INDEX
Introduction
1
Materials
2
Methods
a) Water sample testing
i.
Determination of Chemical oxygen demand
ii.
Determination of Biological oxygen demand
iii.
Determination of Total Suspended solids
iv.
Determination of oil and grease
v.
Determination of alkalinity
vi.
Determination of total hardness
vii.
Determination of Sodium
viii. Determination of Chloride
ix.
Determination of nitrate
b) Air quality testing
i.
Determination of Suspended particulate matter
ii.
Determination of SO2 in stack sample
3
Results
4
References
1
INTRODUCTION
2
WATER QUALITY TESTING:
Water quality refers to the chemical, physical, biological, and radiological
characteristics of water. It is a measure of the condition of water relative to
the requirements of one or more biotic species and or to any human need
or purpose.
It is most frequently used by reference to a set of standards against
which compliance can be assessed. The most common standards used to
assess water quality relate to health of ecosystems, safety of human
contact and drinking water. The parameters for water quality are
determined by the intended use. Work in the area of water quality tends to
be focused on water that is treated for human consumption, industrial use,
or in the environment. Water quality depends on the local geology and
ecosystem, as well as human uses such as sewage dispersion, industrial
pollution,
use
of
water
bodies
as
a heat
sink
and
overuse.
In urbanized areas around the world, water purification technology is used
in municipal water systems to remove contaminants from the source water
(surface water or groundwater) before it is distributed to homes,
businesses, schools and other recipients. Water drawn directly from a
stream, lake, or aquifer and that has no treatment will be of uncertain
quality.
Dissolved minerals, salts metals and other suspended particles may affect
suitability of water for a range of industrial and domestic purposes. The
most familiar of these is probably the presence of ions of calcium and
magnesium which interfere with the cleaning action of soap, and can form
hard sulfate and soft carbonate deposits in water heaters or boilers. Hard
water may be softened to remove these ions. The softening process often
substitutes sodium cations. Hard water may be preferable to soft water for
human consumption, since health problems have been associated with
3
excess sodium and with calcium and magnesium deficiencies. Softening
decreases nutrition and may increase cleaning effectiveness. Hence all
these factors are tested.
AIR QUALITY MONITORING:
Air quality monitoring is the process of testing and analyzing the air quality
of office, industrial area, transport facility etc,. The reason why testing air
quality is so important is that it directly affects employees’ performance,
customers’ well-being and in fact anyone who steps inside the building.
Poor indoor air quality can adversely affect our health and the
environment with a significant cost to business and the economy. Air
pollutants can cause health problems such as sore eyes, burning in the
nose and throat, headaches, or fatigue. Other pollutants cause or worsen
allergies, respiratory illnesses (such as asthma), heart disease, cancer,
and other serious long-term conditions. Common pollutants and sources
of pollutants in buildings include Moulds and bacteria resulting from
dampness, Asbestos and dust, Diesel particulates, Vehicle exhaust,
Cleaning products, Gas and fumes, Pesticides, Solvents and other
chemicals etc.
The objective of this study is to assess the quality parameters of water
from different sources like tap water, pond water, industrial effluent,
treated water etc.
4
MATERIALS
AND
METHODS
5
MATERIALS
The inorganic salts and organic solvents required for the experiments
were procured from reputed chemical suppliers like SRL CHEMICALS,
Merck, RANCHEM, CDH etc.,
Instruments like Chemical weighing balance (RADWAG), Hot air oven
(Rotek), Flame photometer (Systronics), UV-Visible spectrophotometer
(Systronics), Water bath (Rotek),, COD digester (SPECTRALAB), BOD
incubator (C,M. Equipment and Instruments), were used for the present
work.
Different Water Samples like waste water samples, tap water samples,
potable water samples and spiked water samples were used for testing
different parameters.
Determination of Chemical Oxygen Demand
MATERIALS REQUIRED
Reflux apparatus consisting of flat bottom condenser, refluxed with 150250 ml of water, Standard K2Cr2O7 (0.25N), 120 mg of sulphamic acid( to
eliminate Nitrogen interference),
Sulphuric acid - Silver sulphate reagent (5.5g AgSO4 in 1kg of
conc.H2SO4), Standard Ferrous ammonium sulphate (0.25M) -2 ml
H2SO4+98 ml H2O,
Ferroin indicator – 1.48g of Phenanthroline monohydrate and 695 mg of
ferrous sulphate made up to 100ml, Mercuric sulphate, Potassium
hydrogen phthalate – 425 mg in 100 ml of distilled water.
