GOVERNMENT ENGINEERING COLLEGE

RAICHUR – 584 135.

DEPARTMENT OF CIVIL ENGINEERING

Environmental Engineering
Laboratory Manual

List of Experiment

B.E. CE V-Semester

BCV-504

Prof: FARHEEN TABASSUM

Page 1 of 36
 Environmental Engineering Lab

1. Preparation chemical solutions required for analysis and sampling methodologies

2. Determination of pH, Conductivity, TDS and Turbidity.
3. Determination of Acidity and Alkalinity
4. Determination of Calcium, Magnesium and Total Hardness.
5. Determination of Dissolved Oxygen
6. Determination of BOD.
7. Determination of Chlorides
8. Determination of percentage of % of available chlorine in bleaching powder sample,
Determination of Residual Chlorine and chlorine demand.
9. Determination of Solids in Sewage: i) Total Solids, ii) Suspended Solids, iii) Dissolved Solids, iv)
Volatile Solids, Fixed Solids v) Settleable Solids.
10. Determination of optimum coagulant dosage using Jar test apparatus.
11. Determination Nitrates and Iron by spectrophotometer

Demonstration Experiments ( For CIE )

1. Determination of COD (Demonstration)

2. Air Quality Monitoring (Demonstration)
3. Determination of Sound by Sound level meter at different locations (Demonstration)

LIST OF Equiments

1. pH meter,
2. Turbidity meter,
3. Conductivity meter,
4. 1. Hot air oven,
5. Muffle furnace,
6. Dissolved Oxygen meter,
7. U – V visible spectrophotometer,
8. Reflux Apparatus,
9. Jar Test Apparatus,
10. BOD incubator.

Page 2 of 36
 DETERMINATION OF pH

AIM: To measure the pH in a given water sample.

APPARATUS: Digital pH meter
REAGENTS
Preparation of buffers: Prepare buffer solution (7 pH & 4pH) with buffer tablets by
dissolving in 100 ml distilled water separately in 7pH and 4 pH. The buffer solutions last for
4-5 months.

PRINCIPLE:
pH is determined by measurement of the electromotive force of a cell comprising an
indicator electrode (an electrode responsive to hydrogen ions) immersed in the test
solution and a reference electrode is usually achieved by means of liquid junction, which
forms a part of the reference electrode. The EMF of this cell is measured with pH meter.
THEORY
1) pH is defined as: pH = - log[H+].
2) It is a measure of hydrogen ion, i.e., [H+] concentration in water.
3) Neutral pH, i.e., pH of pure water is 7.
4) High pH (>7) means that the water is alkaline.
5) Low pH (<7) means that the water is acidic.
6) pH is measured using pH electrode
7) The pH electrode consists of a reference electrode, and glass electrode sensitive or
pervious to [H+] ions only.
8) The reference electrode is indifferent to the solution conditions, and always has the
same voltage.
9) The glass electrode is sensitive to [H+] ions only. It contains a solution with fixed [H+]
concentration.
10) When the glass electrode is dipped in a solution, depending on the concentration of
[H+] ions in the solution, [H+] ions either flow out of the bulb into the solution, or flow
into the bulb from the solution.
11) The potential difference, which causes this current, is measured by a device known as
the pH meter.

Page 3 of 36
CALIBRATION OF THE INSTRUMENT:

Calibration is done as under-

1. Set the temperature knob to the buffer solution temperature.
2. Dip the electrode on 7 pH solution
3. Set the display value to 7 pH by turning CAL knob.
4. Dip the electrode in the 4 pH solution after washing it with distilled water.
5. Set the display to 4 pH by rotating slope knob
6. Instrument is ready for measurement of any solution.
PROCEDURE:

To measure the pH value of the given solution,

1. Wash the electrode with distilled water and clean with filter paper.
2. Take the solution in a clean glass beaker and immerse the electrodes in it.
3. Measure the temperature of the solution and adjust the temperature compensator to
that value. Set the range control in the expected range.
4. Turn the control from stand by to READ position. The reading shown in the
appropriate scale of the meter is the pH value of the given solution
CALCULATIONS
The pH value is obtained directly from the instrument.

S.NO SampleName ObservedPHValue

1
2
3
4
5

RESULTS:
The pH of the given sample is

Page 4 of 36
 DETERMINATION OF CONDUCTIVITY
AIM: To determine the specific conductivity of the given sample.

