CE 6611-ENVIRONMENTAL
ENGINEERING LABORATORY
MANUAL
PREPARED
By
R.MANIKANDAN
LECTURER
DEPARTMENT OF CIVILENGINEERING
SEMBODAI RUKMANIVARATHARAJAN ENGINEERING COLLEGE
SEMBODAI-614 820.
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
CE6611 – ENVIRONMENTAL ENGINEERING LABORATORY
OBJECTIVES:
To understand the sampling and preservation methods and significance of
characterization of wastewater.
LIST OF EXPERIMENTS:
1. Determination of Ammonia Nitrogen in wastewater.
2. Coagulation and Precipitation process for treating waste water
3. Determination of suspended, volatile, fixed and settleable solids in wastewater.
4. B.O.D. test
5. C.O.D. test
6. Nitrate in wastewater.
7. Phosphate in wastewater.
8. Determination of Calcium, Potassium and Sodium.
9. Heavy metals determination - Chromium, Lead and Zinc.
(Demonstration only)
Total =45 periods
REFERENCES
1. Standard methods for the examination of water and wastewater, APHA,
20th Edition, Washington, 1998
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
LIST OF EXPERIMENTS
Sl.
No.
Description of Equipment
1
Oxygen analyzer
2
Spectrophotometer
3
Ion – selective electrode
4
Sodium Potassium Analyzer – Flame Photometer
5
Gas Chromatography
6
Atomic absorption spectroscopy (Ni, Zn, Pb)
7
Nephlo - turbidity meter
8
BOD Analyser
9
COD Analyser
10
Jar Test Apparatus
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
Quantity
SL.NO
DATE
EXPERIMENTS
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
MARK
SIGN
DETERMINATION OF AMMONIA NITROGEN
Exp No: 1
Date
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 colorimentically. 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.
Calculation
NH3- N2 mg/l = ml of H2SO4 x 0.28 x1000
------------------Ml of sample
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
Tabulation
S.No
Initial
Vol of water burette
sample
Final
burette
reading (ml) reading (ml)
(ml)
Concurrent
burette
reading
(ml)
Vol
of
sulphuri
c
acid
(ml)
Result
The amount of Ammonia Nitrogen present in the given sample is -------- mg/l.
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
DETERMINATION OF OPTIMUM COAGULANT DOSAGE
Exp No:2
Date
Aim
To find out the optimum coagulant required to precipitate turbid particles
present in the water.
Principle
Metal salts hydrolyse 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
1. Jars mixer
2. Turbid water
3. Beakers
4. Pipettes
5. Turbidity meter
6. 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 are noted. The quality
of alum added to the jar containing the clearest solution is noted.
3. Take the sample out of beaker and test for turbidity in each trial plot the
curve on x and y axis of the graph sheet. Take the alum dosage in ml
along x axis and turbidity along y axis.
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
Observations
Raw water turbidity (NTU) =
Raw water pH =
Raw water alkalinity (mg/l) =
Sample details Dosage
coagulant
of Residual
turbidity
pH
Alkalinity mg/l
Result
The optimum dosage of coagulant required to remove turbidity in the given
water sample is…………………….
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
DETERMINATION OF SUSPENDED, VOLATILE AND FIXED SOLIDS
Exp No: 3
Date
Aim
To determine the amount of total solids, suspended solids and dissolved
solids in given sample.
Apparatus Required
1. Muffle furnace
2. Hot plate or water bath oven
3. Evaporating dish
Principle
Residual after the evaporation and subsequent drying in oven at specific
temperature (103o to 105o C) of a known volume of sample is called as total
solids.
The suspended solids can be found by filtering the water sample and
weighing the residue left on the filter paper.
Procedure
1. Take an evaporating disc of at least 100ml capacity liquid at 550 to 50 o in
a muffle furnace for about an hour cool in a desicator and weigh it as W1.
2. Evaporate 10 ml of unfiltered sample few more in the case the solids are
less than 250mg/lt in evaporating dish on a water bath over list plate
lowing temperature are not more than 98oC.
3. Cool in a desicator and weigh the residue left in a dish.
4. Weigh the filter paper without any moisture (W5)
5. Dry the paper in the oven then weigh the residue left in paper (W4).
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
CALCULATIONS
Total solids (mg/l) = (W2-W1) x 1000
----------------------V
Suspended Solids (mg/l) = (W4 – W3) x 1000
----------------------V
Dissolved Solids = Total solids – Suspended solids
Result
Total Solids = ---------------- mg/l
Suspended solids = ------------
mg/l
Dissolved solids = --------------- mg/l
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
B.O.D TEST
Exp No: 4
Date
Aim
To determine the BOD in the given wastewater sample.