STANDARDIZATION:
6
25 ml of Standard K2Cr2O7 (0.25N) was diluted to 100ml using distilled
water. 30ml of conc.H2SO4 was added. 3 drops of Ferroin indicator was
added and titrated against Standard Ferrous ammonium sulphate (0.25M)
till colour changed to wine red.
PROCEDURE:
Mercuric sulphate (0.5g) crystals were placed in reflux tube. To this tube,
10ml of sample or blank was added. Contents were mixed well and 5 ml
of Standard K2Cr2O7 solution followed by 15 ml of sulphuric acid silver
sulphate reagent was slowly added. Mixed well. Tubes were connected to
the condenser and refluxed for 2 hours at 150°C.
Condensers were then cooled and washed with known amount of water.
Flasks were removed and about 40 ml of distilled water was added and
titrated against Standard ferrous ammonium sulphate using ferroin as
indicator. Titration was stopped when colour changed to wine red.
Blank was also refluxed under identical condition.
Chemical Oxygen Demand (COD) was calculated using the equation
(A-B) × N×8×1000
COD, (mg/L) = -----------------------Volume of sample taken
Where A is Volume of Ferrous Ammonium Sulphate (FAS) required for
blank
B is Volume of FAS required for sample
N is Normality of FAS obtained after standardization
7
Determination of Biological Oxygen Demand in Water and
Waste Water Sample
APPARATUS:
300ml (BOD) bottles, Pipettes, measuring cylinders and conical flasks,
Incubators with specified temperature.
REAGENTS:
Reagents for dilution water:
Phosphate buffer solution:
8.5 g KH2PO4, 21.75 g K2HPO4, and 33.4 g Na2HPO4 7H2O and 1.7 g
NH4Cl was dissolved in about 500ml of Distilled water and diluted to 1 Lt.
The pH was maintained to be 7.2 without any further adjustment.
Magnesium sulfate solution:
22.5 g MgSO4.7H2O was dissolved in distilled water and diluted to1 Lt.
Calcium Chloride solution:
27.5g CaCl2 was dissolved in distilled water and diluted to 1 Lt.
Ferric Chloride solution:
0.25g FeCl3.6H2O was dissolved in distilled water and diluted to 1 Lt.
PROCEDURE:
Preparation of dilution water:
Required volume of water was aerated with supply of clean compressed
air in a suitable container and 1ml each of phosphate buffer, MgSO 4
solution, CaCl2 solution and FeCl3 solution was added per one liter
8
aerated water and was mixed thoroughly. Dilution water temperature to 27
°C ± 3°C was maintained.
Requisite quantity of sample was taken under test in one liter volumetric
flask. Diluted to the mark with the dilution water by siphoning from the
container. Mixed well. Three BOD bottles were rinsed with the diluted
sample and filled up these bottles with the diluted sample. The bottles
were stoppered immediately after removing the air bubbles.
To this 2 ml of manganous sulphate, alkali iodide azide, concentrated
H2SO4 reagents were added in the same order one after the other.
Preparation of Reagents for Determination of Dissolved Oxygen:
Manganous sulfate solution:
364g of MnSO4. H2O was dissolved in distilled water, filtered and diluted
to 1 Lt.
Alkali - iodide – azide solution:
500 g of NaOH and 135 g of NaI was dissolved in distilled water and
diluted to 1Lt.10 g of Sodium azide (NaN3) was added and dissolved in 40
ml distilled water.
Concentrated H2SO4
Standard sodium thiosulfate (0.025N):
6.205 g Na2S2O3. 5H2O was dissolved in distilled water. 0.4 g of NaOH
pellet was added and diluted to 1000ml and was standardized against
standard K2Cr207.
Starch as indicator:
9
2g of laboratory grade starch powder and 0.2g of salicylic acid was added
as a preservative in 100ml hot distilled water.
STANDARDIZATION:
5 ml of std. K2Cr207, 50ml of distilled water, 10ml H2SO4 and 1g of KI was
added and left for 6 minutes in dark and was titrated against Na2S2O3
solution using starch as indicator.