APPARATUS
Digital conductivity meter

REAGENTS
Standard KCl Solution: Dissolve 0.7456 gms of Potassium Chloride(dried at 180 0C for 1
hour) in distilled water and dilute to 1000 ml. The specific conductance of this solution at
250C is 1408 S/Cm.

THEORY
The conductivity of the water is its capacity to carry an electrical current and varies both
with number and types of ions the solution contains, which in turn is related to the
concentration of ionized substances in the water. Most inorganic substances in water are in
the ionized form and hence contribute to conductance. The unit of specific conductivity is
micro Siemens per Cm (S/Cm).

PRINCIPLE
The specific conductivity is measured by employing the wheat-stone bridge principle. The
cell and temperature probes of the instruments are dipped into the given sample to find
the specific conductivity of the given sample. The specific conductivity multiplied by a
conversion factor gives the total dissolved solids.

CELLCONSTANT VERIFICATION

Checking the cell constant as per the following procedure is recommended before any
measurement.
1. Set the ‘Function’ switch to check position & adjust the display to 1.000 with CAL
control.
2. Dip the Conductivity cell in a solution of known value.
3. Adjust the temperature control to the temperature of the solution. (not required when
measuring in ATC mode)
4. Move the Function switch to Cond. Position and Range switch to appropriate range.
5. Adjust the cell constant knob so that the display reads the known value of the solution.
6. Bring the Function switch to Cell Const. position.
7. The display shows the cell constant of the conductivity cell.
PROCEDURE

1. Rinse the conductivity cell with solution whose conductivity is to be measured.

2. Dip the conductivity cell in the solution under test

Page 5 of 36
 3. Set the function switch to check position
4. Display must read 1.000. If it doesn’t , set it with CAL control provided at the back panel.
5. Put function switch to cell constant position and set the cell constant control to the cell
constant value of the conductivity cell
6. Move the function switch to the COND. Position and switch to appropriate range
7. Connect the conductivity cell at the rear of the instrument
8. Set the temperature control to the temperature of the solution
9. Bring the range switch at a position where maximum resolution is obtained
10. Read the display
11. This would be the exact conductance of sample at 250C.
CALCULATIONS
The EC value is obtained directly from the instrument.

S.NO SampleName ObservedECValue

1
2
3
4
5

RESULT

The specific conductivity of the given sample = S/Cm

Page 6 of 36
 DETERMINATION OF TOTAL DISSOLVED SOLIDS

AIM: To determine the total solids present in the given water sample.

APPARATUS

1. Evaporating Dishes
2. Oven
3. Muffle Furnace
4. Desiccator
PRINCIPLE

Residue after the evaporation and subsequent drying in oven at specific temperature 103
– 1050 C of a known volume of sample are total solids. Whereas loss in weight on ignition
of the same sample at 5500 C in which organic matter is converted in to CO2 & H2O while
temperature is controlled to prevent decomposition and volatilization of inorganic matter
as much as consistent with complete oxidation of organic matter, are volatile solids.

PROCEDURE

1. Take a known volume of a well mixed sample in a tared (W 1) dish ignited to

constantweight.
2. Evaporate the sample at 1030C for 24 hours.
3. Cool in desiccator, weigh and record the reading (W2).
4. Ignite the dish for 15 – 20 min. in a muffle furnace maintained at 550 ± 500C.
5. Cool the dish partially in air until most of heat has been dissipated and then in
desiccators and record final weight (W3).

CALCULATIONS
(W2 – W1) x 1000
Total solids = ---------------------
ml of sample
W1 = Initial weight of the dish in mg.
W2 = Final weight of the dish in mg.
(W2 – W3) X 1000
Total Volatile solids = -----------------------------
ml of sample
W3 = weight of the dish after drying in muffle furnace.

RESULT: Total Dissolved solids in given water sample is mg/l.

Page 7 of 36
 DETERMINATION OF TURBIDITY
AIM: To determine the turbidity of the given sample.

