd
nd
6
0.49±0.01
nd
nf
7
0.30±0.00
nd
nd
8
nd
nd
nd
9
0.47±0.03
nd
0.54±0.01
10
0.66±0.01
nd
0.31±0.02
11
nd
nd
nf
12
nd
0.36±0.56
2.01±0.01
13
0.44±0.00
ab
0.74±0.13
14
nd
0.33±0.22
4.73±0.04
15
1.02±0.09
ab
nf
16
3.52±0.65
ab
1.55±0.11
Average
0.86±0.87
0.32±0.04
1.65±1.64
*ab-absence of plant at sampling location
*nd-not detected-below idl
*nf-not found (element not found in plant, negative values)
150
In terms of Hg, the river waters of Sg. Skudai river system were suitable for the
supply of water for domestic, industrial and agricultural uses for the above mentioned
sampling points. However, due to the high copper concentration in the plant and sediment
from the river system, it can be concluded that the health of the aquatic ecosystem of Sg.
Skudai river system is under stress and the river system is certainly unable to provide
ecosystem services.
5
4.5
Concentration
4
3.5
3
2.5
2
1.5
1
0.5
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16
Sampling Points
Water (µg/L)
Plant (µg/g)
Sediment (µg/g)
Figure 4.11
Average concentrations of mercury in water, plant and sediment of the
sampling points.
151
4.4.7
Nickel
In this study, concentrations of nickel in water, plant and sediment of the Sg.
Skudai river system were determined for six samplings and the average values are reported
in Table 4.19. Meanwhile, the graphical forms of the result are shown in Figure 4.14. Apart
from that, the average levels of Ni in water samples obtained from the Sg. Skudai river
system ranged from 1.47 µg/L to 212.44 µg/L for the 16 sampling points as shown in
Table 4.19. The highest level of nickel was obtained at sampling point 8 (Tmn. Universiti)
and the lowest at sampling point 2 (Sengkang) as depicted in Figure 4.12. Meanwhile, the
average nickel concentration found in this study in the waters of Sg. Skudai river system is
40.54 µg/L. A study by Lee (1999), reported concentration of nickel found in Sg. Juru was
1.6 to 1.8 µg/L. Comparatively the concentration of nickel in Sg. Skudai is very high.
Studies in several countries reported levels of nickel in water ranging from 0.02
µg/L to 60 µg/L (Stoepler, 1992; Tariq et al., 1996; Abaychi and Douabul, 1985; Inhat et
al., 1993; Veado et al., 1997). The recommended INWQS threshold level of Nickel for
Malaysian rivers is 900 µg/L (Appendix 2).The average values of all the samplings and
also all the sampling points of the river system were within the INWQS threshold level.
The natural and anthropogenic source of nickel in river waters and their toxic effects were
already discussed in Section 1.3.1.7 of Chapter I.
Nickel concentrations in plants were also determined for the six samplings and
showed in Table 4.19. Meanwhile, Figure 4.12 shows the nickel concentration in plant for
the six samplings. The nickel concentration in plants for the 16 sampling points ranged
from 2.08 µg/g at sampling point 2 (Sengkang) to 12.01 µg/g at sampling point 6 (Kg. Jaya
Sepakat ). The average level of Ni found in the plants of the Sg. Skudai river system for the
16 sampling points is 5.06 µg/g. The DOE Water Quality Criteria for Malaysia shows that
the recommended level of Ni for protection of aquatic life is 225 µg/g (Appendix 7).
Therefore, the concentration of Ni is below the recommended level for plant samples from
the river. Previous studies from several countries showed that Hg concentration in plants
from polluted areas were ranged from 0.4 µg/g to 158 µg/g (Reilly, 1991; Cowgill, 1974;
Kanias and Philianos, 1978; Rodushkin et al., 1999; Miryakova, 1996, Rajurkar and
Damame, 1998;Tran Van and Teherani, 1989a).
152
Table 4.19 : Average nickel concentrations for water, plant and sediment from the Sg.
Skudai river system
Sampling
Point
Water
(µg/L)
Plant
(µg/g)
Sediment
(µg/g)
1
1.62± 0.20
nf
15.87±1.85
2
1.47±0.05
2.08±2.13
14.80±1.05
3
4.01±0.18
9.15±3.14
8.88±1.46
4
3.40±0.07
2.18±0.66
7.69±1.14
5
3.67±0.13
3.81±0.45
5.36±2.85
6
115.87±0.91
12.01±1.33
17.40±0.70
7
3.20±0.34
2.99±6.61
7.73±2.58
8
212.44±2.30
3.46±1.38
9.84±0.55
9
148.67±1.74
2.09±0.14
14.97±0.89
10
78.81±1.06
2.56±2.10
9.80±0.39
11
17.81±0.36
3.36±2.65
4.20±1.46
12
12.20±0.32
7.15±1.13
5.15±1.91
13
13.23±0.24
ab
9.97±2.17
14
13.43±0.24
9.84±2.87
13.82±1.83
15
9.32±0.07
ab
6.46±0.14
16
9.43±0.05
ab
14.20±0.29
Average
40.54±64.10
5.06±3.51
10.38±4.24
*ab-absence of plant at sampling location
*nf-not found (element not found in plant, negative values)
153
250
Concentration
200
150
100
50
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16
Sampling Points
Water (µg/L)
Plant (µg/g)
Sediment (µg/g)
Figure 4.12 Average concentrations of nickel in water, plant and sediment of the
sampling points
The Ni concentration in sediments taken from the river were also determined and
listed in Table 4.19 and shown in Figure 4.12 for the six samplings. The concentrations of
Ni in the sediment taken from the 16 sampling points were ranged from 4.20 µg/g to 17.4
µg/g. The highest average concentration was obtained from sampling point 6 (Kg. Jaya
sepakat) and the lowest concentration was obtained from sampling point 11 (Tampoi). This
is shown in Table 4.19 and Figure 4.12. Meanwhile, the average value of Ni obtained from
the sediment of the Sg. Skudai river system is 10.38 µg/g.
Several previous studies (Table 4.12) indicated that Ni concentrations in
contaminated sediment ranged from 3.68 µg/g to 811 µg/g (Reilly, 1991; Schaller et al.,
1994; Abaychi and Douabul, 1985; Lo and Fung, 1991; Ndiokwere, 1984; Tariq et al.,
1984; Tran Van and Teherani, 1989b). Sediments usually contain 10 µg/g to 1000 µg/g Ni
in the absence of industrial or agricultural contamination (Bowen, 1966). This clearly
shows that the overall Ni concentrations obtained from the sediments of the Sg. Skudai
river system is not polluted.
In terms of Ni, the river waters of Sg. Skudai river system were suitable for the
support of aquatic life and supply water for domestic, industrial and agricultural uses for
the above mentioned samplings and sampling points.
154
4.4.8
Zinc
In this study, concentrations of zinc in water, plant and sediment of the Sg. Skudai
river system were determined for six samplings and the average values are reported in
Table 4.20. Meanwhile, the graphical forms of the result are shown in Figure 4.13. The
average levels of Zn in water samples obtained from the Sg. Skudai river system ranged
from 1.47 µg/L to 212.44 µg/L for the 16 sampling points. The highest level of zinc was
obtained at sampling point 8 (Tmn. Universiti) and the lowest at sampling point 2
(Sengkang). Meanwhile, the average zinc concentration found in this study in the waters of
Sg. Skudai river system is 40.54 µg/L. DOE (2000) reported 0.016 mg/L of zinc in the Sg.
Skudai in year 2000 and 0.0346 mg/L of zinc in year 1999. It seems that the concentration
has increased since then due to pollution loadings into the river.
Studies in several countries reported levels of zinc in water were ranged from 10
000 µg/L to 15 000 µg/L (Reilly, 1991; Tariq et al., 1996; Abaychi and Douabul, 1985;
Inhat et al., 1993; Veado et al., 1997, Polprasert, 1982, Sakai et al., 1986) (Table 4.10).