Apparatus Required
BOD incubator
BOD bottle (300ml)
Principle
If sufficient oxygen is available in wastewater, the useful aerobic bacteria
will flourish and cause the aerobic biological decomposition of wastewater
which will continue until oxidation is completed.
The amount of oxygen consumed in this process is the BOD. Polluted waters
will continue to absorb oxygen for many months, and it is not practically
feasible to determine this ultimate oxygen demand.
Reagents
1. Distilled water
2. Phosphate buffer solution
3. Magnesium sulphate solution
4. Calcium chloride solution
5. Ferric chloride solution
6. Sodium thiosulphate solution
Procedure
1. Mix a known volume (4ml) of a sample of wastewater with a known
volume of aerated pure water to make 300ml diluted sample and then
calculate the D.O.of this diluted sample.
2. The diluted sample is then incubated for 5 days at 20o C .
3. The D.O.of the diluted sample ,after this period of incubation, is again
calculated.
4. The difference between the initial D.O. value and the final D.O. value
will indicate the oxygen consumed by the sewage in 5 days .
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
CALCULATION
BOD5=D.O.consumed by the diluted sample x (volume of diluted sample)
---------------------------------Volume of undiluted sewage
= dilution factor
Observations
S.No
Final
Vol
of Dilution Initial
DO
sample
(ml)
ratio
DO of of
sampl
e
sample
mg/l
mg/l
Result
BOD5 of given sample at 20oC in mg/l
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
Initia
l
Final
DO
5
days
DO of of blank BOD at
20o
Blan
k
mg/l
C
mg/
mg/l
l
C.O.D TEST
Exp No: 5
Date
Aim
To find the chemical oxygen demand of given wastewater sample.
Principle
The organic matter present in sample gets oxidized completely by
K2Cr2O7 in the presence of H2SO4 to produce CO2 and H2O. The excess
K2Cr2O7 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. Reflux apparatus
2. Hot plate/heating mantle
3. Burette
Reagents
1. Standard potassium dichromate 0.25N
2. Sulphuric acid with reagent (Conc.H2SO4 + Ag2SO4)
3. Standard ferrous ammonium sulphate 0.1N
4. Ferroin indicator
5. Mercuric sulphate
Procedure
1. Place 0.4gm of HgSO4 in the reflux flask.
2. Add 20ml of sample (or an aliquot diluted to 20ml)
3. 10ml of more concentrated dichromate solution are placed into flask
together with glass beeds.
4. Add slowly 30ml of H2SO4 containing Ag2SO4 and mix thoroughly.
5. Connect the flask to condenser. Mix the contents thoroughly before
heating.
6. Improper mixing results in bumping and the sample may be blown out.
7. Reflux for a minimum period of 2 hours. Cool and wash down the
condenser with distilled water.
8. Dilute the sample to make up 150ml and cool.
9. Titrate excess K2Cr2O7 with 0.1N Fe(NH4)2SO4 using ferroin indicator.
10.Sharp colour change from blue green to wine red indicates the end point.
11.Reflux the blank in the same manner using distilled water instead of
sample.
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
Calculations
Quantity of Fe(NH4)2SO4 added for blank = A ml
Quantity of Fe(NH4)2SO4 added for the sample = B ml
COD = (A - B) x normality of Fe(NH4)2SO4 x 8 x 1000
--------------------------------------------------------------Quantity of sample (ml)
Observations
S.NO
Volof
Burette Reading
(ml)
sample
Initial
(ml)
INDICATO
Vol
of COD of the R
Fe(NH4)2S
O4
sample mg/l
Final
( ml)
1.
2.
Result
The COD of the given sample is -----------------CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
Nitrate in wastewater
Exp No: 6
Date
Aim
To find the Nitrate nitrogen may be present in small amounts in fresh domestic
wastewater
Principle
In this experiment, nitrate will be reduced to nitrite with zinc. The nitrite
reactswith sulfanilic acid and N-1-naphthylethylenediamine to produce a red
compound.The intensity of the red color is analyzed spectrophotometrically. The
amount of zincand the contact period are important.
Special Apparatus
a. Spectronic 20 - spectrophotometer set at 520 nm.
b. Filter paper and vacuum filtration apparatus.
