KARAIKUDI INSTITUTE OF TECHNOLOGY
KIT & KIM TECHNICAL CAMPUS
Managiri(Post), Karaikudi – 630 307
DEPARTMENT OF CIVIL ENGINEERING
CE6611 – ENVIRONMENTAL ENGINEERING LAB
MANUAL
PREPARED BY
S.DINESH M.E.
(AP/CIVIL)
1
INDEX
S NO DATE NAME OF THE EXPERIMENTS
STAFF
SIGN
4
DETERMINATION OF AMMONIA NITROGEN IN WASTE
WATER
COAGULATION AND PRECIPITATION PROCESS FOR
TREATING WASTE WATER
DETERMINATION OF SUSPENDED AND DISSOLVED
SOLIDS
DETERMINATION OF VOLATILE AND FIXED SOLIDS
5
BIOCHEMICAL OXYGEN DEMAND
6
C.O.D TEST
7
NITRATE IN WASTE WATER
8
PHOSPHATE IN WASTE WATER
9
DETERMINATION OF CALCIUM, POTASSIUM AND SODIUM
BY FLAME PHOTOMETRY
10
HEAVY METALS DETERMINATION – CHROMIUM, LEAD,
ZINC.(DEMONSTRATION ONLY).
1
2
3
2
Exp.No:1
Date:
DETERMINATION OF AMMONIA NITROGEN IN WASTE WATER
Aim
To determine the amount of Ammonia Nitrogen present in the given sample.
Principle
Ammonium ion reacts with Nessler’s reagent (K2HgI4) to form a brown
colour substance, and can be determined calorimetrically. Most of the natural
waters and wastewaters have interfering substances; therefore, the steam
distillation of ammonia becomes essential.
Apparatus required
1. Measuring jar
2. Conical flask
3. Burette
4. Pipette
Reagents
1. Phosphate buffer solution
2. Boric acid
3. Methyl orange indicator
4. Sulphuric acid 0.02N
Procedure
1. Take 50ml of the sample in a conical flask.
2. Add 5ml of phosphate buffer solution and 10 ml of boric acid solution.
3. Add 3 -5 drops of methyl orange indicator.
4. Titrate against 0.02N of sulphuric acid till the end point is changes from
orange to yellow.
3
Calculation
NH3- N2 in mg/l = ml of H2SO4 x 0.28 x1000
------------------.
ml of sample
Tabulation
S.No
Vol of
water
sample
(ml)
Initial
burette
reading
(ml)
Final
Concurrent Vol of
burette burette
sulphuric
reading (ml) reading (ml) acid (ml)
Result
The amount of Ammonia Nitrogen present in the given sample is -----------mg/l.
4
Exp. No:
Date
:
COAGULATION AND PRECIPITATION PROCESS FOR TREATING
WASTE WATER
Aim:
To find out the optimum coagulant required to precipitate turbid particles
present in the water.
Principle
Metal salts hydrolyze in presence of the natural alkalinity to form metal
hydroxides. The divalent cations can reduce the zeta-potential, while the metal
hydroxides are good absorbents and hence remove the suspended particles by
enmeshing them.
Apparatus Required
 Jars mixer
 Turbid water
 Beakers
 Pipettes
 Turbidity meter
 pH meter
Reagents
Alum solution
Procedure
1. 200ml of water sample is taken in each jar. Increasing dose of alum (1%)
i.e. 1gm/100ml of distilled water added to slowly for 15min and allowed to
stand for 15min.
2. The jars are observed and the settling of sediments is noted. The quality of
added to the jar containing the clearest solution is noted.
5
3. Take the sample out of beaker and test for turbidity in each trial plot the
curve on and y axis of the graph Sheet. Take the alum dosage in ml along
x axis and turbidity along y axis.
Observations
Raw water turbidity (NTU) =
Raw water pH =
Raw water alkalinity (mg/l)
Tabulation:
Sample
details
Dosage of
coagulant
Residual
Turbidity
pH
Alkalinity
mg/l
Result:
The optimum dosage of coagulant required to remove turbidity in the given
water sample is…………………….