The recommended INWQS threshold level of zinc for Malaysian rivers is 500 µg/L
(Appendix 2). Thus, the concentration of zinc in all sampling points is within the INWQS
threshold value. Besides that, concentration of zinc in the Sg. Langat was found to be 74
µg/L (M. Shuhaimi Othman and A. R. Nurlailawati, 2004). While Lee et al. (2004)
reported 0.46 to 1.13 µg/L of zinc in Sg. Chuau. Compared to these two studies, the
concentration of zinc in the Sg. Skudai river is very high. At sampling location 8 (Tmn.
Universiti), zinc was reported to be high due to many electroplating industries functioning
there same as the reason given by Rakmi, A. M. and Salmijah, S. (1993) in their study of
heavy metals in wastewaters.
However, the zinc concentration in plants for the 16 sampling points ranged from
351.52 µg/g at sampling point 11 (Tampoi) to 18598.16 µg/g at sampling point 6 (Saleng ).
The average concentration of Zn in plants from the 16 sampling locations are shown in
Table 4.20 and depicted in Figure 4.13. The average level of Zn found in the plants of the
Sg. Skudai river system for the 16 sampling points is 3785.42 µg/g. The concentration of
zinc in plant samples from the Sg. Skudai River system exceeded the DOE Water Quality
Criteria for Malaysia (87.5µg/g) at all sampling points (Appendix 7).
155
Table 4.20 : Average zinc concentration for water, plant and sediment from the Sg. Skudai
river system
Sampling
Point
Water
(µg/L)
Plant
(µg/g)
Sediment
(µg/g)
1
26.99±0.30
10489.00±1.99
29.53±1.28
2
21.06±0.36
1353.04±2.19
24.35±1.06
3
29.18±0.09
3193.94±1.11
52.19±1.08
4
40.40±0.27
807.27±0.17
289.14±1.90
5
41.10±0.20
18598.16±3.19
25.81±1.16
6
34.71±0.33
1075.71±0.58
52.21±1.60
7
25.69±0.08
5451.84±1.25
145.37±1.64
8
77.86±0.27
2517.39±1.12
29.84±0.71
9
64.66±0.71
1513.66±1.51
29.14±1.13
10
31.93±0.38
1323.35±0.15
128.05±1.18
11
82.09±0.44
351.52±2.14
268.06±4.20
12
125.18±1.76
1156.93.16±3.16
674.60±1.84
13
44.07±0.53
ab
374.06±3.44
14
62.50±0.44
1378.96±1.02
1246.94±7.19
15
40.71±1.05
ab
42.90±2.41
16
38.33±0.18
ab
84.73±1.84
Average
49.15±27.32
3785.42±52.19
218.56±32.62
*ab-absence of plant at sampling location
The concentrations of Zn in plants grown on uncontaminated soils is 150 µg/g (Lepp,
1966). Previous studies (Table 4.11) from several countries showed that zinc concentration
in plants from polluted areas were ranged from 1142 µg/g to 15957µg/g (Kanias and
Philianos, 1978; Rodushkin et al., 1999; Miryakova, 1996, Rajurkar and Damame, 1998;
Tran Van and Teherani, 1989a). This shows the plant samples from the Sg. Skudai River
system is highly polluted with zinc. Besides that, Baktini Sawawi (1999) also reported that
the mangrove trees in Sg. Sepang Kecil, Selangor is most polluted with zinc and the
156
concentration that was determined was 67.9 µg/g. But still, compared to Sg. Skudai, that
level of zinc is considered low.
Apparently, the concentrations of Zn in the sediment taken from the 16 sampling
points were ranged from 24.52 µg/g to 12246.94 µg/g. The highest average concentration
was obtained from sampling point 14 (Kg. Tlk. Serdang) and the lowest concentration was
obtained from sampling point 2 (Sengkang). This is shown in Table 4.20 and Figure 4.13.
Meanwhile, the average value of Zn obtained from the sediment of the Sg. Skudai river
system is 218.56 µg/g. Several other studies reported concentration of zinc in sediment
from Kuala Juru 233 µg/g (Mat, I. and Maah, M. J., 1994a). While, sediments from Kuala
Selangor were found to have zinc concentration of 34.0 µg/g (Mat, I. and Maah, M. J.,
Concentration
1994b).
20000
18000
16000
14000
12000
10000
8000
6000
4000
2000
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16
Sampling Points
Water (µg/L)
Plant (µg/g)
Sediment (µg/g)
Figure 4.13: Concentration of zinc in water, plant and sediment of the sampling point
Several previous studies indicated that Zn concentration in sediment ranged from
0.08 µg/g to 4960 µg/g (Reilly, 1991; Abaychi and Douabul, 1985; Lo and Fung, 1991;
Ndiokwere, 1984; Tariq et al., 1984; Polprasert, 1992, Houba et al., 1983, Sakai et al.,
1986, Say et al., 1987 ) (Table 4.12). Sediments usually contain 10 µg/g to 300 µg/g zinc
in the absence of industrial or agricultural contamination (Bowen, 1966). This clearly
shows that the overall Zn concentration obtained from the sediments of the Sg. Skudai
river system is not polluted. In a study, M. Shuhaimi and A. R. Nurlailawati (2004)
reported that 30 µg/g of zinc found in the sediment from the Sg. Langat, Selangor. This
shows clearly that the sediments from the Sg. Skudai is highly polluted with zinc.
157
In terms of Zn, the river waters of Sg. Skudai river system were suitable for the
supply of water for domestic, industrial and agricultural uses for the above mentioned
sampling points. However, due to the high zinc concentration in the plant from the river
system, the health of the aquatic ecosystem of Sg. Skudai river system is under stress and
the river system is unable to provide ecosystem services.
4.5 Trend of Heavy Metal Concentration in Water
The elemental concentrations determined in water for each sampling were
presented in appendix 5. Based on that, the trend of concentration of heavy metals in water
for each of the sampling was presented in Table 4.21 Besides that, the average
concentrations of heavy metals in water for all the sampling points are listed in Table 4.22.
Then trend of heavy metals in water of the Sg.Skudai river system for average elemental
concentration of the sampling points is Zn>Ni>Cu>Cr>As>Pb>Hg>Cd as in Table 4.22.
This results show that zinc is the highest concentration of heavy metal determined in 5
samplings out of 6 samplings, except for sampling 2. Based on the trend of heavy metals
according to average value of all sampling points in Table 4.22, zinc is the highest
concentration of metal among all the sampling points in the Skudai river water. Thus, Zn is
the highest concentration found in the Sg. Skudai river water and cadmium is the lowest
concentration in the Sg. Skudai river water. A study in Sg. Sepang Kecil, Selangor found
that the trend of heavy metal concentration in water is Pb>Zn>Cr>Cu>Cd (Baktini
Sawawi, 1999).
4.6
Trend of Heavy Metal Concentration in Plants
The trend of heavy metal concentration in plants from the Sg. Skudai river system
for each of the sampling were determined and presented in Table 4.23. Besides that, the
average concentrations of heavy metals in plants for all the sampling points are listed in
Table 4.24. The trend of heavy metals in plants of the Sg.Skudai river system for all
sampling points is Zn>Cr>Cu>Pb>Ni>As>Hg>Cd. This shows that zinc is the highest
concentration of heavy metal found in plants determined in all 6 samplings. Based on the
trend of heavy metals according to average value of all sampling points in Table 4.24, also
shows that zinc is the highest concentration of metal found in plants among all the
158
sampling points in the plants from the Sg. Skudai river. The element Zn is the highest
concentration found in the plants from the Sg. Skudai river and Hg is the lowest
concentration found in the plants for all the six samplings. Meanwhile, for all the sampling
points zinc is the highest concentration found in the plants and cadmium is the lowest
concentration found in plants from the Sg. Skudai river system. Another study of heavy
metals in plants indicated a trend of Zn>Pb>Cu>Cd>Cr in the mangrove trees from Sg.
Sepang Kecil, Selangor (Baktini Sawawi, 1999).