APPARATUS: Nephelo – Turbidity meter with sample cell

REAGENTS FOR CALIBRATION OF THE INSTRUMENT:

Solution 1: Dissolve 1 gm Hydrazine Sulphate (NH2)2H2So4 (carcinogen) in distilled water
and dilute to 100 ml in a volumetric flask
Solution 2: Dissolve 10 gms Hexamine LR grade (CH2)2N4 in distilled water and dilute to
100 ml in a volumetric flask
Take 12.5 ml of solution 1 and 12.5 ml of solution 2 in a 100 ml volumetric flask and dilute
to 100 ml, allow to stand for 24 hours at 250C. the turbidity of this suspension is 1000
Nephelometric Turbidity Unit (NTU).

THEORY:

Turbidity is an expression of optical property that uses light scattering properties of

suspension in the sample. Turbidity in water is caused by suspended matter such as
clay, silt, finely divided organic and inorganic matter soluble, colored organic
compounds, plankton and other microscopic organisms.
Turbidity is measured by shining light through a sample and measuring the degree of
scattering as measured by a light detector placed at right angles to the original light
path. Above measuring technique is known as Nephelometry.
Turbidity can also be measured by shining light through a sample and measuring the
degree of light penetration as measured by a light detector placed in line to the original
light path. This measuring technique is known as Turbidimetry.

PRINCIPLE

Nephelo-Turbidity meter operates on the principle that light passing through a

substance is scattered by matter suspended in the substance. In this instrument, a
strong light beam is passed upward through a tube containing the sample. As the beam
passes through the sample, the light is scattered in proportion to suspended particles.
At 900 to the light path, this scattered light is sensed by the phototube to give the
turbidity reading. The unit of measurement is NTU.

CALIBRATION OF THE INSRTRUMENT

1. Switch on the instrument and keep it ON for some time.

2. Select appropriate range depending upon the expected turbidity of the sample.
3. Set zero of the instrument with turbidity free water using blank solution and adjust
000 with the ‘set zero’ knob. The CAL control should be moved by 5 turns clockwise
from 0 position.
4. Now in another test tube, take standard suspension that already prepared. For 0-200
NTU range use 100 NTU solution and for higher range use 400 NTU solution as
standard.
Page 8 of 36
PROCEDURE
1. Take the test tube containing distilled water in the test tube holder and close the test
tube holder lid.
2. Select the required range for measurement.
3. Adjust the display to 000 by adjusting ‘set zero’ knob.
4. Remove the test tube containing distilled water & insert another test tube containing
standard solution (say 400 NTU). Place it in the test tube holder.
5. Take the measurement of the solution suspension& adjust the ‘calibrate’ knob so that
the display reads the selected standard solution value.
6. Again check the display zero with the test tube containing distilled water.
7. Now the instrument is ready to take measurement of any unknown suspension.

RESULTS

Turbidity of the given sample of water = NTU

Page 9 of 36
 DETERMINATION OF ACIDITY

AIM: To determine the acidity in the given water and waste water samples.

APPARATUS
Burette, Pipette, conical flasks, volumetric flasks and beakers
REAGENTS
1. 0.02N NaOH Solution: Dissolve 0.8g of NaOH in distilled water and dilute to 100ml
2. Methyl orange indicator: Dissolve 50g of methyl orange powder in distilled water
and dilute to 100ml
3. Phenolphthalein indicator: Dissolve 1g of phenolphthalein in 100ml of 95% ethyl
alcohol or isopropyl alcohol, and add 100ml of distilled to it and 0.02N NaOH
solution drop wise until faint pink colour appears.
PRINCIPLE

Hydrogen ions present in a sample as a result of dissociation or hydrolysis of solutes are

neutralized by titration with standard alkali. The acidity thus depends upon the end point
pH or indicator used.

PROCEDURE
1. Pipette out 25 ml of sample into conical flask. Add 2 drops of methyl orange indicator
to the sample solution.
2. Titrate the sample solution against 0.02N sodium hydroxide solution. The end point is \
Noted when change from orange red to yellow colour.
3. Add two drops of phenolphthalein indicator and continue the titration till a pink colour
Formation. Note down the volume of the titrant used.
OBSERVATIONS AND CALCULATIONS
Burette solution: NaOH
Pipette solution: Sample
Indicator: Methyl orange, Phenolphthalein
End Point: Yellow, Pink

S.No Volume of Burette reading Volume

sample(ml) of NaOH
Initial (ml) Final (ml) (ml)

Methyl orange acidity due to mineral acids (as CaCO3) = (V1*N of NaOH *50,000)/Vol. of
sample
Phenolphthalein acidity = Total acidity (as CaCO3) = (V2*N of NaOH *50,000)/Vol. of sample

RESULT
Methyl orange acidity =
Phenolphthalein acidity =
Total acidity =
Page 10 of 36
 DETERMINATION OF ALKALINITY

AIM: To determine the alkalinity present in a given water sample.