Determination of Initial Dissolved Oxygen (DO):
Initial Dissolved Oxygen (DO) was determined for one bottle and other
two bottles were kept for incubation at 27°C ± 1°C for 72 h (3 days). 3
blanks were prepared by siphoning out dilution water directly into the
bottles. Initial DO was determined for first bottles and
remaining two
bottles were incubated at 27°C ± 1°C for 72 h (3 days). During incubation,
to ensure proper sealing, water was added to the flared mouth of the
bottle from time to time.
Determination of Final DO:
After 72 h (3 days) incubation at 27°C ± 1°C, determine final DO in
incubated bottles.
TITRATION
204ml of sample or blank was taken in conical flask and was titrated
against standard sodium thiosulphate using starch as indicator.This was
done to determine initial and final DO of sample and blank, before and
after incubation.
Biological Oxygen Demand was calculated from the equation
10
(D1-D2) - (B1-B2)
BOD, mg/L = ------------------------ x 1000
Volume of sample taken
Where,
D1
=
Initial DO of sample in mg/L
D2
=
DO of sample after incubation in mg/L
B1
=
DO of blank before incubation in mg/L
B2
=
DO of blank after incubation in mg/L
Determination Of Total Suspended Solids In Water Sample
MATERIALS REQUIRED:
Glass fiber filter paper, filtration apparatus, vacuum pump, filtration flask,
Hot air oven (103-105°C), analytical balance, Dessicator.
PROCEDURE:
Glass fiber filter paper was conditioned in an oven at 103-105°C and
cooled in dessicator. Filter paper was weighed before use and initial
weight was recorded. Filtration apparatus was washed in distilled water.
Filter paper was placed on filter holder. Known amount of sample was
mixed well and transferred to filtration unit and vacuum pump was
switched on. Complete filtration was confirmed and the residue was
washed on paper. The filter paper was removed from filtration unit and
placed for drying in hot air oven at 103-105°C for 1 hr. It was then cooled
and was placed in dessicator. Filter paper was weighed and final weight
was noted.
Total suspended solids (mg/L) was calculated using the equation
11
Total suspended solids =
( B-A) ×1000× 1000
-----------------------Volume of sample taken
Where A = Initial weight of filter paper
B= Final weight of filter paper
Determination of Oil and Grease in Water Sample
MATERIALS REQUIRED:
Separating funnel with stop cork, filter paper, evaporation dish, HCl (1:1),
Petroleum ether, sodium sulphate crystals
PROCEDURE:
Water sample (250ml) was taken in separating funnel.To this separating
funnel, 30ml of petroleum ether and then 1ml of 1:1 HCl solution was
added. The separating funnel was shaken rigorously for 2 minutes and
was allowed to stand. After separation of layers, lower aqueous layer was
drained out. The solvent extract was transported to pre-weighed
evaporating dish, through a funnel containing about 10 gram of anhydrous
sodium sulphate in a filter paper. Evaporating dish was kept in water bath
at 80°C till solvents evaporated. Dish was cooled and kept in dessicator
for around 30 minutes. Final weight of evaporation dish was recorded.
Oil and grease weight was calculated using the equation,
Oil or grease in mg/L
(B-A) × 1000×1000
= -----------------------Volume of sample taken
Where A= Initial weight of evaporating dish
12
B= Final weight of evaporating dish
Determination of Alkalinity in Water Sample
REAGENTS:
Sodium Carbonate solution(0.02N), standard stock sulphuric acid(1N),
standard sulphuric acid(0.02N), Phenolphthalein indicator, Methyl orange
indicator.
PROCEDURE:
The burette was filled with sulphuric acid reagent. Known amount of
sample was taken in conical flask and 2-3 drops of phenolphthalein
indicator was added. Since there was no pink colour, 3 drops of methyl
orange was added. It was titrated against sulphuric acid till the colour
changed to orange from yellow.
A × N×50×1000
Total alkalinity (mg/L) = -----------------------Volume of sample taken
Where A = volume of sulphuric acid consumed (titre value)
N = Normality of sulphuric acid
Determination of Total Hardness in Water Sample
MATERIALS REQUIRED:
Burette, conical flasks, weighing balance etc.
REAGENTS:
13
EDTA [0.01M]: 3.723g of Ethylene diamine tetra acetic acid(EDTA) was
weighed and was dissolved in distilled water & diluted to 1000ml.
Erichrome Black – T: 0.5g of Erichrome black dye was dissolved in 100g
of tri ethanol amine.