Table 4.21 : Trend of heavy metals in water for the six samplings
Sampling
1
2
3
4
5
6
Trend of heavy metals
Zn>Cu>Ni>As>Cr>Pb>Hg>Cd
Ni>Zn>Cu>As>Cr>Pb>Cd>Hg
Zn>Cu>Ni>As>Pb>Cr>Cd>Hg
Zn>Ni>Cu>As>Cr>Pb>Hg, Cd
Zn>Cu>As>Ni>Cr>Pb>Hg>Cd
Zn>Cu>Ni>Cr>As>Pb>Hg>Cd
Table 4.22 : Average heavy metals concentration in water for the six samplings
Elements
As
Cd
Average
9.66
concentrations
0.37
Trend
Zn>
Ni>
Cr
Cu
Hg
16.88
27.48
0.86
Cu>
Cr>
As>
Ni
Pb
Zn
40.54
3.87
49.15
Pb>
Hg>
Cd
Table 4.23: Trend of heavy metals in plants for the six samplings
Sampling
1
2
3
4
5
6
Trend of heavy metals in plants
Zn>Cr>Cu>Pb>Ni>As>Hg>Cd
Zn>Cr>Cu>Pb>Ni>Cd>As>Hg
Zn>Cr>Cu>Ni>Pb>As>Cd>Hg
Zn>Cr>Cu>Ni>Pb>As>Hg>Cd
Zn>Cr>Cu>Ni>Pb>Hg>Cd (As not detected)
Zn>Cu>Cr>Ni>Pb>As>Hg>Cd
159
Table 4.24: Average heavy metals concentration in plants for the six sampling
Elements
As
Cd
Cr
Cu
Hg
Ni
Pb
Zn
Average
concentrations
4.42
0.26
26.46
16.31
0.3
5.06
4.63
3785.41
Trend
Zn>
Cr>
Cu>
Pb>
Ni>
As>
Hg>
Cd.
4.7
Trend of Heavy Metal Concentration in Sediment
The trend of heavy metal concentrations in sediments from the Sg Skudai river
system for each of the sampling were determined and presented in Table 4.25. Besides
that, the average concentrations of heavy metals in sediments for all the sampling points
and the average concentration of heavy metals for the six samplings are listed in Table
4.26. The trend of heavy metals in sediments of the Sg. Skudai river system for average of
the sampling points and all samplings are the same and the sequence is
Zn>Cr>Cu>Pb>Ni>As>Hg. This indicates that zinc is the highest concentration of heavy
metals and mercury is the lowest concentration of heavy metal found in sediments
determined in all 6 samplings and all sampling points. While, Baktini Sawawi (1999)
reported that a trend of Zn>Cu>Pb>Cr>Cd was observed in sediments from Sg. Sepang
Kecil, Selangor.
Table 4.25: Trend of heavy metals in sediments for six samplings
Sampling
1
2
3
4
5
6
Trend of heavy metals in sediment
Zn>Cr>Cu>Pb>As>Ni>Hg>
Zn>Cr>Cu>Pb>Ni>As>Hg>
Zn>Cr>Pb>Cu>As>Ni> (Hg- not detected)
Cr>Zn>Cu>Pb>As>Ni> (Hg-not detected)
Zn>Cr>Pb>Cu>As>Ni> (Hg- not detected)
Cr>Zn>Cu>Ni>As>Pb> (Hg- not detected)
160
Table 4.26: Average heavy metals concentration in sediments for the six sampling
Elements
As
Cr
Cu
Hg
Ni
Pb
Zn
Average
concentrations
9.42
130.57
27.58
1.65
10.38
21.31
218.55
Trend
Zn>
Cr>
Cu>
Pb>
Ni>
As>
Hg
4.8
Plants as Bio-indicators
Metals and refractory organic chemicals, besides their acute toxicity, have the
potential to bioaccumulate in aquatic organisms. This might impose stress on the latter so
reducing their ability to tolerate the natural rigours of the environment; alternatively if
reconcentrated up a food chain they could present a risk to high predators including man.
Indicator organisms have been successfully employed in the assessment of water
pollution in most temperate regions. In Malaysia, the importance of such indicators in
surveillance work has yet to be recognized. Nevertheless, there have been efforts in using
organisms in water pollution assessment. For example, Aspergillus spepens a fungal
spesies, was found to be an indicator of organic enrichment of surface waters in Sg. Klang
and Sg. Gombak (Jangi and Abas, 1979). Low et al. (1984) studied the possibility of using
selected aquatic vascular plants as indicators for heavy metal pollution. Bacteria, besides
being included as one of the parameters monitored by the Department of Environment in
its surveillance programme, are frequently used as indicators of sewage pollution in river
studies such as the Sg. Klang (Law, 1980). Algal studies in Sg. Batang Penar, Negeri
Sembilan were carried out to test the reliability of diatoms as indicators of river pollution
in the tropics (Nather et al., 1986).
The sea is the ultimate ‘sink’ for waste constituents and, industrial and sewage
discharges to river systems is major routes by which these contaminants enter the marine
environment. The level of heavy metals occurring in water, sediment, animals and plants is
currently a cause for concern and the subject of control legislation. The Japanese incidents
of mercury and cadmium poisonings in the 1950s and 1960s, as well as evidence provided
by the presence of polluted crustaceans in the coastal waters of many countries, show that
161
responsible authorities must always be alert to the dangers that necessarily result from our
present industrialization (Greenberg et al., 1979).
Concentrations of metals in water may reflect nearby industrial activity as well as
the composition of local rock and soil nature. Soil is the principal source of the metals we
find in plants. All the nutrients a plant needs for growth with the exception of carbon and
oxygen are drawn from the soil. Plants such as Astralagus, which can tolerate high levels
of metals in the soil and, in many cases accumulate them up to toxic levels, are known as
‘indicator plants’. Seed of most plants, if they fall on soil contaminated with high
concentrations of copper, lead, zinc or other metals, will fail to germinate or, if they do,
will die soon after sprouting. But, because of the great genetic variability that exists among
populations of plants, there will be occasional individuals with the ability to survive and
even prosper in such toxic soil conditions. The resulting plant may not be quite as vigorous
or as well formed as if they were growing on normal uncontaminated soil, but they will
survive and develop, particularly as they do not have to compete for space and nutrients
with other more vigorously growing plants. Extensive studies have been carried out in the
UK on starins of the grasses Agrotis and Festuca which can grow on mine tailings rich in
toxic metals. When grazed by animals these grasses can cause poisoning (Reilly,1991).
Considerably higher levels of lead in food occur as a result of environmental
pollution by industry. Thus many toxic materials accumulate along food-webs. In these
situations the detritivore-decomposer levels are frequently the first to show changes, since
the organic matter and the soil are the ultimate sink for most, including airborne, heavy
metal contamination. By selecting appropriate biological monitors from within an
ecosystem it should be possible to trace any bioaccumulation of metals and to investigate
such effects with time. Plants, which are able to grow on substrates rich in heavy metals,
are generally competitively inferior to non-tolerant plants when grown in noncontaminated soils unless some other environmental stress operates (Klein,1972).
Another study of bio-indicator in Malaysia is copper contents in the roots of
Rhizophora macronata at Sepang – Lukut mangrove forest as reported by Othman et al.
(1995), in this study it was reported that the Rhizophora mucronata is a tolerant plant
spesies towards heavy metals and it accumulates heavy metals in its stems and leaves.
Meanwhile, Hussein et al. (1995) concluded that the weed Axonopus compressus
accumulates lead and cadmium in a high concentration. A research by Ismail et al. (1995),
162
showed that the seaweeds from the Port Dickson sea received heavy metal pollution due to
growth in tourism, shipping, small industries and urbanisation.
Therefore, we had used a aquatic plant (Phragmites karka) in this work to evaluate
if it is suitable to be a bioindicator in the Sg. Skudai river system. Correlation analysis was
conducted on the elemental concentrations of water, plant and sediment for each sampling
and the average concentrations of all sampling points. This correlation studies was also
done to assess the accumulation of heavy metals in sediment. Statistical t-test was also
conducted to show whether the correlation is significant or not significant. The results for
correlation analysis of the elements were listed in Table 4.27. While the results of the
statistical analysis were presented in Appendix 8.
4.8.1
Arsenic
The concentration of arsenic were determined in water, sediment and plants.
Correlation analysis were performed to determine whether the plant can be used as a bioindicator for arsenic and to determine the uptake of the element in plants and sediment.