APPARATUS
1. Burette
2. Pipette
3. Conical flask
4. Glazed tile

REAGENTS
1. Sulphuric acid 0.02 N
2. Methyl orange indicator
3. Phenolphthalein indicator

THEORY
The alkalinity of water is a measure of its capacity to neutralize acids. Although many
materials may contribute to the alkalinity of the water, the major portion of the
- --
alkalinity in natural waters is caused b),y Hydroxides(OH

Carbonates(CO3 ),

-
Bi- carbonates(HCO3

Alkalinity values provide guidance in applying proper doses of chemicals in water and waste
water treatment processes, particularly in coagulation, softening and operational control
of anaerobic digestion.

PRINCIPLE
Alkalinity of sample can be estimated by titrating with standard H2SO4. Titration to
pH 8.3 or decolorization of phenophthalein indicator will indicate complete

neutralization of OH and ½ of CO3 while to pH 4.5 or sharp change from yellow to

orange of methyl orange indicator will indicate total alkalinity (complete neutralization
of OH, CO3, and HCO3).

pH 0 4.5 8.3 14.0

Indicator Methyl orange Phenolphthalein

Page 11 of 36
 PROCEDURE

1. Take 20ml sample in a conical flask and add 2-3 drops of Phenolphthalein indicator.
2. If pink color develops titrate with 0.02 N H2SO4 till itdisappears indicating pH 8.3. Note the
volume of H2SO4 required.
3. Add 2-3 drops of Methyl orange to the same flask. The sample turns yellow / red. Continue
titration till yellow / red colour changes to orange indicating pH 4.4 – 4.5. Note the volume
of H2SO4 required.
4. In case pink colour does not appear after addition of phenolphthalein continue as in 3
above.
Calculate total (T), Phenolphthalein (P)and Methyl orange (MO) alkalinity as followsand
express as mg / l as CaCO3.

OBSERVATIONS
Phenolphthalein indicator Methyl orange indicator
Burette reading Burette reading
Volume
of H2SO Volume of
S. No. Volume H2SO4 Remarks
Of sampl e Initial Final 4 Initial Final
run down
(ml) (ml) (ml) Run down (ml) (ml)
(ml)
(ml)

CALCULATIONS
Phenolphthalein alkalinity (P) mg/l as CaCO3 = A x 1000/ml of sample takenMethyl Orange
alkalinity (M) mg/l as CaCO3 = B x 1000/ml of sample taken
Total alkalinity (T) mg/l as CaCO3 = (A+B) x 1000/ml of sample taken

In case H2 So4 is not 0.02N apply the following formula:

A/B*N*50000
Alkalinity, Mg/l as CaC03= ---------------------
Ml of sample

Where, A=ml of H2S04 required to bring the pH to 8.3

B= ml of H2S04 required to bring the pH to 4.5
N= Normality of H2So4 used.

RESULT:

Alkalinity of given water sample is ----------- mg/l

Page 12 of 36
 DETERMINATION OF HARDNESS
(TOTAL,CALCIUMAND MAGNESIUM HARDNESS)
AIM
Todetermine the amount of Total Hardness present In a given water sample by
EDTAT itration method.
APPARATUSUSED
1. Pipette
2. Conicalflask
3. Burette
4. Beaker
5. Dropper
PROCEDURE
1. Open the simulation of hardness of water, go through the given Description and Solutions
used and click on NEXT button shown at the bottom right corner.
2. Place the funnel in the burette to add 200ml test sample.
3. Open the lid and pour EDTA solution on to the burette upto zero mark.
4. Remove the funnel.
5. Squeeze the pipette bulb to take the CaCO3 solution up into the pipette.
6. release liquid into the beaker.
7. Note the addition of 10ml 0.01M Calcium carbonate solution to conical flask.
8. add ammonia buffer solution through pipette to the conical flask.
9. add 5-6 drops of E. B.T indicator to the conical flask.
10. Observe the colour change of solution to wine red
11. Titrate ETDA solution into the conical flask till the colour changes to blue.
12. Calculate CaCO3 equivalent to 1ml of ETDA using the formula.
13. Repeat the same procedure for the 100ml of water sample. Calculate the total hardness of
water using the formula.
CALCULATIONS