Standard calcium carbonate solution :
0.1g of anhydrous CaCO3 powder was weighed and added into a 100 ml
standard flask, a funnel was placed in the flask neck and 2.5ml of 1+1 HCl
was added, a little at a time until all CaCO3 had dissolved. It was then
made up to mark using distilled water.
Standardization of EDTA:
25ml of CaCO3 was taken in conical flask.75ml of distilled water was
added.10ml of 1M NaOH and pinch of Murexide indicator was added and
titrated against EDTA solution. Titre value was noted down when colour
changed from pink to blue.
PROCEDURE:
25 ml of sample was taken and 2ml of ammonia buffer was added. 1 or 2
drops of Erichrome black – T indicator was then added and titrated
against 0.01M EDTA solution. Titre value was noted down when colour
changed from pink to blue.
Titre value X factor X 1000
Total Hardness of the sample as CaCO3 = -------------------------------( mg/L)
Volume of sample taken
Where
Factor = volume of CaCO3 taken / Titre value (EDTA consumed)
14
Determination of Sodium in Water Sample
MATERIALS REQUIRED:
Glass wares, Flame photometer
REAGENTS:
Stock Sodium Chloride solution: 2.542g of NaCl crystals was dissolved in
distilled water and was made upto 1000 ml using distilled water.
Standard solution: Working standards were prepared in a range of 10, 20,
30, 40 and 50 mg/L.
PROCEDURE:
Sodium filter was selected with the help of filter selector of the burner unit
of flame photometer. The burner was ignited and the air supply was
adjusted. Pressure was maintained between 0.4 – 0.6 Kg/cm2 and gas
supply was adjusted so as to get blue cone flame in the burner.
Distilled water was fed to the atomizer, kept for 30 seconds and meter
reading was adjusted to Zero. The standard solutions were run first
adjusting the meter reading to 50 by using 50 mg/L standard solution. 20
mg/L standard solutions were fed. Distilled water was fed between
standard runs. This was done to ensure that the meter showed zero for
distilled water. The filtered water sample was then run, reading was noted
down from display unit.
15
Determination of Chloride in Water Sample
REAGENTS:
Calcium carbonate, standard silver nitrate titrant (0.0141N), standard
NaCl (0.0141N).
PROCEDURE:
Preparation of Standard Sodium Chloride 0.0141 N: 82.485mg of NaCl
(dried at 140°C ) was dissolved in distilled water and made up to 1000 ml
in volumetric flask (1ml = 500µg Cl)
Standardization of silver nitrate solution:
Silver Nitrate titrant was standardized against 10 ml of
NaCl using
potassium chromate (K2CrO4) indicator with pinkish yellow end point.
Titration:
Samples were directly titrated in the pH range 7 to 10. Sample pH was
adjusted to 7 to 10 with CaCO3 powder when the sample was acidic.3-5
drops of potassium chromate was added as indicator. It was then titrated
against standard silver nitrate solution until colour changed to pinkish
yellow
Titre value×N×35.45×1000
Concentration of chloride ion =
-------------------------Sample taken
Where N= Normality of silver nitrate
16
Determination of Nitrate in Water Sample
REAGENTS:
Stock Nitrate solution: 0.721g of potassium nitrate was dissolved in 1Lt
distilled water.
Standard nitrate solution: 100ml of stock solution was diluted to1000ml
with water.
1N hydrochloric acid was added to all standard nitrate solutions.
PROCEDURE:
Treatment of sample: 1ml of hydrochloric acid was added to 50ml clear
sample and mixed.
Spectrophotometric measurements:
Absorbance was read against distilled water and absorbance was set to
zero.
Measurement of absorbance for nitrate concentration:
Absorbance was measured at 220nm to obtain reading for nitrate and
reading at 275nm was also determined to rule out the interference of
nitrite ion and dissolved organic matter.
17
Determination of Suspended Particulate Matter in Air
SAMPLING:
The most easily available and convenient method for sampling of
particulate from air is the filtration technique.
Sampling is usually done at 1.5 m height raise the control module on the
stand.
PROCEDURE:
It was ensured that the filter was parallel to the ground. The face plate of
the sampler was removed and checked. The pan was then removed and
cleaned and the inlet and separator unit on the control module were
replaced. The inlet and separator unit were removed by depressing the
ball latches and lifting up, placing it on the ground or a table next to the
sampler. The pan was then tapped to settle the collected particulate
matter to the bottom. The pan was supported from below and the four
screws were removed. Holding the pan horizontal, particulate matter to
be saved into a weighing paper was tapped, folded and placed in a
plastic. The exposed filters were weighed on the analytical balance.