The correlation coefficient value for arsenic is presented in Table 4.27. It was found that
the correlation coefficient for arsenic in water and sediment is the highest in sampling 6
with r =0.6261. The t-test results in Appendix 8 show a significant relationship between
arsenic in water and arsenic in sediment. Meanwhile, the correlation coefficient for arsenic
in plant and in water ( Cplant- Cwater) and also arsenic in plant and sediment (Cplant-Csedimet),
showed that a good correlation does not exist.
4.8.2
Cadmium
The concentrations of cadmium were determined in water and plants. Correlation
analysis were performed to determine whether the plant can be used as a bio-indicator for
cadmium and to determine the uptake of the element in plants. The correlation coefficient
value for cadmium is presented in Table 4.27. The correlation coefficient for cadmium in
water and plants was not good for all the samplings. The t-test results in all the appendix
shows there is no significant relationship between cadmium in water and in plant.
163
4.8.3
Chromium
Correlation analysis were performed on the results of chromium in water,plants and
sediments to determine whether the plant can be used as a bio-indicator and to determine
the uptake and accumulation of the element in plants and sediment. The correlation
coefficient value for chromium is presented in Table 4.27. It was found that the correlation
coefficient for chromium in plant and water (Cplant-Cwater) is the highest in sampling 2 with
r =0.6564 and also in plant and sediment (Cplant-Csediment) with the r value 0.5555. The t-test
results in Appendix 8 show a significant relationship exists between chromium in water
and in plant and also between chromium in plants and sediment. Meanwhile, the
correlation coefficient for chromium in other samplings does not show a good correlation.
*
*
*
*
*
*
*
-0.1058
0.4277
-0.2347
0.2567
1
2
3
4
5
6
Average
1
2
3
4
5
6
Average
Cplant and Csediment
Cwater and Csediment
* : not determined because insufficient data
0.6261
0.4082
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
1
2
3
4
5
6
Average
Cplant and Cwater
Cd
*
0.3406
*
*
*
0.2527
0.2219
As
*
*
*
*
*
*
*
Sampling
Correlation
-0.0754
-0.0554
0.1905
0.2828
0.5371
-0.055
*
-0.0281
0.5555
-0.1593
0.246
-0.3007
0.2639
0.0739
Correlation
Cr
0.0006
0.6564
0.2458
-0.1233
-0.1633
-0.1837
*
-0.1545
-0.0934
0.0951
0.4693
0.1698
0.589
-0.0238
0.1939
-0.0374
0.0563
-0.3858
-0.3023
0.043
0.1584
Coefficient
Cu
-0.2801
0.6542
0.562
-0.2636
-0.0598
0.3232
0.2789
0.0756
-0.0283
0.1355
-0.1978
*
-0.0625
-0.1028
0.1595
0.1221
*
*
*
-0.3788
0.0117
(r) value
Pb
-0.0311
0.0006
*
*
*
0.0976
-0.0319
*
*
*
*
*
*
*
*
*
*
*
*
*
*
Hg
-0.3174
-0.4109
-0.3283
-0.3059
0.1204
-0.119
*
-0.2086
0.0199
0.1353
0.2778
0.0125
-0.0628
0.2875
*
*
*
-0.01
*
0.1193
-0.4444
Ni
*
*
*
0.027
*
-0.155
0.1462
Table 4.27 : Correlation coefficient (r) value of concentration of heavy metals in plants ,water and sediment
0.3125
-0.0673
0.7693
0.1063
0.6769
-0.0687
0.4741
-0.1692
-0.1506
0.0059
0.6358
0.2071
0.5499
-0.2413
Zn
-0.05
-0.3017
0.0139
0.1056
0.4666
0.1371
-0.2204
165
4.8.4
Copper
The concentrations of copper were obtained from the analysis of water, sediment
and plants from the Sg. Skudai river system. Correlation analyses were performed on the
results and the correlation coefficient value for copper was presented in Table 4.27. It was
found that the correlation coefficient for copper in plant and water (Cplant-Cwater) is the
highest in sampling 2 with r =0.6542 and also in sampling 6 for water and sediment (CwaterCsediment) with the r value 0.5890. The t-test results in Appendix 8 show a significant
relationship exists between copper in water and in plant and also between copper in water
and sediment. The correlation coefficient for copper in other samplings between water,
sediment and plant does not show a good agreement between them.
4.8.5
Lead
The concentrations of lead were determined in water, sediments and plants. The
uptake and accumulation of the element in plants and sediment were determined using the
correlation analysis and also to determine whether the plant can be used as a bio-indicator
for lead. The correlation coefficient value for lead is shown in Table 4.27 for all the
samplings. The correlation coefficient for lead was not good for all the samplings. The ttest results in all the appendix shows there is no significant relationship between lead in
water and in plant. Thus, this plant is not suitable to be a bio-indicator for lead in the Sg.
Skudai river.
4.8.6
Mercury
Mercury concentrations were determined in water, sediments and plants.
Correlation analysis were performed to determine whether the plant can be used as a bioindicator and to determine the uptake of the element and accumulation in plants and
sediment. The correlation coefficient value for mercury is presented in Table 4.27 for all
the samplings. The correlation coefficient for mercury was not good for all the samplings.
The t-test results in all the appendix also shows there is no significant relationship exists
between mercury in water, plant and sediment.
166
4.8.7
Nickel
Nickel concentrations were determined in water, sediments and plants. Correlation
analysis were performed to determine whether the plant can be used as a bio-indicator and
to determine the uptake of nickel in plants and sediment. The correlation coefficient value
for nickel was not good and very low correlation exists as presented in Table 4.27 for all
the samplings. The t-test results in the appendix also show there is no significant
relationship between nickel in water, plant and sediment.
4.8.8
Zinc
The concentration of zinc was determined in water, sediment and plants.
Correlation analysis were performed to determine whether the plant can be used as a bioindicator and to determine the uptake of the element in plants and sediment. The
correlation coefficient value for zinc is presented in Table 4.27. It was found that the
correlation coefficient for zinc in water and sediment (Cwater-Csediment) was very good in
sampling 5 with r =0.6769. The t-test results in Appendix 8 show a significant relationship
exists between zinc in water and in sediment. Meanwhile, the correlation coefficient for
zinc in other sampling did not show a good correlation. This shows that the accumulation
of zinc in water can be observed in the sediments too.
4.8.9
Overall Discussion on Correlation Analysis
On the whole, we can conclude that a good correlation exist for chromium and
copper in correlation analysis between plant and water and plant and sediment. This shows
that this plant is suitable and has the potential to be a bio-indicator for chromium and
copper in the Sg. Skudai river. Meanwhile, arsenic and zinc showed a good correlation in
water and sediment. Therefore, we can conclude that sediment accumulation is significant
for these two elements in the river. On the contrary, other elements such as Cd, Pb, Hg and
Ni did not show any correlation exist in the correlation analysis that was performed on the
results for water, plant and sediment.
170
REFERENCES
Abaychi, J. K., and Douabul, A. A. Z. (1985).Trace Metals in Shatt Al-Arab River, Iraq.
Water. Res.. 19: 457-462.
Adriano, D. C. (1986). Trace Elements In The Terrestrial Environment. New
York.:Springer Verlag.
Ahmad Azly (1988). Rumpai (Panduan Berilustrasi). Kuala Lumpur: Dewan Bahasa
dan Pustaka. 79
Alfassi, Z. B. (1994). Determinations of Trace Elements. Weinheim. Balaban
Publishers. VCH.
Allaway, W. H. (1968). Agronomics Controls Over the Environmental Cycling of Trace
Elements. Adv. Agron. 20: 74-235.
Alloway, B. J. and Ayres, D. C. (1993). Chemical Principles of Environmental
Pollution. Great Britain: Blackie Academic & Professional.
Aziz, J. (1983). Determination of Water Quality Changes from River to Treatment Plant
to Consumers: A case study at Sungai Langat, Ulu Langat, Selangor. Universiti
Pertanian Malaysia, Serdang, Selangor. A project report, submitted in partial fulfillment
of the requirement for the degree of Bachelor of Science (Environmental Studies) in the
Faculty of Science and Environmental studies.
Baktini Sawawi (1999). Penumpukan Logam Berat Pada Sedimen, Air Dan Pokok
Bakau Rhizophora Mucronata Lam. Di Sungai Sepang Kecil, Selangor. Universiti
Kebangsaan Malaysia: Tesis Sarjana Pengurusan Persekitaran.