6
Exp. No:
Date:
DETERMINATION OF SUSPENDED AND DISSOLVED SOLIDS
Aim:
To determine the amount of dissolved solids present in the given sample.
Apparatus Required:
 Crucible
 Oven
 Desiccator
 Chemical balance.
Procedure:
 take dry crucible and take the empty weight as W1
 Take a known quantity of liquid sample in a crucible.(W2)
 The sample is filtered through watt man paper number 44. The suspended
solids will remain in the filter paper. Take the weight as W3.
 Take a known weight of filtered solution in a crucible of known weight
and dry it to a temperature of 103°C to 105°C.
 Cool the crucible in a desiccator and weight it as W4.
Application:
Dissolved solids determination gives an ideas about the formation of scales
cause of foaming in boilers, acceleration of corrosion and interference with the
color and taste of many products. The suspended solid determination is
particularly useful in the analysis of sewage and other waste water. It is used to
7
evaluate the strength of waste water and to determine the efficiency of treatment
units.
Sanitary significance:
In liquid waste dissolved oxygen is the most important factor in determining
whether the aerobic or anaerobic organisms carry out biological changes. If
sufficient D.O is available Aerobic organism oxidize the waste to stable
products. If D.O. is deficient anaerobic takes part in the conversation and reduce
the waste often to obnoxious and nuisance conditions are usually resulted.
Calculation:
Empty weight of crucible = W1 =
Weight of the sample = W2=
Weight of suspended solids = W2- W3 =
Weight of dissolved solids = W4 - W1 =
Result:
Amount of suspended solids = ------------ mg
Amount of dissolved solids = ------------- mg
8
Exp.No:
Date:
DETERMINATION OF VOLATILE AND FIXED SOLIDS
Aim:
To determine the amount of volatile and fixed Solids present in the given
sample.
Apparatus Required:
 Crucible
 Oven
 Desicator
 Chemical balance
 Muffle furnace
Procedure:
 Take dry crucible and take the empty weight as W1
 Take a known quantity of liquid sample in a crucible.(W2)
 Heat the crucible in water bath at 100°C till the entire liquid in a crucible
evaporates and dry residue remains at the bottom then place the crucible in
oven at 103°C for 1 hour.
 Take the weight of crucible with the residue after cooling it in a desiccator
for 20 minutes. Let it weight be W3.
 Take the sample crucible and keep it in a muffle furnace at a temperature
of 650°C for 30min.
 Cool the crucible in a desiccator and weight it with the fixed solids
residue. Let the weight be W4 gm.
9
Application:
Volatile solids test is normally applied to sludge. It is indispensable in the
design operation of sludge desiccator, vacuum filter and infiltration plants.
Before the development of C.OD test it is used to find the strength of industrial
and domestic waste water.it is helpful in accessing the amount biologically inert
organic matter such as lignin in the case of wood pulping waste liquor.
Environmental significance:
The water which contains of high volatile solids is not suitable for drinking
purposes. The result of high volatile solids indicated that the water may have
been pollutes by domestic waste or other organic wastes. In general , ground
water is free from volatile solids unless they have been polluted by waste
seepages. But, well water may have high volatile solids due to lack of proper
production around well to prevent seepage of used water. The surface water may
also have high volatile solids due to disposal of domestic and other wastes.
10
Calculation:
Empty weight of crucible = W1 =
Weight of the sample = W2=
Weight of volatile solids = W3- W1 =
Weight of fixed solids = W4 - W1 =
Result:
Amount of volatile solids = ------------ mg
Amount of fixed solids = ------------- mg
Amount of total solids = ------------- mg
11
Exp.No :
Date :
BIOCHEMICAL OXYGEN DEMAND
Aim:
To determine the amount of BOD present in the given sample.
