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Ammoniacal Nitrogen

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AMMONIACAL NITROGEN
Course Number and Name
CMT 570 ENVIRONMENTAL POLLUTION LABORATORY
Semester and Year
SEMESTAR 3 YEAR 2
Name of Student:
MOHAMMAD AMIRUL ALIFF BIN
MAHAZAM (2018403148)
Name of Lab Instructor
Dr Shariff Che Ibrahim
Date of Report Submitted
30.06.2019
1.
2.
Name of Group Members
MUHAMMAD SYAZWAN
AZHAR
BIN
MUHAMMAD SYAFIQ AKMAL
BIN ZAMRI
Grade:
1. ABSTRACT
Ammoniacal nitrogen (NH3) in the experiment, is the determination for the
concentration of ammonia, a toxic pollutants in the given water sample. The
measurement of ammonia and ammonium levels in water is a commonly measured
parameter in environmental water, potable water and waste water. The determination
is so vital because, ammonia is found naturally in water, but if it is found at higher than
natural levels this is a sign of contamination. Ammonia levels higher than around 0.1
mg/L usually indicate polluted waters. Ammonia is colourless and odourless in small
amounts, so the only way to detect it is through ammonia testing. This is particularly
vital in fisheries as, although fish naturally excrete ammonia, an accumulation can harm
fish. Early detection allows for the elimination of ammonia before the concentration
reaches toxic levels. The determination of ammoniacal nitrogen can be done through
APHA 4500-NH3 B & E 20TH Edition, 1998 (Titrimetric method) which is preliminary
distillation step and ammonia-selective electrode method using known addition. The
diluted sample is buffered at pH 9.5 with a borate buffer. After that, the sample
undergoes distillation and the distillation product will be titrated with standard
sulphuric acid, 0.02N with the end point appearance of purple-blue color. From
titration, the result was 47.43 mL. Hence the ammoniac nitrogen of the sample was
successfully obtained at 131.66 mg/L. The result when compare to the National water
quality standard was high and was under category of V water class.
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2. OBJECTIVE AND INTRODUCTION
2.1.OBJECTIVE
ο‚·
To determine the ammoniacal nitrogen in the given water sample through titrimetric
method.
ο‚·
To compare the result obtained with standard water
2.2.INTRODUCTION
Ammonia is toxic to fish and humans. Ammonia is used in fertilizer and animal feed
production as well as in the manufacture of plastics, paper, rubber, etc. The levels of
ammonium /ammonia in environmental waters has been affected improper disposal
from these industries. As for concern the major contributor of ammonia concentration
comes from agricultural runoff, sewage effluent, landfill leachate and industrial
effluent. Ammonia is toxic to fish and other aquatic organisms, even in very low
concentrations. The higher the pH and the warmer the water, the more toxic the
ammonia. In addition to the actual ammonia in the water being toxic to aquatic life, it
can also cause eutrophication in a water body promoting the growth of choking aquatic
vegetation or algal blooms that disrupt the normal functioning of the ecosystem and
reduce the amount of oxygen in the water, needed for fish and other aquatic life to
survive
Ammonia is colorless and odorless in small amounts, so the only way to detect it is
through ammonia testing. Early detection allows for the elimination of ammonia before
the concentration reaches toxic levels. This is why an ammonia water test is vital for
these ecosystems.
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3. THEORY AND EXPERIMENTAL METHODS
3.1.THEORY
Ammoniacal nitrogen (NH3), is a measure for the amount of ammonia.
Ammonia is highly soluble in water. Ammonia reacts with water (H2O) and forms the
ionized form:
The values of ammoniacal nitrogen in water or waste liquids are measured
in milligram per liter. Usually the titrimetric method was in ammoniacal nitrogen analysis.
The titrimetric method is used only on samples that have been carried through preliminary
distillation.
The sample is buffered at pH 9.5 with a borate buffer to decrease hydrolysis of cyanates
and organic nitrogen compounds. At low pH, the interference (Amines) will be enhanced,
reduce the accuracy of the experiments. While at high pH it will reduce interferences make
the analysis more acceptable. The presence of NaOH solution will reduce the interferences
by mercury and silver by complexing with ammonia. It is then distilled into a solution of
boric acid when titration is to be used or into 𝐻2 𝑆𝑂4 . The ammonia in the distillate can be
determined titrimetrically with standard 𝐻2 𝑆𝑂4 and a mixed indicator.
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3.2.EXPERIMENTAL METHODS
3.2.1. Apparatus
ο‚·
Electrical heating device, adjustable
ο‚·
Distillation apparatus, consist of :
A 1 litre round bottom flask, capacity: 300-500ml (24/29), made of Pyrex glass
itted with a dropping funnel, multiple adapter, splash head, together with a suitable
vertical condenser and a delivery adapter.
3.2.2. Reagents
ο‚·
Borate buffer solution:
ο‚·
Sodium Hydroxide, 6N NaOH:
ο‚·
Absorbent solutions, plain boric acid:
ο‚·
Mixed methyl red indicator:
ο‚·
Phenolphthalein indicator
ο‚·
Ammonium Chloride standard, 1000 ppm
ο‚·
Sulphuric acid, 1N
ο‚·
Sodium Hydroxide, 1N
3.2.3. Procedure
Preparation of reagents
a) Borate buffer solution
1. 88 ml of 0.1N NaOH solution was added to 500ml 0f 0.025M sodium
tetraborate (π‘π‘Ž2 𝐡4 𝑂7 ) solution and diluted to 1 liter.
b) Sodium hydroxide, 6N NaOH
1. NaOH with mass of 240g was dissolved in 1 liter ammonia-free distilled water.
c) Absorbent solutions, plain boric acid
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1. 20g of 𝐻3 𝐡𝑂3 was dissolved in ammonia-free distilled water and diluted to 1
liter.
d) Mixed methyl red indicator
1. 0.2g methyl red was dissolved in 100ml isopropyl alcohol.