171
Bais, V. S., Sen, U. S. and Yatheesh, S. The Zooplankton of the Straw-board Mill
Effluent Mixing Zone in Comparison with a Reference and Diluted Zones of River
Dhasan, Madhya Pradesh. In: V.S. Bais and U.S. Gupta. Environment and Pollution”
New Delhi: Northern Book Center. 12-21. 1991.
Beckett, V. V. A., Pascual. C.B., Kwan. C.S. and Beckett, R. (1991). Levels and
Distribution of Trace Metals in Sediments of Laguna Lake (Philippines) and its
Tributary Rivers. Intern. J. Environ. Anal. Chem. 45: 101-116
Bishop, M. (1971). A Chemical and Biological Survey of the Gombak River. Kuala
Lumpur. Malaysia.
Brookes, R. R. (1987). Serpentine and Its Vegetation. London. Croom Helm.
Bowen, H. J. M. (1966). Trace Elements in Biochemistry. New York: Academic Press.
Burrel, D. C. (1974). Atomic Spectroscopic Analysis of Heavy Metal Pollutants in
Water. U.S.A: Ann Arbour Science.
Chapman, D. (1992). Water Quality Assessments. A Guide to The Use of Biota,
Sediments and Water in Environmental Monitoring. London, U.K.:Chapman and Hall
Ltd.
Chen, C. S. and Jiang, S. J. (1996). Determination of As, Sb, Bi and Hg in Water
Samples by Flow Injection Inductively Coupled Plasma Mass Spectrometry With An
In-Situ Nebulizer/Hydride Generator. Spectrocimica Acta. 51B: 1813-1821.
Clapham, W.B. Jr. (1983). Natural Ecosystems. 2nd.ed. New York: Macmillan.
Connel, D. W. and Milleer, G. J. (1984). Chemistry and Ecotoxilogy of Pollution. New
York: John Wiley & Sons.
Consumers Association of Penang – Sahabat Alam Malaysia (1996). State of the
Malaysian Environment. Penang. Consumers Association of Penang. 53
172
Cook, C. D. K. (1990). Aquatic Plant Book. Netherlands: SPB Academic Publishing.
164.
Crain, J. and Kiely, J. T. (1996). Waste Reduction in Inductively Coupled Plasma Mass
Spectrometry Using Flow Injection and a Direct Injection Nebulizer. J. Anal. At.
Spectrometry. 11: 525-527.
Cullen, W. R. and Dodd, M. (1989). Arsenic Speciation in Clams of British Columbia.
Applied Organometallic Chemistry. 3: 68-79.
Date, A. R. and Gray, A. L. (1989). Applications of Inductively Coupled Plasma Mass
Spectrometry. Great Britain: Blackie Academic and Professional.
Director of National Mapping (1997).Kulai, Skudai, Johor Bahru. Malaysia:Peta
Department of Environment (DOE), Ministry of Science, Technology and Environment,
Malaysia. (1985). Water Pollution and Its Control in Malaysia. Kuala Lumpur: Not
Published.
Department of Environment (DOE), Ministry of Science, Technology and Environment,
Malaysia. (1986a). Water Quality Criteria and Standards for Malaysia : Criteria and
Standards for Inorganic Constituents and Radionuclides.Kuala Lumpur: Volume 2: Part
1.
Department of Environment (DOE), Ministry of Science, Technology and Environment,
Malaysia. (1986b). Water Quality Criteria and Standards for Malaysia: Criteria and
Standards for Inorganic Constituents and Radionuclides. Kuala Lumpur: Volume 2:
Part 2.
Department of Environment (DOE), Ministry of Science, Technology and Environment,
Malaysia. (1986). Environmental Quality Report, 1985. Kuala Lumpur.
Department of Environment (DOE), Ministry of Science, Technology and Environment,
Malaysia. (1993). Environmental Quality Report, 1993. Kuala Lumpur.
173
Department of Environment (DOE), Ministry of Science, Technology and Environment,
Malaysia. (1994). Water Pollution Control in the Upper Langat River Basin. Selangor,
Malaysia. Kuala Lumpur.
Department of Environment (DOE), Ministry of Science, Technology and Environment,
Malaysia. (1996). Environmental Quality Report, 1996. Kuala Lumpur.
Department of Environment (DOE), Ministry of Science, Technology and Environment,
Malaysia. (1998). Classifications of Malaysian Rivers. Kuala Lumpur.
Department of Environment (DOE), Ministry of Science, Technology and Environment,
Malaysia. (1999). Environmental Quality Report, 1999. Kuala Lumpur.
Department of Environment (DOE). Ministry of, Natural Resources and the
Environment, Malaysia. (2000). Environmental Quality Data, 1995-2000. Kuala
Lumpur.
Department of Environment (DOE). Ministry of Natural Resources and the
Environment, Malaysia. (2002). Annual Report, 2002. Kuala Lumpur.
Department of Environment (DOE). Ministry of, Natural Resources and the
Environment, Malaysia. (2003a). Annual Report, 2003. Kuala Lumpur.
Department of Environment (DOE). Ministry of, Natural Resources and the
Environment, Malaysia. (2003b). Environmental Quality Report, 2003. Kuala Lumpur.
Department of Irrigation and Drainage (DID), Malaysian Tourism Promotion Board,
Malaysia Airline System. (1992). “Rivers of Malaysia.” Selangor: Design Dimension.
Department of Metereological Services. (DMS). (1999). Metereological Data of Skudai
River Basin. (1998-1999). Department of Metereological Services, Petaling Jaya,
Malaysia.
Devendra Swaroop Bhargava. (1983). Use of Water Quality Index for River
Classification and Zoning of Ganga River. Environmental Pollution (Series B).6: 51-67.
174
Dixit, S.S. and Witcomb, D. (1983). Heavy Metal Burden in Water, Substrate and
Microinvertebrate Body Tissue of a Polluted River Irwell (England). Environmental
Pollution (Series B). 6: 161-172.
Edwards, T. K. (1993). Assessment of Surface Water Quality and Water Quality Control
Alternatives, Johnson Creek Basin, Oregon. USA: US Geological Survey, Earth
Science Information Services.
Eisler, R. (1981). Trace Metal Concentrations in Marine Organisms. Oxford: Pergamon
Press.
Environmental Protection Society Selangor. (1975). A Study of the Extent of Pollution
of the Sg. Kelang and Its Tributaries. Alam Sekitar.1: 21.
Erdawati. Kajian Penspesiesan dan Penentuan Ketoksikan Logam Aluminum, Kuprum
dan Zink Dalam Larutan Akues. Tesis Ijazah Doktor Falsafah (Kimia). Universiti
Kebangsaan Malaysia. 1997.
Forstner-Wittman. (1981). Metal Pollution in the Aquatic Environment. 2nd.ed.
Germany: Spriger-Verlag Berlin Hiedelberg.
Fowler, B. A. (1983). Biological and Environmental Effects of Arsenic. Amsterdam:
Elsevier.
Giddings, J.C. (1973). Chemistry, Man, and Environmental Change: An Integrated
Approach. USA: Canfield.
Gray, A. L. (1989). The Origins, Realization and Performance of ICP-MS systems. In.
Date, A. R. and Gray, A. L. Applications of Inductively Coupled Plasma Mass
Spectrometry. Great Britain: Blackie Academic and Professional.
Greenberg. M. R., Belnay, G., Cesanek, W., Neuman, N., Shepherd, G. (1979). A
Primer on Industrial Environmental Impact. USA: Center for Urban Policy Research.
175
Greenfield, S., Jones, I. L. and Berry, C. T. (1964). High Pressure Plasma as
Spectroscope Emission Sources.Analyst. 89: 713-720.
Gomez, N. (1999). Epipelic Diatom from Matanza- Riachuelo River (Argentina), a
Highly Polluted Basin from the Pampean Plain: Biotic Indices and Multivariate
Analysis. Aquatic ecosystem Health and Management. 2: 301-309.
Goulden, P.D. (1978). Environmental Pollution Analysis. Great Britain: Heyden and
Son Ltd.
Gulati, R. D. (1987). Concept of Ecosystem Stress and Its Assessment. In.