Principle:
An amount of the water sample is maintained in an incubator at 20°C for
five days in a closed bottle without allowing air to enter during which time the
water sample is assumed to be sterilized, i.e. the bacterial decomposition gets
completed. Measuring the dissolved oxygen used for stabilizing the water. A
water sample with a low BOD can be straight away used for the BOD
determination. But water sample with a high BOD must be diluted and
pretreated before the determination of BOD.
Apparatus required:
 Burette with stand.
 Pipette.
 BOD Bottle.
 Conical flask.
 Measuring jar.
Procedure:
BOD determination of without dilution:
If the water sample is fairly clean would have a BOD value of less than 5 and it
can be used as such. Fill the 4 BOD bottles up to the rim. After filtration ,close
tightly foe fifteen minutes. Make sure that there are no bubbles. Use the water in
two bottles and determine the dissolved oxygen, immediately place the other 2
12
bottles in a incubator or a constant temperature water bath at 200. During
incubation the bottles should be protected from the entry of air into them. After
five days the dissolved oxygen in these two bottles are determined.
BOD determination of after dilution:
This method is used when the BOD value exceed 5.Pipette into each 2 BOD
bottles 100ml of water sample. The bottles are filled with dilution bottle
prepared. Wait for 15 minutes and stopper the bottle tightly. The DO of the
diluted water from one of the bottle is found out. The other bottle is incubated
for 5 days at 20°C and the DO of the incubated water are determined.
Tabulation:
Sl.No Volume of
sample V2 (ml)
Burette
Volume of
Reading
Burette
Initial Final
Solution V1 value(ml)
(ml)
1.
2.
13
Concordant
Calculation:
Volume of Sodium ThioSulphate,(v1) =
Volume of water sample,(v2)=
Normality of Sodium ThioSulphate, N1 =
Normality of water sample, N2=
v1 N1 = v2N2
N2=
Before incubation:
Dissolved oxygen in mg/l = V1xN1x8x1000
--------------------V2
After incubation:
Dissolved oxygen in mg/l = V1xN1x8x1000
--------------------V2
BOD (mg/l) = D.O before incubation - D.O after incubation.
Result:
The amount of BOD present in the given sample of water = ----------------
14
Exp No:
Date
C.O.D TEST
Aim
To find the chemical oxygen demand of given wastewater sample.
Principle
The organic matter present in sample gets oxidized completely by K 2Cr2O7
in the presence of H2SO4 to produce CO2 and H2O. The excess K 2Cr2O7
remaining after the reaction is titrated with Fe (NH4)2(SO4)2. The dichromate
consumed gives the O2 required to oxidation of the organic matter.
Apparatus Required
1. COD analyzer
2. COD Digester.
Reagents
1. Standard potassium dichromate 0.25N
2. Sulphuric acid with reagent (Conc.H 2SO4 + A g2SO4)
3. Mercuric sulphate
Procedure
1. Add high range or low range solution + 0.2 ml of sample solution.
2. Invert 90 degree thoroughly 5 times and fix that in stand.
3. After that we heat and digest the solution using COD digester for 2 hours.
4.
5.
Take the solution from digester and that the solution cool in 30 minutes.
Finally it placed to COD Analyzer to measure COD.
Result
The COD of the given sample is ----------------------15
Exp. No:
Date:
NITRATE IN WASTE WATER
Aim
To determine the amount of Nitrates present in given wastewater sample.
Principle
Nitrate is determined by measuring the absorbance at 220nm in sample
containing 1mL of hydrochloric acid (1N) in 100mL sample. The
concentration is calculated from graph from standard nitrate solution in range
1-11mg/L as N.
Apparatus required:
 Spectrophotometer, for use at 220nm and 275nm with matched silica cells
of 1cm or longer light path.
 Filter: One of the following is required.
 Membrane filter: 0.45µm membrane filter, and appropriate filter
assemble
 Paper: Acid-washed, ash less hard-finish filter paper sufficiently
retentive for fine precipitates.
 Nessler tubes, 50mL, short form.
Reagents and standards
 Redistilled water: use redistilled water for the preparation of all solutions
and dilutions.