Reagents
a. Stock potassium nitrate solution:
0.816 g of anhydrous KNO3 is dissolved inpurified water and diluted to 1 liter to
produce a 500 mg/L nitrate solution. 100 mL ofthis solution is diluted to 1 liter to
produce the stock 50 mg/L nitrate solution whichwill be used in this experiment.
b. Hydrochloric acid diluted 1:4 1 part con. HCl and 4 partswater.
c. Sulfanilic acid: Dissolve 0.60 g of sulfanilic acid in 70 mL hot purified water,
cool,dilute to 100 mL with purified water, and mixthoroughly.
d. Zinc: Add 1.000 g finely powdered zinc to 200 g sodium chloride, NaCl, in a
bottle and mix thoroughly by shaking for several minutes.
f. N-1-naphthylethylenediamine dihydrochloride reagent:
Dissolve 0.60 g N-1-naphthylethylenediamine dihydrochloride in purified water
towhich 1.0 mL con. HCl has been added. Dilute to 100 mL and mix. Store in
refrigerator. (Stable for about aweek.)
g. Sodium acetate solution: Prepare 100 mL of 2 M NaC2H3O2.
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
Procedure:
a. Preparation of standards:
Blank: Measure 50 mL of purified water and transfer to a 250-mL erlenmeyer
flask.
2.5 mg/L standard: Add 2.5 mL of stock 50 mg/L nitratesolution to a 100-mL
graduated cylinder. Add purified water and dilute to a volume of 50 mL. Transfer
to a250-mL erlenmeyer flask.
5.0 mg/L standard: Repeat the directions for the 2.5 mg/L standard using 5.0 mL
of50 mg/L nitrate solution.
10.0 mg/L standard: Repeat the directions for the 2.5 mg/L standard using 10.0
mLof 50 mg/L nitrate solution.
15.0 mg/L standard: Repeat the directions for the 2.5 mg/L standard using 15.0
mLof 50 mg/L nitrate solution.
b. Experimental: Use the following procedure for treating standards as well as
river, lake, well, or sewage water sampl
Note: Treated sewage effluent may require a 5-fold or a 10-fold dilution. A
10-fold dilution can be performed by pipetting 5.0 mL of the treated wastewater
(sewage) sample into a 100-mL graduated cylinder and adding enough water to
bring
the volume up to 50 mL. This 50 mL sample can then be taken through the
experimental and color development procedure. A 10-fold dilution results in a
dilution factor of 10. Remember to multiply the concentration obtained for the
diluted sample by a factor of 5 or 10.
To a 50.0-mL water sample in a 250-mL erlenmeyer flask, add 1.0 mL of dilute
HCl (1:4 dilution) and 1.0 mL sulfanilic acid reagent and mix thoroughly. In a dry
10-mL graduated cylinder, measure one mL of the Zn/NaCl granular mixture and
addit to the erlenmeyer flask.
Swirl the flask for seven minutes. Filter with a vacuum flask after the seven
minute swirling period. Rinse the erlenmeyer flask well with purified water and
pourthe filtered water sample back into the flask.
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
Color Development: Add 1.0 mL N-1- naphthylethylenediamine dihydrochloride
reagent to the filtered sample and mix. Add 1.0 mL of 2 M sodium acetate
solutionand mix. Allow 5 minutes (or more) for color development.
Spectrophotometric Measurement: Measure the color intensity with a
spectrophotometer at a wavelength of 550 nm. Purified water may be used for a
blank unless the water sample is cloudy. In that case, use a sample of cloudywater
as a blank. Record the absorbance of the colored sample.
Waste Disposal
All solutions may be rinsed down the drain with water.
Calculations
From the concentration and the absorbance of the four standards, make a plot
of absorbance as a function of concentration. Use the plot and the absorbance of
each unknown solution to determine the concentration in mg/L nitrate ion (mg
NO3-/L ) in that sample. Also, express the concentration in terms of mg/L of
nitratenitrogen (mg N/L) in the sample.
Result
The Nitrate nitrogen may be present in small amounts in fresh domestic
wastewater…………
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
Determination of Calcium, Potassium and Sodium
Exp No: 8
Date
Aim:
To determine the calcium, potassium and sodium of the given water sample.
Reagents:
oral rehydration sachet
NaCl standards: 10, 20, 40, and 80 mM
Technical note: In order to measure the change in potential difference across the
ion-selective membrane as the ionic concentration changes, it is necessary to
include in the circuit a reference electrode which acts as a half-cell from which
to measure the relative deviations
Procedure:
NOTE: the bottom surfaces of the sodium ISE and reference electrode are
very fragile. Do not let them drop on to the bottom of a beaker or bottle.
(a) Ensure that the multimeter (yellow box) and electrode amplifier (grey box) are
connected properly with the black cable in the lowest socket (COM) and the
red cable in the middle socket (V mA) and that the silver BNC connector
from the electrode head is plugged into the back of the amplifier.
(b) With the electrodes immersed to a depth of about 3-4 cm in NaCl storage
solution, switch on the multimeter to the 2000 mV position (4 clicks
counterclockwise) and the amplifier to position I (down). Wait until the
reading has stabilised (up to 5 min.) then remove the electrodes from the
storage solution, wipe the bodies (but NOT the bottoms) with a tissue,
transfer to a beaker of distilled water and rinse with swirling for about 30 sec.