Ravera.O. Ecological Assessment of Environmental Degradation, Pollution and
Recovery. Amsterdam: Elsevier Science.
Haissinsky, M. and Adloff, J.P. (1965). Radiochemical Survey of the Elements:
Principal Characteristics and Applications of the Elements and Their Isotopes.
Amsterdam: Elsevier.
Hall, J. A and Morrison, J.W. (1978). Environmental Studies: A Field and Laboratory
Approach. 2nd.ed. New York: Arco.
Hamilton, J. W. and Wetterhahn, K. E. (1988). Chromium. In. Seiler, G. H. and Sigel,
H. Handbook on Toxicity of Inorganic Compounds. New York: Marcel Dekker, Inc.
Hans, G.S., Astrid, S. and Helmut S. (1994). Handbook on Metals in Clinical and
Analytical Chemistry. New York: Marcel Dekker Incorporated.
Harrison, R. M. (1992). Understanding Our Environment: An Introduction to
Environmental Chemistry and Pollution. 2nd.ed. Northamptonshire: Royal Society of
Chemistry.
Harrison, R. M. (1996). Pollution: Causes, Effects and Control. Cambridge: Royal
Society of Chemistry.
176
Hashim Baharin (1992). Daun Angsana (Pterocarpus indicus) Sebagai Penunjuk Bio –
Semulajadi Pencemaran Udara. Universiti Teknologi Malaysia. Tesis Sarjana Muda
Sains Industri (Kimia).
Herber, R. F.M. (1994). Cadmium. In. Handbook on Metals in Clinical and Analytical
Chemistry. New York: Marcel Dekker Incorporated.
Herold, D. A. and Fitzgerald, Robert, L. (1994). Chromium. In. Seiler, H. G., Sigel, A.
and Sigel, H. (1994). Handbook of Metals in Clinical and Analytical Chemistry.New
York: Marcel Dekker Inc.
Hester, R.E. (1983). Industry And The Environment in Perspective. Great Britain:
Whitstable Litho Ltd.
Houba, C., Remacle, J., Dubois, D. and Thorez, J. (1983). Factors Affecting the
Concentrations of Cadmium, Zinc, Copper and Lead in the Sediments of the Vesdre
River. Water Resources. 17(10): 1281-1286.
Hussien, K., Yean, L. S., Mushrifah, I and Mat Sani. (1995). Studies on the Effects of
Air pollution on Axonopus compressus in Kuala Lumpur and Petaling Jaya. Prosiding
UKM. Bangi. Universiti Kebangsaan Malaysia. 191-196.
IAEA.(1990). Practical Aspects of Operating A Neutron Activation Analysis
Laboratory.Vienna: IAEA.
Indah Water Konsortium, (IWK). List of Sewage Treatment Plants in the Langat River
Basin. Indah Water Konsortium, Shah Alam Unit, Klang Unit and Pantai Dalam Unit.
Malaysia. 2000.
Inhat, M., Gamble, D.S., Gilchrist, F. R.( 1993). Determination of Trace Element Levels
in Natural Fresh Water by Inductively Coupled Plasma Mass Spectrometry. Intern. J.
Environ. Anal. Chem.53: 63-78.
Ismail, A., Kassim, N. and Abu Bakar, B. (1995). Levels of Trace Metals (Cu, Cd, Pb
and Zn) in Some Seaweeds of Port Dickson, Malaysia. Prosiding ke-5 Universiti
Kebangsaan Malaysia. UKM, Bangi. 23-26.
177
Iqbal, M. Z., and Qadin, M. A. (1989). Determination of Hg, Co, Cr, Zn and Fe in
Various Plant Leaves Using Neutron Activation Analysis. Elsevier Sequoia S.A.
Lausanne Akedemiai Kiado.14: 35-45.
Jackson, A.R. W and Jackson, J. M. (1996). Environmental Science: The Natural
Environment and Human Impact. England: Longman Group Limited.
Jaleel Tariq, M. Ashraf, M. Jaffar, M. Afzal.(1996). Pollution Status of The Indus
River, Pakistan, Through Heavy Metal and Macronutrient Contents of Fish, Sediment
and Water. Water Resources. 30 (6):1337-1344.
Jangi, M. S. and M. A. Abas. (1979). Aquaspirillum sperspens: A Good Indicator
Organisms for Organic Enrichment of Surface Waters. Proceeding of the International
Conference on “Trends in Applied Biology in Southeast Asia”. Penang. Institut Alam
Sekitar dan Pembangunan. 137-139.
Jeffree Mohamed (1993). Taburan Logam Berat Di Muara Sungai Kajian Kes: Sungai
Skudai Dan Pantai Lido. Universiti Teknologi Malaysia: Tesis Sarjana Muda Sains
Industri (Kimia).
Joy, C.M., Balakrishnan, K. P. and Ammini Joseph, (1990) Effect of Industrial
Discharges on the Ecology of Phytoplankton Production in the River Periyar (India).
Water Resources. 24(6): 787-796.
Kadaruddin, A. (2000). Pencemaran Air dan Pengurusannya di Malaysia: Cabaran Alaf
Baru. Dlm. Jamaluddin Md. Jahi. Pengurusan Persekitaran di Malaysia: Isu dan
Cabaran. Bangi: Universiti Kebangsaan Malaysia. 104 126.
Kadir Jaafar (2002). Kajian Kes Sungai Segget Johor Bharu. Universiti Kebangsaan
Malaysia: Tesis Sarjana Pengurusan Persekitaran.
Kanias, G. D. and Philianos, S.M. (1978). Determination of Trace Elements in a
Medicinal Plant by Neutron Activation Analysis. Journal of Radioanalytical Chemistry
.46: 87-93.
178
Karr, J. R. (1995). Using Biological Criteria to Protect Ecological Health. In. Rapport,
D.J., Gaudet, C.L and Calaow,P. Evaluating and Monitoring the Health of Large-Scale
Ecosystems. Springer Press: Germany.
Kashin, V. K. and Ivanov, G. M. (1994). Nickel in Natural Waters of Transbaikalia.
Water Resources. 24 (3): 311-314.
Klein, L. (1972). Aspects of River Pollution. London :Butterworths Scientific
Publications.
Kress, J., De Fillipps, R. A., Far, E. and Daw Yin Yin Kyi. (2003). A Checklist of the
Trees, Shrubs, Herbs and Climbers of Myanmar. Washington, D. C. : The United States
Department of Agriculture. 110-112.
Kruger, P. (1971). Principles of Activation Analysis. USA: John Wiley & Sons, Inc.
Kudo, A., (1992). Natural and Artificial Mercury Decontamination-Ottawa River and
Minamata Bay (Yatshushiro Sea). Wat. Sci. Tech. 26(1-2): 217-226.
Law, E. A. (1981). Aquatic Pollution. New York: John Wiley & Sons.
Law, A. T. and Singh, (1981). A. Distribution of Manganese, Iron, Copper, Lead and
Zinc in Water and Sediment of Kelang Estuary. Pertanika. 9(2): 209-217.
Law, A. T. (1980). Sewage Pollution of Kelang River and its Estuary. Pertanika. 3 (1):
13-19.
Lederer, W.H. and Fensterheim, R.J. (1984). Arsenic: Industrial,
Biomedical,Environmental Perspectives. New York: Van Nostrand Reinhold Company.
Lee, Choon Woi (1999). Pencemaran Logam Berat Dalam Persekitaran Akuatik: Satu
Kajian Kes di Sg. Juru. Universiti Kebangsaan Malaysia. Tesis Sarjana Pengurusan
Persekitaran.
179
Lee, Yook Heng, Nurul Izzah Ahmad, Ng, Shek Fung, Siti Fatimah Daud, Tan, Keai
Fong, Stephen Ambu. (2000). The Level Of Several Toxic Substances In The Semenyih
River, Selangor. Prosiding Symposium Penyelidikan Ekosistem Lembangan Langat II.
5- 6 Jun. Selangor: Institut Alam Sekitar dan Pembangunan. 5-10.