 Stock nitrate solution: dissolve 721.8mg anhydrous potassium nitrate and
dilute to 1000ml with distilled water. 1mL = 100 µg N = 443µg NO3-.
 Standard nitrate solution: dilute 100mL stock nitrate solution to 1000mL
with distilled water.
1mL = 10µg NO3 N = 44.3µg NO3.
 Hydrochloric acid solution: HCl, 1N.
 Aluminum hydroxide suspension: dissolve 125g potash alum in 1000mL
distilled water. Warm to 60°C, add 55-60mL NH4OH and allow to stand
16
for 1h. Decant the supernatant and wash the precipitate a number of times
till it is free from Cl, NO2 and NO3. Finally after setting, decant off as
much clean liquid as possible, leaving only the concentrated suspension.
Calibration
Prepare nitrate calibration standards in the range 0 to 350µg N by diluting 1, 2,
4, 7…..35mL of the standard nitrate solution to 50mL. Treat the nitrate
standards in the same manner as the samples.
Procedure
Read the absorbance or transmittance against redistilled water set at zero
absorbance or 100% transmittance. Use a wavelength of 220 nm to obtain the
nitrate reading and, if necessary, a wavelength of 275nm to obtain interference
due to dissolved organic matter.
Calculation
For correction for dissolved organic matter, subtract 2 times the reading at
275nm from the reading at 220nm to obtain the absorbance due to nitrate.
Convert this absorbance value into equivalent nitrate by reading the nitrate value
from a standard calibration curve.
Nitrate N, mg/L = mg nitrate-N / mL of sample
NO3, mg/L = Nitrate N mg/L x 4.43
Precision and Bias
Because dissolved organic matter may also absorb at 220nm and nitrate does not
absorb at 275nm a second measurement can be made at 275nm to correct the
nitrate value. The extent of this empirical correction is related to the nature and
concentration of the organic matter and may vary from one water to another.
17
Filtration of the sample is intended to remove possible interference from
suspended particles. Analyse the sample in duplicate for quality assurance and
run 1-2 standards for quality control.
Interferences
Dissolved organic matter, nitrite, hexavalent chromium and surfactants are
interferences. The latter three substances may be compensated for by
independent analysis of their concentrations and preparation of individual
correction curves.
Organic matter can cause a positive but variable interference. The degree of
interference depends on the nature and concentration of the organic matter in the
sample.
Clean all glassware thoroughly and rinse to reduce the error that might result
from streaks or particles on the outside of the curves, as well as traces of
surfactants or dichromate cleaning solution that might adhere on the interior
glass surfaces.
Treat coloured samples with aluminium hydroxide suspension or dilute to
minimise colour interference.
If the sample has a high colour or is known to contain organic interferences, add
4mL Al2 (OH)3 suspension/100mL sample in an Erlenmeyer flask. Swirl to mix
and settle for 5 minutes. Filter through a 0.45µm membrane filter previously
washed with about 200mL distilled water. To 50mL clear filtered sample, add
1mL (1N), HCl and mix thoroughly.
Result
The amount of nitrate present in the given sample is ------------mg/l.
18
Exp. No:
Date:
PHOSPHATE IN WASTE WATER
Aim:
To determine of phosphates present in the water sample using
spectrophotometer.
Principle:
Phosphates in acidic condition react with ammonium molybdate to
form molybdophosphoric acid which is then reduced to molybdenum blue by
adding stannous chloride. The intensity of the blue colored complex is measured
spectrophotometrically, which is directly proportional to the concentration of
phosphate present in the sample.
Apparatus:
 Spectrophotometer
 Pipettes
 Measuring Cylinder
 Glass-Rod
 Beakers
 Dropper
Reagents:
1. Ammonium molybdate solution
In 175 ml of distilled water, add 25 g of ammonium molybdate. Now add
280 ml of conc. sulphuric acid in 400 ml of distilled water and cool it.
Make the volume up to 1 liter with distilled water.
2. Stannous chloride solution
Dissolve 2.5 g of stannous chloride in 100 ml glycerol by heating in a
water bath.