Determination of Sulphur Dioxide Emissions from Stationary
Source
Reagents:
80 % Iso-propanol, 3 % Hydrogen peroxide, Thorin Indicator (0.2g of
thorin in 100ml distilled water)
Barium Perchlorate (0.01 N): 1.95 g of Barium Perchlorate was dissolved
in 200 ml of iso – propanol and was diluted to 1Lt with distilled water.
18
APPARATUS:
Stack Sampler, Semi micro balance, Glass wares
SAMPLING:
15 ml of 80 % iso-propanol and 15 ml of 3% hydrogen peroxide was
poured into the first two Impinger. The final Impinger was left dry. The
sampler was assembled. The sample flow rate was adjusted in the range
of 2 to 5 L/min. The tip of the probe was positioned at the sampling point.
After collection the probe was removed from the stack. Impingers were
then disconnected after purging. After making up to the final volume, the
contents are poured into a polyethylene bottle. The Impinger and the
connecting tube were rinsed with distilled water and these washings were
added to the same bottle.
ANALYSIS PROCEDURE:
The contents of the storage container were transferred to a 50 ml
volumetric flask and made upto the mark using distilled water. 10 ml of
aliquot of this solution was pipetted into a 125 ml conical flask. 40 ml of
iso-propanol was then added. 2 to 4 drops of Thorin indicator was added
and titrated against0.01N of Barium perchlorate until pink end point was
reached.
19
RESULTS
20
Determination of Chemical Oxygen Demand
Chemical Oxygen Demand (COD) is used as a measure of
oxygen equivalents of organic matter that is susceptible to oxidation by
strong chemical oxidants. The water sample is refluxed in strong acid
solution with known excess of potassium dichromate. After digestion, the
remaining unreduced potassium dichromate is titrated against standard
ferrous ammonium sulphate to determine the amount of potassium
dichromate consumed and the oxidizable organic matter is calculated in
terms of oxygen equivalents. In the present study, industrial effluent was
used to study the COD level. Silver sulphate is used as catalyst to
promote oxidation. Mercuric sulphate is added to avoid chloride
interference.
(3.9-3.8)×0.235×8×1000
Chemical Oxygen demand , mg/L =
-----------------------10
=18.864 (mg/L)
Determination of Biological Oxygen Demand
In this test, standardized laboratory procedures are used to determine the
relative oxygen requirements of water and waste water. A number of
factors, such as soluble and floatable solids, oxidation of reduced ions
and sulfur compounds, may affect the accuracy and precision of BOD
measurements. In the present study, industrial effluent was used to study
the BOD level.
21
The method consists of filling with samples to overflowing, airtight bottles
of 300 ml size and incubating for 3 days at 27°C temperature. Dissolved
oxygen (DO) is measured initially and after incubation, and the BOD is
computed from the difference between initial and final DO. When the
Manganous sulfate is added to the solution containing sodium or
potassium hydroxide, manganous hydroxide is formed which is oxidized
by the dissolved oxygen of the sample to basic manganous oxihydroxide.
On addition of concentrated H2SO4 the basic manganous oxi-hydroxide
forms manganous sulfate which further reacts with Iodide liberating Iodine
equivalent to that of DO originally present in the sample. The liberated
iodine is titrated with standard solution of sodium thiosulfate using starch
indicator.
MnSO4 + 2 NaOH
Mn(OH)2+Na2SO4
2Mn(OH)2 + O2
2 MnO (OH)2
MnO(OH)2 + 2H2SO4
Mn (SO4)2 + 3H2O
Mn(SO4)2 + 2NaI
MnSO4 + Na2SO4 + I2
2Na2S2O3 + I2
Na2S4O6 + 2NaI
If biological growth is noticed in any of the above reagents during storage,
discard and prepare freshly.
Sample volume and Dilution Techniques:
On the basis of chemical oxygen demand (COD), expected BOD is
determined (normally 40 to 60 % of COD may be considered as expected
BOD depending upon the strength of waste).