Burette Reading (ml)

Volume of calcium Volume of EDTA
S.No carbonate (ml) (Finalvalue–
Initial Final
solution (CaCO3) Initial value)
in ml
1

CaCO3 equivalent to1ml of EDTA = 𝑣𝑜𝑙𝑢𝑚𝑒𝑜𝑓CaCO3

𝑣𝑜𝑙𝑢𝑚𝑒𝑜𝑓𝐸𝐷𝑇𝐴

Page 13 of 36
 DETERMINATION OF DISSOLVED OXYGEN (WINKLER METHOD)

AIM
To find out the dissolved oxygen in a given water sample

SPECIAL APPARATUS
1. Burette
2. Burette stand
3. 300 ml glass stoppered BOD bottles
4. 500 ml conical flask
5. Pipettes with elongated tips
6. Pipette bulb
7. 250 ml graduated cylinders
8. Wash bottle

CHEMICALS REQUIRED
1. Manganous sulphate solution
2. Alkaline iodide-Azide solution
3. Sulfuric acid
4. Concentrated
5. Starch indicator solution
6. Sodium thiosulphate
7. Distilled or deionized water
8. Potassium Hydroxide
9. Potassium Iodide
10. Sodium Azide

REAGENTS PREPARATION

Manganous Sulphate
Dissolve 480 g MnSO4.4H2O, 400 g MnSO2.2H2O or 364 g MnSO4.H2O in distilled water, filter and
dilute to 1 litre. 50

Alkali iodide-azide reagent.

Dissolve 500 g NaOH or 700 g KOH and 135 g NaI or 150 g KI in distilled water and dilute to 1 litre. Add
10 g sodium azide (NaN3) dissolved in 40 mL distilled water. The reagent should not give colour with
starch when diluted and acidified.

Starch indicator:
Add cold water suspension of 5 g soluble starch to approximately 800 mL boiling water with stirring.
Dilute to 1 litre, allow to boil for a few minutes and let settle overnight. Use supernatant liquor.

Stock sodium thiosulphate, 0.1N:

Dissolve 24.82g Na2S2O3.5H2O in distilled water. Preserve by adding 0.4g solid NaOH or 1.5mL of 6N
NaOH and dilute to 1000mL.
Page 14 of 36
Standard sodium thiosulphate, 0.025N:
Dissolve 6.205 g sodium thiosulphate (Na2S2O3.5H2O) in freshly boiled and cooled distilled water and
dilute to 1 litre. Preserve by adding 5 mL chloroform or 0.4 g NaOH/L or 4 g borax and 5 to 10 mg
HgI2/L. Standardise this with 0.025 N potassium dichromate solution which is prepared by dissolving
1.226 g potassium dichromate in distilled water and diluted to 1 litre.

Standardisation of 0.025 N sodium thiosulphate solution:

Dissolve approximately 2 g KI in an Erlenmeyer flask with 100 to 150 mL distilled water. Add 10 mL of
H2SO4, followed by exactly 20 mL, 0.1 N potassium dichromate solution. Place in the dark for 5
minutes, dilute to approximately 400 mL and titrate with 0.025 N sodium thiosulphate solution,
adding starch towards the end of titration. Exactly 20 ml 0.025 N thiosulphate will be consumed at the
end of the titration. Otherwise, the thiosulphate solution should be suitably corrected.

PROCEDURE
1. Take two 300-mL glass stoppered BOD bottle and fill it with sample to be tested. Avoid any kind
of bubbling and trapping of air bubbles.
2. Add 2mL of manganese sulfate to the BOD bottle by inserting the calibrated pipette just below
the surface of the liquid.
3. Add 2 mL of alkali-iodide-Azide reagent in the same manner.
4. Squeeze the pipette slowly so no bubbles are introduced via the pipette (The pipette should be
dipped inside the sample while adding the above two reagents. If the reagent is added above the
sample surface, you will introduce oxygen into the sample).
5. If oxygen is present, a brownish-orange cloud of precipitate or flock will appear.
6. Allow it to settle for sufficient time in order to react completely with oxygen.
7. Add 2 mL of concentrated sulfuric acid via a pipette held just above the surface of the sample.
8. Carefully stopper and invert several times to dissolve the floc.
9. At this point, the sample is "fixed" and can be stored for up to 8 hours if kept in a cool, dark place.
10. Rinse the burette with sodium thiosulphate and then fill it with sodium thiosulphate. Fix the
burette to the stand.
11. Measure out 203 mL of the solution from the bottle and transfer to an conical flask.
12. Titration needs to be started immediately after the transfer of the contents to conical flask.
13. Titrate it against sodium thiosulphate using starch as indicator. (Add 3 – 4 drops of starch
indicator solution)
14. End point of the titration is first disappearance of the blue color to colorless.
15. Note down the volume of sodium thiosulphate solution added which gives the dissolved oxygen