3. Standard Phosphate Solution
Dissolve 4.388 g of anhydrous potassium hydrogen phosphate in 1000 ml
distilled water. Dilute this solution to 100 times (10ml-1000ml).This
19
solution contains 10 mg P/l (1ml = 0.01 mg P) which is used as standard
phosphate solution.
Procedure:
1. Take 50 ml of filtered and clear sample.
2. Add 2 ml of ammonium molybdate solution and 5 drops of
stannous chloride
3. Measure the blue color developed at 690 nm on a
spectrophotometer using a distilled water blank with the same
chemicals.
4. Note down the readings of spectrophotometer after 5 minutes but
before 12 minutes of the addition of the last reagent.
5. Find out the concentration of the phosphate with the help of the
standard curve.
6. Use standard phosphate solution and prepare the standard curve in
the range of 0.0 to 1.0 mg/l of PO4-P at the interval of 0.1 mg/l by
treating in the same way as the sample.
20
Preparation of Standard Curve:
Standard
PO4 solution
0.1 ml
0.2 ml
0.3 ml
0.4 ml
0.5 ml
0.6 ml
0.7 ml
Distilled water
49.9 ml
49.8 ml
49.7 ml
49.6 ml
49.5 ml
49.4 ml
49.3 ml
49.2 ml
49.1 ml
49.0 ml
---------
Ammonium
Molybdate
2 ml
2ml
2ml
2ml
2ml
2ml
2ml
2ml
2ml
2ml
Stannous Chloride
5 drops
5 drops
5 drops
5 drops
5 drops
5 drops
5 drops
5 drops
5 drops
5 drops
0.8 ml
0.9 ml
1.0
ml
50 ml
CALCULATION:
Phosphates (mg/l) = mg PO4 x 1000 ml sample
RESULT:
The amount of phosphates determined from the given sample is ________mg/l.
21
Exp.No.
Date:
DETERMINATION OF CALCIUM, POTASSIUM AND SODIUM BY
FLAME PHOTOMETRY
Aim:
To estimate the amount of sodium ion present in the given water sample
using flame photometer.
Principle
Flame photometry or flame emission spectroscopy is based on the emission of
seven radiations in visible region by a metal atom. This method is used in water
analysis for determining the concentration of alkali and alkaline earth metals
such as sodium, potassium, lithium etc. A diagram showing the basic elements
of flame photometer is given below:
A liquid sample to be analyzed is sprayed under controlled conditions into a
flame where the water evaporates, leaving the salts behind as minute particles.
The salts decompose into constituent atoms and become vaporized when they
are subjected to a flame at about 1700°C. Vapors containing metal atoms are
excited by thermal energy of the flame and this causes electrons of the metal
atoms to be raised to higher energy levels. When the electrons fall back to their
original positions or to a lower level, they give off discrete amount of radiant
energy. The emitted radiation is passed through the lens and then the filter
(optical fiber) which separates the various wavelengths and permits only the
radiation of characteristics under study. A photocell and some type of amplifier
are then used to measure the intensity of the isolated radiation.
The emission spectrum for each metal is different and its intensity depends upon
the concentration of atoms in the flame. Sodium produces a characteristic
Yellow emission at 589nm, lithium a red emission at 671nm, potassium a red
emission at 766 nm and calcium a blue emission at 423 nm.
22
Procedure
1. Switch on the flame photometer. Regulate the flow of gas and air supply.
Send the distilled water first and start ignition.
2. After the instrument is warmed up for about 10 minutes, adjust for zero
reading display in the instrument. After this no further adjustment is
required.
3. Now the sodium chloride solution of various concentrations namely 2ppm,
4ppm,
6ppm and 8ppm are introduced into the mixing chamber one by one and
note the readings for each
case.
4.
Draw the calibration graph with intensity of emitted light Vs
concentration in the ppm of sodium ions.
5. Then introduce the unknown NaCl solution and find the intensity value.
From which the concentration
of the unknown sample can be determined.