Lee, Yook Heng, Shahril Mohd. Hussain, Md Fauzan Hj Yapandi, Haw, Pei Fen, Khoo,
Beng Chow. The Content of Some Metals In The River Tributaries From The
Catchment Of Putrajaya Wetlands. Malaysian Journal of Analytical Sciences. 2004;
8(1): 20-25
Legal Research Board. (1997). Food Act 1983 (Act 281) and Regulations.Selangor,
Malaysia: International Law Book Services.
Lewis, E. A. (1981). Aquatic Pollution. New York: John Wiley & Sons.
Lepp, N.W. (1981a). Effect of Heavy Metal Pollution on Plants. Volume 1. London:
Applied Science Publishers.
Lepp, N.W. (1981b). Effect of Heavy Metal Pollution on Plants. Volume 2. London:
Applied Science Publishers.
Lim, W. H., Kho, B. L., Tay, T.H. and Low, W.L. (1998). Plants of Putrajaya
Wetlands. Perbadanan Putrajaya and Putrajaya Holdings, Selangor.
Lo, C. K., Fung, Y. S. (1991). Recovery of Heavy Metals From Acid digestion of an
Estuarine Sediment and Concentration Profiles of Sediment Cores from Hebe Haven
and Ngau Mei Hoi, Hong Kong. Intern. J. Environ. Anal. Chem. 45: 277-291.
Loppi, S., Chiti, F., Corsini, A and Bernardi, L. (1994). Lichen Biomonitoring of Trace
Metals in the Pistoia Area (Central Northern Italy). Environmental Monitoring
Assessment. 29: 17-27.
Low, K. S., C. K. Lee and S. H. Tan. (1984). Selected Aquatic Vascular Plants as
Biological Indicators of Heavy Metals Pollution. Pertanika. 7(1): 33-48.
180
Lozak. A., Soltyk. K., Ostapezuk. P., Fijalek. Z. (2001). Determination of Selected
Trace Elements in Herbs and Their Infusions. Science of the Total Environment. 14: 18.
Lyon, W.S. (1972). Guide To Activation Analysis. New York: Robert E. Krieger
Publishing Company.
M. Shuhaimi Othman and A. R. Nurlailawati. Kajian Kandungan Logam Berat (Cu, Cd,
Zn dan Pb) Di Dalam Air, Sedimen dan Udang Air Tawar Macrobrachium sp. Di Sg.
Langat, Selangor. Malaysian Journal of Analytical Sciences. 2004; 8(1): 20-25
M. Ahmad Badri. (1988).Heavy Metals Pollution in the Urban Environment. In. Sham
Sani and M. Ahmad Badri. Environmental Monitoring and Assessment: Tropical Urban
Applications. Bangi:Universiti Kebangsaan Malaysia.
Maheswaran, A. (1979). Regulatory Measures and Programmes for Water Pollution
Control in Malaysia. Symposium on Recent Development in Effluent Treatment
Technology. June 1979. Malaysia. Universiti Sains Malaysia. 20-26.
Maketab bin Mohamed. (1993). Problems in the Management of Rivers for Drinking
Water Supply: Case Studies. Proc.of the International Symposium Management of
Rivers For The Future, Kuala Lumpur: Department of Irrigation and Drainage (DID).
Mat, I. and Maah, M. J. (1994a). Sediment Trace Metal Concentrations From The
Mudflats Of Kuala Juru and Kuala Muda Of Malaysia. Bulletin of Environmental
Contamination And Toxicology. 53 (5): 740-746.
Mat, I. and Maah, M. J. (1994b). An Assessment Of Trace Metal Pollution In The
Mudflats Of Kuala Selangor And Batu Kawan, Malaysia. Marine Pollution Bulletin. 28
(8): 512-514..
Matthews, R. A., Buikema. A. L., Cairns, J. and Rodgers, J.H. (1982). Biological
Monitoring : Receiving System Functional Methods, Relationships and Indices. Water
Research.16:129-139.
181
Marin, B., Valladon, M., and Monaco, A. (1997). Repducibility Testing of a Sequential
Extraction Scheme for the Determination of Trace Metal Speciation in a Marine
Reference Sediment by Inductively Coupled Plasma-Mass Spectrometry. Analytica
Chimica Acta. 342: 91-112.
Mason, B. and Moore, C. B. (1982). Principles of Geochemistry. 4th . New York: John
Wiley & Sons.
Mazlin, B. M., Hassan, B. B., Chia, J. P. (1999). Pemonitoran Kualiti Air Kolam
Pengoksidaan Kumbahan UKM, Bangi Yang Mengalirkan Efluen ke Sg. Langat..
Proceeding of the 1999 Langat Basin Research Symposium. 7-8 Julai.
Malaysia:LESTARI UKM. 198-212.
Md. Rozali Othman, Abdullah Samad, Suah Pech Cheng, Lee Siew Booi And Elley
Rohaida. (1999). Kualiti Air Sungai Semenyih Dan Anak Sungainya. Proceeding of the
1999 Langat Basin Research Symposium. 7-8 Julai. Malaysia:LESTARI UKM. 212214.
McCaull, J., Crossland, J. (1974). River Pollution. In. Commoner, B. Water Pollution.
USA: Harcourt Brace Jovanovich.
Meybeck, M., Chapman, D.V., Helmer, R. (1989). Global Freshwater Quality: A First
Assessment.”,Great Britain: Alden.
Muhammad Abu Yusuf, Mohd. Nordin Hj Hassan and Md. Pauzi Adullah. (1999).
River Water Quality Assessment And Ecosystem Health: Langat Basin, Selangor.
Proceeding of the 1999 Langat Basin Research Symposium. 7-8 Julai.
Malaysia:LESTARI UKM. 171-188.
Miryakova, T.F. (1996). Heavy Metals in Macrophytes of the Rybinskoe Reservoir.
Water Resources. 23(2): 213-219.
M. Nordin., L. A. Azrina. (1998). Training and Research For Measuring and
Monitoring Ecosystem Health of a Large-Scale ecosystem: The Langat Basin, Selangor,
Malaysia. Ecosystem Health. 4(3): 188-190.
182
Mizuike, A. (1983). Environmental Techniques for Inorganic Trace Analysis. Germany
: Springer-Verlag.
Monteiro, T. M., Oliveira, R., Val, C. 1995). Metal Stress On the Plankton
Communities of Sado River (Portugal). Water Research. 14: 695-700.
Nather Khan, I. S. A., R. P. Lim and M. Ratnasabapathy. (1986). Changes in River
Diatom Community Structure Due to Natural Rubber Effluent. Malaysian J. Sci. 8: 8589.
Ndiokwere, C. L. (1984). An Investigation of The Heavy Metal Content of Sediments
and Algae From The River Niger and Nigerian Atlantic Coastal Waters. Environmental
Pollution (Series B).7: 247-254.
Nia, H. and Houk, R. S. (1996). Fundamental Aspects of Iion Extraction in Inductively
Coupled Plasma Mass Spectrometry. Spectrochimica Acta. 51B: 779-815.
Nriagu, J. O. (1979). Copper In the Environment, Part 1 and 2. Chichester: John Wiley
& Sons Inc.
Othman, S.B., Ijima, K., Zakaria Sulaiman and Mohd. Razali Salam. (1995). Copper
Contents in the Roots of Rhizophora mucronata at Sepang – Lukut Mangrove Forest.
Laporan IRPA 4-07-03-06, Universiti Kebangsaan Malaysia, Bangi, Selangor.
Palmer, K. (1995). An Overview of Potential Environmental Impact from Industrial
Activity.In. Freeman, H.M. Industrial Pollution Prevention. USA: McGraw-Hill.
Parry, S.J. (1991). Activation Spectrometry in Chemical Analysis. USA: John Wiley &
Sons. Inc.
Philips, D. J..H, (1990). Arsenic in Aquatic Organisms: a Review, Emphasizing
Chemical Speciation. Aquatic Toxicology, 16: 151-186.
Petersen, S. L., Larsen, E. H., Larsen, P. B. and Bruun, P. (2002). Uptake of Trace
Elements and PAHs by Fruit and Vegetables from Contaminated Soils. Environ. Sci.
Technol. 36 (14): 3057-3063.
183
Polprasert, C. (1982). Heavy Metal Pollution in the Chao Phraya River Estuary,
Thailand. Water Resources, 16: 775-784.