CALCULATIONS

SODIUMTHIOSUPHATE VS POTASSIUM CHROMATE

Volumeof
Nameof Burettereading(ml) Na2S2O3.5H2O
S.No water
sample consumed
sample
Initial Final
1
2
3

Page 15 of 36
 N1V1=N2V2

Where
N1 = Normality of potassium dichromate
V1 = Volume of potassium dichromate
N2 = Normality of sodiumthiosulphate
V2 = Volume of potassium sodiumthiosulphate

Volume of Volume of sodium

Name Burette reading (ml)
S.No water thiosulphate
of
sample Initial Final Consumed (ml)
sample
1
2
3
Dissolved oxygen = Volume of sodiumthiosulphate consumed × N ×1000
Volume of sample taken

RESULT
1. The DO present in a given water sample-1 is = ppm
2. The DO present in a given water sample-2 is = ppm

Page 16 of 36
 DETERMINATION OF BIOCHEMICAL OXYGEN DEMAND
Aim: todetermine the BOD in given water sample.
Apparatus:
1. BOD bottles (capacity 300 ml)
2. Sampling device for collection of samples
3. Burette
4. Pipettes.
5. Incubator
REAGENTS:
1. Ferric Chloride
2. Phosphate buffer solution
3. Magnesium sulfate solution
4. Calcium chloride solution
5. Sodium sulfite solution 0.025N
PROCEDURE
1. Place the desired volume of distilled water in a 5-liter flask. Aeration is done by bubbling
compressed air through water.
2. Add 1 ml of phosphate buffer, 1 ml of magnesium sulfate solution, 1 ml of calcium
chloride solution and 1 ml of ferric chloride solution for every liter of distilled water
(dilution water).Mixwell.
3. In the case of the waste water which are not expected to have sufficient bacterial
population, add seed to the dilution water. Generally, 2 ml of settled sewage is sufficient
for 1000 ml of dilution water.
4. Highly acidic or alkaline sample are to be neutralized to a pH of 7.0
5. Add 2 to 3 ml of sodium thio -sulfate solution to destroy residual chlorine if any.
6. Take sample as follows.
Strong wastes : 0.1 to 1%
Settle domestic sewage : 1 to 5%
Treated effluents : 5 to 25%
River water : 25 to 100%.
7. Dilute the sample with the distilled water and mix the contents well.
8. Take diluted sample into 2 BOD bottles.

Page 17 of 36
 9. Fill another two BOD bottles with diluted (distilled) water alone.
10. Immediately find D.O. of a diluted wastewater and diluted water (distilled water).
11. Incubate the other two BOD bottles at 200 C for 5 days. They are to be tightly
stopperedto prevent any air entry into the bottles.
12. Determine D.O content in the incubated bottles at the end of 5 days (120 hours).
OBSERVATIONS

Volume of Burette Readings Volume of

S.No. D.O in
Sample Initial Final Na2S2O3 run
(mg/l)
(ml) (ml) (ml) down
(ml)

CALCULATIONS

Initial D.O. of diluted sample = Do

D.O at the end of 5 days for the diluted sample = D5

Initial D.O. of distilled water (blank) = Co

D.O. at the end of 5 days for the distilled water (blank) = C5

D.O. depletion of dilution water = C o - C5

D.O. depletion of the diluted sample = Do - D5

D.O. depletion of due to microbes = (Do - D5) - (Co -

C5)

BOD of the sample at 200 C = [(Do - D5) x Vol. of the Bottle] - (Co - C5)
X ml of the sample

RESULTS:

Bio-Chemical Oxygen Demand for the given sample = mg/l

Page 18 of 36
 DETERMINATION OF CHLORIDES

AIM: To estimate the amount of chlorides present in the given sample of water.
APPARATUS
1. Pipette
2. Burette
3. Conical flask etc.
REAGENTS
1. Potassium chromate (K2CrO4) indicator
2. Silver nitrate (AgNO3) of 0.0141N
THEORY

Chlorides occur widely in water and waste water and are usually associated with
sodium ion. Although chlorides are not harmful, concentrations beyond 250 mg/l
impart a peculiar taste to water, rendering it unacceptable from aesthetic point
of view for drinking purpose. Presence of chlorides above the usual background
concentration in water sources is also used as an indicator of pollution by
domestic sewage.
PRINCIPLE

Chlorides ion is determined by titration with standard AgNO3 in which AgCrO4

precipitatesout. The end of titration is indicated by formation of red silver
chromate from excessAgNO3 and potassium chromate used as an indicator in neutral
to slightly alkaline solution.

PROCEDURE

1. Adjust the pH of sample between 7.0-8.0.

2. Standardize AgNO3against standard NaCl solution.
3. Take 20ml well mixed sample and add 1.0ml of K2CrO4.
4. Titrate with standard AgNO3 solution till AgCrO4 starts precipitating.
5. For better accuracy titrate 20ml of distilled water in the same way to
establish reagentblank.

OBSERVATIONS
Volume Burette reading Volume of
S. No. o Initial AgNO3 Remarks
(ml) Final (ml)
fsample run down (ml)
(ml)

Page 19 of 36
 CALCULATION
Chlorides (Cl-) in mg/l = (A-B)xNx35.45/ml of sample
Where A = ml of AgNO3 run down for the
sample
B = ml of AgNO3 run down for the
blankN = Normality of AgNO3
used
RESULT
Chlorides present in the given sample = mg/l

Page 20 of 36
 DETERMINATION OF RESIDUAL CHLORINE
AIM
To determine the amount of chloride present in the given sample

PRINCIPLE

The amount of chloride present in water can be easily determined by titrating the
given water sample with silver nitrate solution. The silver nitrate reacts with chloride
ion according to1 mole of AgNO3 reacts with 1 mole of chloride. The titrant
concentration is generally 0.02 M. Silver chloride is precipitated quantitatively,
before red silver chromate is formed. The end of titration is indicated by formation
of red silver chromate from excess silver nitrate. The results are expressed in mg/l of
chloride (Cl- with a molecular weight of 35.453 g/mol).

APPARATUS REQUIRED
1. Burette with stand
2. Pipette
3. Conical flask measuring jar etc.,

CHEMICALS REQUIRED
1. Sodium Chloride
2. Silver nitrate
3. Potassium Chromate

REAGENTS PREPARATION
Standard silver nitrate solution 0.0141 N:
Dissolve 2.395 g AgNO3 in distilled water and dilute to 1 litre. Standardise against 0.0141 N
NaCl. Store in a brown bottle

Standard sodium chloride 0.0141N:

Dissolve 824.1 mg NaCl (dried at 140°C) in chloride free water and dilute to 1 litre.

Potassium Chromate Solution (K2CrO4)

Dissolve 1 gm of potassium chromate in 20m1 of distilled water.

PROCEDURE

Standardization of Silver Nitrate Solution

1. Pipette 20 ml of sodium chloride solution in to the conical flask.
2. Add one or two drops of potassium chromate solution.
3. Titrate against Silver Nitrate solution until the appearance of reddish brown colour
4. Re peat the titration for concordant values.

Silver Nitrate Vs Sample -

1. Pipette 20 ml of sample in the conical flask.
2. Add one or two drops of potassium chromate solution

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3. Titrate against silver Nitrate solution until the appearance of reddish brown colour.
4. Repeat the titration for concordant values.

CALCULATIONS

SILVERNITRATEVSSODIUM CHLORIDE

Nameo Volume of Burettereading(ml) AgNO3

S.No
f watersample consumed
sample Initial Final
1
2
3

N1V1=N2V2
Where
N1=Normality of NaCl,
V1 = Volume of NaCl,
N2=Normality of silver nitrate
V2 = Volume of silver nitrate

SILVERNITRATEVSSAMPLE

Volume of
Name of Burette reading(ml) Ag NO3
S.No water
sample consumed
sample
Initial Final
1
2
Chlorides = Volume of AgNO3 × Normality AgNO3×35.45 ×1000
Volume of sample taken

RESULT

1. The phenolphthalein alkalinity present in a given water sample-1 is = ppm

2. The phenolphthalein alkalinity present in a given water sample-2 is = ppm

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 DETERMINATION OF SOLIDS IN SEWAGE

TOTAL SUSPENDED SOLIDS

AIM: To determine the total suspended solids of the given sample.