6. The same procedure can be applied for the estimation of potassium ions
in water sample by flame photometry.
23
Observation
Sl.NO
Concentration of NaCl (ppm)
Intensity of emitted light
(readings)
Sl.NO
Concentration of NaCl (ppm)
Intensity of emitted light
(readings)
24
S.NO
Concentration of KCl (ppm)
Intensity of emitted light
(readings)
RESULT
Amount of Sodium ions present in the given water sample = --------- ppm
Amount of Potassium ions present in the given water sample = --------- ppm
Amount of Calcium ions present in the given water sample = --------- ppm
25
Exp. No:
Date :
HEAVY METALS DETERMINATION – CHROMIUM, LEAD, ZINC.
(DEMONSTRATION ONLY).
Aim:
To determine the heavy metals (Chromium, Lead, Zinc) from waste water.
Apparatus required:
Atomic Absorption Spectroscopy.
Theory:
Chromium (Cr):
The permissible limit of Chromium for plants is 1.30mg/kg recommended
by WHO. In plant xanthium strumarium concentration of chromium was below
the permissible limit, in Tamarix aphyda concentration of chromium was above
the permissible limit, in the root of Dodonea viscosa concentration of chromium
was above the permissible limit while in its leaves and stem concentration was
below the permissible limit similarly in the leaves of Acacia modesta
concentration was found above the permissible limit while in its stem and root
concentration is below the permissible limit. The maximum permissible limit for
Cr in water is 0.1 mg/l. The values of Cr in all water samples ranged between
1.313 to 2.886mg/ In all the collected water samples concentration of chromium
was recorded above the permissible limit set by WHO. Concentration of
chromium in soil samples ranged between 4.123 to 6.744mg/kg. In all the
26
collected soil samples concentration of chromium was recorded above the
permissible limit set by WHO.
Lead (Pb):
The permissible limit in plants recommended by WHO is 2mg/kg. In the
leaves of Xanthium strumarium concentration of lead was recorded below the
permissible limit while in its root no lead was recorded, in the root of Acacia
modesta concentration of lead was above the permissible limit while in its stem
and leaves no lead was recorded, in the root, stem and leaves of Dodonae
viscosa no concentration of lead was recorded, in the leaves of Tamarix aphyda
concentration of lead was recorded below the permissible limit while in its root
and stem no concentration of lead was recorded. According to WHO standards
permissible limit of lead in water is 0.05mg/l and in all the collected water
samples concentration of lead was above the permissible limit. Concentration of
lead in all the collected water samples ranged between 0.167 to 0.723mg/l.
Concentration of lead in soil samples was recorded to be ranged between 0.061
to 0.461mg/kg. In almost all the collected soil samples concentration of lead was
recorded above the permissible limit set by WHO. Lead as a soil contaminant is
a widespread issue; It accumulates with age in bones aorta, and kidney, liver and
spleen. It can enter the human body through uptake of food (65%), water (20%)
and air (15%).
Zinc (Zn):
Zinc is one of the important trace elements that play a vital role in the
physiological and metabolic process of many organisms. Nevertheless, higher
concentrations of zinc can be toxic to the organism. It plays an important role in
27
protein synthesis and is a metal which shows fairly low concentration in surface
water due to its restricted mobility from the place of rock weathering or from the
natural sources. Concentration of zinc in water samples ranged between 0.211 to
0.256mg/. The permissible limit of zinc in water according to WHO standards is
5mg/l. Collected water samples concentration of zinc was recorded below the
permissible limit. WHO’s recommended limit of zinc in plants is 50 mg/kg. In
most of the collected plants no concentration of zinc was recorded while in
some it was recorded below the permissible limit. Concentration of zinc in soil
samples ranged between 0.033 to 0.349mg/kg. In all the soil samples
concentration of zinc was recorded below the permissible limit set by WHO.
Result:
Determination of heavy metals (Chromium, Lead, Zinc) from waste water
has been conducted using Atomic Absorption Spectroscopy.
28