Rajurkar, N. S. and Damame, M.M.(1998). Mineral Content of Medicinal Plants Used
in The Treatment of Diseases Resulting From Urinary Tract Disorders. Appl. Radiat.
Isot. 49(7): (773-776).
Rakmi, A. M. and Salmijah, S. (1993). Metal Finishing Wastewater: Characteristics
And Minimisation. Kuala Lumpur: Ministry of Science, Technology and the
Environment. 3-7.
Reilly.C. (1991). Metal Contamination of Food. London: Elsevier Applied Science. 310.
Rodushkin, A., Ruth, T., Huhtasaari, A. ( 1999). Comparison of Two Digestion
Methods For Elemental Determinations in Plant Material by ICP Techniques. Analytica
Chimica Acta. 378 :191-200.
Safronova, N. S., Venitsianov, E. V., Ershova, Yu, E., Kocharyan, A. G., Seren’ kaya,
E. P., Zhil’tsova, L.I., Avgul, T. V., Akhmanova, M. V., Bannykh, L.N., Kolotilina, N.
K., Sedykh, E. M., Stashinova, N. P., Dubinchuk, V.T. (1997). Analaytical Methods for
Determining The Content and Forms of Heavy Metals in Natural Water Bodies. Water
Resources. 24(4) :439-447.
Salgare, S.A. (1991). Heavy Metal Pollution. In. V.S. Bais and U.S. Gupta.
Environment and Pollution. New Delhi: Northern Book Center.
Sakai, H., Kojima, Y., Saito, K. (1986). Distribution of Heavy Metals in Water and
Sieved Sediments in the Toyohira River. Water Resources. 20 (5): 559-567.
Sakino, H., Hashimoto, A., Uchimura, Y., Tateishi, S., Akiyama, T., (1980). Note on
Heavy Metal Concentrations in the Aquatic Environment of the Kitakyushu District in
Japan, 1976-1977.Water Research. 14:1233-1237.
Sandberg and Allen. (1981). Metalloids. In: Lepp, N. W. Effect of Heavy Metal
Pollution on Plants. London: Applied Science Publishers.
184
Say, P. J., Harding, P. C. and Whitton, B. A. (1981). Aquatic Mosses as Monitors of
Heavy Metal Contamination in the River Etherow, Great Britain. Environmental
Pollution (Series B).2: 295-307.
Sax, N. I. (1974). Industrial Pollution. New York:Van Nostrand Reinhold Company.
Singhal, R. N. and Jain, M. (1997). Cadmium Induced Changes in the Histology of
Kidneys in Common Carp, Cyprinus carpio (Cyperinidae). Bull. Environ. Contam.
Toxicol. 58: 456-462.
Seaborg, C. T. (1980.) In. Neely, W. Brock, Chemicals in the Environment:
Distribution, Transport, Fate, Analysis. New York: Marcel Dekker.
Seiler, H. G., Sigel, A. and Sigel, H. (1994). Handbook of Metals in Clinical and
Analytical Chemistry. NewYork: Marcel Dekker Inc.
Sittig, M. (1979). Toxic Metals Pollution Control and Worker Protection. Port Ridge,
New Jersey, USA: Nayes Data Corporation.
Solomons, N. W. and Cousins, R.J. (1984). Zinc. In. Prasad, A.S., Alan, R.L.
Absorption and Malabsorption of Mineral Nutriens. New York.
Stoeppler, M. (1992). Hazardous Metals in the Environment. Amsterdam: Elsevier.
Stokes, P. M. and Dreier, S. I. (1983). Mercury Accumulation by Filamentous Algae: A
Promising Biological Monitoring System for Methyl Mercury in Acid Stressed Lakes.
Environmental Pollution (Series B). 5: 255-271.
Sarmani, S. (1985). Determination of Heavy Metals in Water, Suspended Materials and
Sediment from Langat River, Malaysia. Hydrobiologia. 14: 233-238.
Taylor, H.E. (1989). Water Resources. In. Date, A. R. and Gray, A. L. Applications of
Inductively Coupled Plasma Mass Spectrometry. Great Britain: Blackie Academic and
Professional.
185
Tsuchiya, K. (1979). Lead. In. Friberg, L., Nurberg, G. F. and Vouk, V.B. Handbook on
the Toxicology of Metals. Amsterdam: Elsevier.
Tran Van, L and Teherani, D. K. (1988). Determinations of Au, Sb, As, Br, Na, K, Cd,
Mn and Cl in Rice from Vietnam by NAA. J. Radioanal. Nucl. Chem. 128(1): 43-51.
Tran Van, L and Teherani, D. K. (1989a ). Determination of Trace Elements In
Biological Material by NAA. J. Radioanal. Nucl. Chem. 135(6): 443-448.
Tran Van, L and Teherani, D. K. (1989b). Determination of Trace Elements and Heavy
Metals in a Sediment by NAA. J. Radioanal. Nucl. Chem. 135(6): 435-441.
Townsend, A. (1995). Encyclopedia of Analytical Science. London: Academic Press
Limited.
Universiti Kebangsaan Malaysia (UKM). (1996) Detailed Environmental Impact
Assessment for the Proposed KL Linear City Development. Vo1. Main Report.
Bureau of Consultancy and Innovation, Universiti Kebangsaan Malaysia
UKM - DOE. 2000. Projek Pengawasan Biologi dan Indicator Biologi. Bureau of
Consultancy and Innovation, Universiti Kebangsaan Malaysia - Department of
Environment (UKM-DOE), Malaysia.
United States Environmental Protection Agency (USEPA). (1992). Methods For the
Determination of Metals in Environmental Samples. United States Of America: CRC
Press, Inc.
Ure, A. M., and Berrow, M. L. (1982). Chemical Speciation in the Environment in
Environmental Chemistry. Vol. 2, London :Royal Society of Chemistry.
USEPA. (1986). Quality Criteria For Water 1986 (‘Gold Book’). Office of Water
Regulations and Standards, EPA-440/5-86-001 Washington, D.C.
Vernes, A.W. (1997). Inductively Coupled Plasma Mass Spectrometry. In. Settle, F.A.
Handbook of Instrumental Techniques for Analytical Chemistry.Upper-Saddle New
Jersey: Prentice Hall.
186
Veado, M.A. R. V., Pinte, G., Oliveira, A.H., Revel,G. (1997). Application of
Instrumental Neutron Activation Analysis and Inductively Coupled Plasma-Mass
Spectrometry to Studying the River Pollution in the State of Minas Gerais. Journal of
Radioanalytical and Nuclear Chemistry. 17 (1):101-106.
Wandan, E. N. and Zabik, M. J. (1996). Assessment of Surface Water Quality in Cote
d’ Ivoire. Bull. Environ. Contam. Toxicol. 56: 73-79.
Ward, N. I. (1989). Environmental Analysis Using ICP-MS. In. Date, A. R. and Gray,
A. L. Applications of Inductively Coupled Plasma Mass Spectrometry. Great Britain:
Blackie Academic and Professional.
Weber, C.I. (1981). Evaluation of the Effects of Effluents on Aquatic Life in Receiving
Waters- An Overview. In. Bates, J.M. and Weber, C.I. Ecological Assessments Of
Effluent Impacts On Communities Of Indigenous Aquatic Organisms. Great Britain:
Blackie Academic and Professional.
Wendt and Fassel (1965).Inductively-Coupled Plasma Spectrometric Excitation.” Anal
Chem. 53: 920-922.
Wollast, R. (1982). Methodology of Research in Micropollutants- Heavy Metals. Wat.
Sci. Tech. 14:107-125.
Yusof, A.M., Ikhsan, Z. B. and Wood, A. K. (1994). The Speciation of Arsenic in
Seawater and Marine species. J. Radioanal. Nucl. Chem. Articles. 179(2): 277-283.
Yusof, A. M., Wood, A. K. H. and Ahmad, Z. (1995). Marine Sediments Analysis By
the Elemental Rationing Technique. Nuclear Instruments and Methods in Physics
Research B. 99: 502-504
Yusof Samiullah. (1988). Pollutant Exposure Pathways. In. Sham Sani and M. Ahmad
Badri. Environmental Monitoring and Assessment: Tropical Urban
Applications.Bangi:Universiti Kebangsaan Malaysia.