(c) Remove the electrodes from the water, wipe as before, then transfer to the
10 mM NaCl standard. Swirl the solution for 15 sec to help the ISE
membrane to equilibrate with the solution, then leave undisturbed for a
further minute. Note the multimeter reading (this is millivolts, mV)
(the meter may fluctuate if you wave your hand over it so ensure that the
environment is undisturbed when taking the reading).
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
(d) Remove, wipe and transfer the electrodes to the 20 mM standard and
measure as before, waiting one minute before taking the reading.
(e) Repeat the procedure for the 40 mM and 80 mM standards.
[Na+] (mM)
Log [Na+]
10
Meter reading
(mV)
10
20
40
80
5. Finally, take a reading in the same way from the undiluted
redissolved sachet from Experiment A.
6. Transfer the electrodes back to distilled water and, if nobody else is going to
use the system, switch off the multimeter and amplifier (position O).
7. Plot mV (y-axis) against log10 [Na+] (x-axis) and from this graph determine the
apparent [Na+] in the redissolved sachet solution.
Na Na+] in
Log [Na+] from
redissolved sachet
10
(mM)
undiluted sachet solution
graph
Meter reading for
Results:
a From the information provided on the sachet packaging, calculate the expected
concentrations of Na+ and K+ ions in the solution you made.
[Na+] (mM) [K+] (mM)
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
(c) How do your own values for Na+ and K+ determined by flame
photometry and for Na+ determined with the ISE compare to the
expected values?
1. The class data for sodium determination only by both methods will be
collected and tabulated on the blackboard in the class. Collect these data in the
table below before you leave (12 sets maximum). Using a calculator, calculate the
mean and standard deviation (S.D.) for the two data sets and compare these for
accuracy and precision. What do you conclude
SL.NO
1
2
3
5
6
7
8
9
10
11
12
[Na+](flame)
[Na+] (ISE)
Sodium concentration (mean ± S.D, n =) by flame photometry = ………
(mM)
Sodium concentration (mean ± S.D, n =) by ISE= ……………… (mM)
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
Phosphate in wastewater
Exp No: 8
Date
Aim:
To determine the amount of phosphate (po4)present in waste water.
REAGENTS:
Stock Solution:
This solution is only needed to make standard solution.
Dissolve 219.5 mg of anhydrous KH2PO4 and dilute to 1,000 ml. This solution
will be 50 ug P/ ml.
Standard Solution:
Dilute 25 ml of stock solution to 500 ml. This will be 2.5 ug P/ml.
The working standard is 2.5 ug/ml (2500 ppb) of phosphorus in phosphate (PO4P). Use it to make a series of standards.
Standard Solutions
Volume (ul) used of the
working standard,
diluted to 25 ml.
Standard Conc.
( ppb PO4-P )
ZERO
100
200
400
600
800
BLANK
10.0
20.0
40.0
60.0
80.0
5N Sulufuric Acid:
Dilute 70 ml of conc. sulfuric acid to 500 ml.
Potassium antimonyl tartarate - K(SbO)C4H4O6.1/2 H2O:
The bottle of the solid salt may be labeled as: Potassium antimoy(III) oxitartarate,
or Antimony Potassium Tartarate.
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL
Dissolve 1.3715 g in 400 ml H2O, Dilute to 500 ml. Store in glass bottle.
4% Ammonium Molybdate - (NH4)6 Mo7O24.4H2O:
Dissolve 20 g in 500 ml. Stir for sometime (HARD TO DISSOLVE !!)
Store in glass stoppered bottle.
Ascorbic Acid:
Dissolve 1.76 g in 100 ml H2O.
This solution is stable for ONE WEEK ONLY at 4 degrees C.
Combined Reagent:
For 100 ml of the combined reagent add the following, IN ORDER:
- 50 ml of 5N sulfuric acid.
- 5 ml Potassium antimonyl tartarate. STIRR THOROUGHLY
- 15 ml Ammonium Molybdate. STIRR THOROUGHLY
- 30 ml Ascorbic acid. STIRR THOROUGHLY
- Let the reagent cool down to room temperature.
This combined reagent is stable for 4 HOURS ONLY !!!
PROCEDURE:
- Take 25 ml sample in a 50-ml graduated tube
- Add 4 ml combined reagent.
- Cover the tube with parafilm and shake well.
- Wait for blue color to develop. It needs 10-30 minutes time.
- Measure absorbance on the Spectronic-21 at the wavelength 880 nm.
Results:
The amount of phosphate present in waste water…………
CE6611-ENVIRONMENTAL ENGINEERING LABORATORY MANUAL