22
In case of high BOD samples of 500 and above, prepare primary dilution
with distilled water and then make the final dilution. Samples of natural
surface water bodies like river, lake and marine, generally do not require
dilution due to low BOD values. For such samples the dilutions can be
kept 25 to 100% depending upon the expected BOD.
The following dilutions are suggested:
Type of wastewater
Strong trade waste
Raw or settled sewage
Biologically treated effluent
Polluted river water
% of dilution suggested
0.1 to 1.0 %
1.0 to 5.0 %
5.0 to 25.0 %
25.0 to 100.0 %
Calculations
(D1-D2) - (B1-B2)
BOD, mg/L = ------------------------ x 1000
Volume of sample taken
D1
D2
B1
B2
=
=
=
=
Where,
Initial DO of sample in mg/L
DO of sample after incubation in mg/L
DO of blank before incubation in mg/L
DO of blank after incubation in mg/L
BOD, mg/L =
(7.4-1.1) - (7-6)
------------------------ x 1000
204
= 25.98
23
Determination of Total Suspended Solids
It is gravimetric method where a well-mixed sample is filtered through a
weighed standard glass fiber filter, dried to a constant weight at 105°C.
The increase in weight of filter paper represents the suspended solids. In
the present study, well water was used to study the TSS level.
Initial weight of filter paper =A= 0.1133g
Final weight of filter paper = B = 0.1135g
( B-A) ×1000× 1000
Total suspended solids = - ----------------------Volume of sample taken
=
(0.1135-0.1133) × 106
-----------------------25
=8 mg/L
Determination of Oil And Grease
Oil and grease present in water may be unsatisfactory for various
purposes. It may reduce waste water treatment efficiency, may cause
surface films, and deposits leading to environmental degradation. In the
present study, industrial effluent was used to study the BOD level. Oil and
grease is extracted from water by intimate contact with an extracting
solvent.
Groups of substances with similar physical characteristics are determined
quantitatively on the basis of their solubility in an organic extracting
24
solvents. The weight of the residue after solvent evaporation constitutes
for oil and grease content.
Initial weight of evaporating dish = A = 50.5074g
Final weight of evaporating dish = B =50.5844g
(B-A) × 1000×1000
Oil or grease = -----------------------Volume of sample taken
(50.5844-50.5074) × 106
= -----------------------250
=308 mg/L
Determination of Alkalinity
Alkalinity of water is it’s acid neutralizing capacity. It is the sum of entire
titrable bases. Alkalinity of surface water is primarily a function of
carbonate, bicarbonate and hydroxyl content. Therefore alkalinity is taken
as an indication of the concentration of these constituents. The hydroxyl
ion present in the sample as a result of dissociation or hydrolysis of
solutes reacts with the added standard acids. This is a titrimetric method.
In the present study, well water was used for determining alkalinity.
A × N×50×1000
Total alkalinity (mg/L) = -----------------------Volume of sample taken
Where A = volume of sulphuric acid consumed (titre value)
N = Normality of sulphuric acid
25
Total alkalinity (mg/L) =
=
0.4×0.0208×50×1000
-----------------------25
16.64mg/L
Determination of Total Hardness
Hardness of water is the traditional measure of the capacity of water to
react with soap. More hard the water, more the soap required to produce
lather.
Hardness is not a specific constituent but is a variable and
complex mixture of cations and anions. It is mainly due to Calcium and
Magnesium ions, however, some other polyvalent ions such as aluminum,
iron, manganese, strontium and zinc also contribute to hardness.
In
natural water, it is defined as source of the calcium and magnesium ions
expressed as calcium carbonate. Although, hardness is caused by cat
ions, it may also be discussed in terms of carbonate (temporary) and noncarbonate (permanent) hardness. The hardness varies depending on the
source and treatment to which the water has been subjected to. In the
present study, well water was used to study the hardness level.
EDTA (Ethylene diamine tetra acetic acid) and it's sodium salt forms a
chelate complex when added to a solution of calcium and magnesium cat
ions. When Erichrome Black T (EBT) is added to an aqueous solution
containing calcium and magnesium at pH 10 + 0.1 the solution becomes
wine red because the metals form an unstable complex with dyes. When
26
all the magnesium and calcium has been complexed, the solution turns
blue as the indicator will be free from metal-indicator unstable complex
marking the end point of titration.