2. 0.10g methylene blue was dissolved in 50ml isopropyl alcohol.
3. These two solutions were combine
e) Ammonium Chloride standard, 1000 ppm
1. 3.819g of 𝑁𝐻4 𝐢𝑙 was dissolved in 1 liter distilled water.
Sample preparation
1. Sample was measured to 1000 ml, added to the distillation flask and was diluted in
100ml deionized water.
2. Then, 25 ml of borate buffer was added to the solution.
3. pH of the solution was adjusted to pH=9.5 with 20 ml of 24% of NaOH using 3
drops of phenolphthalein indicator.
Distillation
1. The prepared 5000ml conical receiving flask was added with 25ml of plain
absorbent solution then 2-3 drops of mixed methyl red indicator was added for
titrimetric method. The tip of delivery tube has been make sure was below the
surface of the absorbent solution. Delivery adapter then was fitted to this flask.
2. The contents in the distillation flask was boiled for 2.50 minutes until about 200ml
of distillate was collected in the receiver.
3. Excessive frothing has been avoided especially during the boiling of the mixture.
4. The distillate was immediately titrated with standard sulphuric acid, 0.02N (end
point was when the appearance of purple-blue color was appeared).
5. Control blank was carried out follows the exact procedure by replacing sample with
distilled water (in each batch of determination).
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4. RESULTS AND DISCUSSION
Ammoniacal nitrogen are important parameters that are used in water quality
measurement. The presence of ammonia nitrogen can be seen in a water sample. In
determination of ammoniacal nitrogen in the water sample we use the titrimetric
method. In this water quality analysis, I had determined the ammoniacal nitrogen in
given water sample and compare to the content limit.
From experiment, the ammoniacal nitrogen (𝑁𝐻3 ), π‘šπ‘”/𝐿 has been obtained for
sample, standard and blank. For blank solution it is 0 mg/L, while for standard it is 52.9
mg/L and for the sample it is 131.66 mg/L
Ammoniacal Nitrogen (𝑁𝐻3 ), mg/L
Blank solution
0
Standard solution
52.9
Sample
131.66
From the experiment, we found that the reading of sample that have recorded is 131.66
mg/L is more higher compared to the standard due to high concentration ammonia in
that water sample. High concentration occurs in water polluted by sewage or some
kinds of industrial wastes containing organic nitrogen or free water ammonium salts.
When the value obtain was compared with National Water, the value was considered
high and does not suitable for drinking purposes.
Our sample in consist of high level of ammonia concentration, will harm the aquatic
animal. The high concentration of ammonia in the water greater than 5 mg/L will cause
excessive growth of algae and other plants, leading to accelerated eutrophication or
'aging' of lakes, and occasional loss of dissolved oxygen. Animals and humans cannot
use inorganic forms of nitrogen, so nitrate is not a nutrient for us.
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5. CONCLUSIONS
In conclusion, using titrimetric method the ammoniacal nitrogen of the given sample has
been obtained which is recorded at 131.66 mg/L. Then, the value was considered high
when
compare
to
National
Water
Quality
Standard
for
Malaysia
because
exceeded >2.7mg/L and was categorized under V class of river water.
6. REFERENCES
ο‚·
Standard Methods: 4500-NH3 B: Ammonia: Preliminary Distillation Step.
Retrieved from https://www.nemi.gov/methods/method_summary/9887/
ο‚·
NEMI
Method
Summary
-
4500-NH3
E.
Retrieved
from
https://www.nemi.gov/methods/method_summary/7435/
ο‚·
Ammonium / Ammonia Water Test Meters & Probes From Aquaread. (2008).
Retrieved
from
https://www.aquaread.com/need-help/what-are-you-
measuring/ammonium-ammonia/
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7. APPENDICES
A. Data Tables
Blank solution
Standard
Sample
Sample volume, mL
Titration value,
mL
100 mL distilled
water
100 mL standard
ammonium
chloride,1000 ppm
100 mL sample
solution
0.41
Ammoniacal
nitrogen
(𝑁𝐻3 ), π‘šπ‘”/𝐿
0
19.32
52.9
47.43
131.66
B. Sample Calculations
Ammoniacal Nitrogen (mg/l) =
(π΄βˆ’π΅) × 280
𝐢
A = volume of standard 𝐻2 𝑆𝑂4, 0.02N used in titrating sample, ml.
B = volume of standard 𝐻2 𝑆𝑂4, 0.02N used in titrating blank, ml.
C = volume of sample used (ml)
οƒ˜ Blank
=
(0.41βˆ’0.41)×280
100
= 0 π‘šπ‘”/𝐿
οƒ˜ Standard
=
(19.32βˆ’0.41)×280
100
= 52.9 π‘šπ‘”/𝐿
οƒ˜ Sample
=
(47.43βˆ’0.41)×280
100
= 131.66 π‘šπ‘”/𝐿
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C. National Water Quality Standard for Malaysia
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