Strength of EDTA = (0.01×25) /27.5
= 0.009090N
Total Hardness of the sample =
as CaCO3 mg/L
Titre valueX factor X 1000
-------------------------------Volume of sample taken
Where, Titre value is equal to the volume of EDTA consumed
volume of CaCO3 taken
Factor = -------------------------------- = 25/27.5= 0.9090
Titre value
Total Hardness of the sample as CaCO3 mg/L
Titre value X factor X 1000
= -------------------------------Volume of sample taken
4.5X 0.9090X 1000
Total Hardness of the sample mg/L = ------------------------------25
= 163.62 mg/L
27
Determination of Sodium
Sodium is the sixth abundant element present in most of the natural
waters. In the present study, industrial effluent was used to study the
sodium level. Soil permeability can be harmed by high concentration of
sodium. Trace amount of sodium can be determined by direct reading
type of flame photometry. The sample is sprayed into a gas mixture flame
and excitation is carried out under carefully controlled and reproducible
conditions. The intensity of light is proportional to the concentration of
sodium in the solution.
Figure: Flame photometer used for determining Sodium
Sodium content in given sample
71.2Mg/Lt.
28
Determination of Chloride
Chloride is one of the major inorganic anion. If chloride concentration is in
high content, then it may be harmful for growing plants and metallic pipes.
In neutral or slightly alkaline solution, chromate can indicate the end point
of silver nitrate titration of chloride ion. Silver chloride is precipitated
quantitatively. In the present study, industrial effluent was used to study
the sodium level.
STANDARDIZATION OF SILVER NITRATE:
10×0.0141
= ------------------------------Titre value
Normality of SILVER NITRATE
10×0.0141
=-------------------------- =0.014259
9.9
Concentration of chloride
=
Titre value×N×35.45×1000
-------------------------Sample taken
0.9×0.014259 ×35.45×1000
=
-------------------------25
= 18.1973 mg/L
29
Determination of Nitrate
Effluent of nitrifying biological treatment plants may be formed in water.
Through the agricultural practices nitrate may get into ground water. In the
present study, industrial effluent was used to study the nitrate level.The
UV technique that measures absorbance at 220 nm is suitable for
quantifying nitrate. Because of dissolved organic matter, a second
measurement at 275 nm may be used to correct the nitrate values.
CONCENTRATION
20
40
60
80
100
BLANK
SAMPLE
WAVELENGTH
220nm
275 nm
0.046
0.048
0.052
0.058
0.061
0.0
0.066
0.019
0.016
0.014
0.016
0.012
0.0
0.009
Absorbance at 220(2×absorbance at 275)
Figure. Spectrophotometer used for determining Nitrate
30
0.008
0.016
0.024
0.026
0.037
0.0
0.048
Nitrate content in given sample
0.007 mg/L.
Determination of suspended particulate matter in air
Suspended particulate matter (SPM) are finely divided solids or liquids
that may be dispersed through the air from combustion processes,
industrial activities or natural sources.
CALCULATION:
SPM = (M2 – M1) X 106
V
Where,
SPM = mass concentration of particulates in µg/m3
M1 = initial mass of Pan or pouch, in g = 2.7234
M2 =final mass of Pan or pouch, in g =2.7717
V = air volume sample, in m3 = 1630
106 = conversion factor from grams to micro grams.
= 29.63 µg/m3.
Suspended particulate matter
Determination of Sulphur Dioxide Emissions
Flue gas emission sample is extracted from the sampling point in the
stack and the sulphur dioxide fraction is measured by Barium Thorin
titration method.
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CALCULATION:
1. SO2 Concentration:
SO2, g/Nm3 = 0.032 X (Vtit X N X Vs)
(Vfg x Va)
Vtit = Volume of barium per chlorate titrant used for
the sample, ml.= 0.2ml
Vs = Volume of absorbent used for sampling, ml
=30ml
N = Normality of barium per chlorate= 0.0147
Vfg = Volume of gas sampled,g/ Nm3= 0.05523
Va = Volume of absorbent taken for analysis, ml.
=10
= 0.0051g/Nm3.
SO2 concentration
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REFERENCES:
1. Instrument Operation manual of high volume sampler
2. Indian standard Methods for Measurement of Emissions from
Stationary Sources IS 11255 Part 2 (Reaff.2003).
3. Standard Methods for the Examination of Water and Wastewater,
(2012), 22nd Edition, American Public Health Association, American
Water Works Association and Water Environment Federation,
Washington D.C. USA.
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