APPARATUS

1. Evaporating Dishes
2. Oven
3. Muffle Furnace
4. Desiccator
5. What’s man filter paper for TSS and GF Filter paper for Volatile Suspended solids.

PRINCIPLE

Non filterable residue left on the filter paper and further dried at 1030C –
1050C are suspended solids and the loss in weight of the filter paper ignited at
5500C are volatile suspended solids.

PROCEDURE

1. Take known volume of a sample in a beaker.

2. Pour on the filter paper which is already weighed (W1).
3. After filtration keep filter paper in an oven at 1050C for one hour
4. Cool in a desiccator and take final weight (W2).
5. Ignite the GF filter paper in a muffle furnace at 550 0C for 15 – 20 minutes.
6. Cool the dish partially in air until most of heat has been dissipated and
then in adesiccator and record (W3).

CALCULATIONS
(W2 – W1) X 1000
Total suspended solids = -------------------------
ml of sample

(W2 – W3) X 1000

Volatile suspended solids = -----------------------
ml of sample

RESULT: Total Suspended solids in given water sample is mg/l.

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TOTAL DISSOLVED SOLIDS

AIM: To find the total dissolved solids in a given sample.

APPARATUS:
Crucible, filter paper and hot air oven.

PROCEDURE:

Take an evaporating dish, heat it in the oven to remove the moisture, place it in a
dissector to balance the temperature and take the initial weight W1. Take known
volume of well mixed sample and filter it from a filter paper which is previously dried
and weighed evaporating dish. The filtrate left over in an evaporating dish is dried at
1030C and desiccated for balancing the temperature and weight take the final
weight W2.

OBSERVATION AND CALCULATIONS:

Empty weight of evaporating dish, W1= g.
Weight of sample with dish after filtration (after oven drying), W2 = g
Volume of sample= ml
Total dissolved solids = ((W2-W1)×1000×1000)/ (volume of sample). = mg/l.

RESULT:
Total dissolved solids = mg/l.

TOTAL FIXED AND VOLATILE SOLIDS

AIM: To find out Total fixed and volatile solids of the given sample

PRINCIPLE:
Total volatile solids and fixed solids are determined as residue remaining after
evaporation, drying at 1030 C and ignition at 6000C.

APPARATUS:
1. Evaporating dish.
2. Oven 1030C
3. Muffle furnace 6000C
4. Desiccators
6. Water Bath

PROCEDURE:
1. A clean porcelain dish is ignited in a muffle furnace and after partial cooling in air, it
is cooled in a desiccators and weighed (W1).

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 2. A 100 ml of well mixed sample (graduated cylinder in rinsed to ensure transfer of all
suspended matter) is placed in the dish and evaporated at 1000C on water bath,
followed by drying in oven at 1030C for 1 hour.
3. Dry to a constant weight at 1030C, cool in desiccator and weighed (W2).
4. Ignite the residue on evaporation at 6000C in the muffle furnace to constant weight
in 10 to 15 min.
5. Allow the dish to cool and moisten the ash with a few drops of distilled water.
6. Dry to constant weight at 1040C, cool in a desiccators and weighed (W3).

CALCULATIONS:
Total solids (mg/l) = ((W2-W1)×1000×1000)/ (volume of sample).= mg/l.
Total volatile solids (mg/l) = Total solids-Fixed solids. = mg/l.
Total fixed solids (mg/l) = ((W3-W2)×1000×1000)/ (volume of sample). = mg/l.

OBSERVATIONS:

Type of Sample Volumeof Weightof Weightof Residue

solids details sample,ml emptydish emptydish+ (mg/l)
(mg) Residue
(mg)

RESULTS:
The amount of Total, fixed and volatile solids of the given sample is=
mg/l

CONCLUSION

TOTAL SETTLEABLE SOLIDS

AIM: To find out Total settleable solids of the given sample.

PRINCIPLE:
The particles in suspensions whose specific gravity greater than that of water will settle
under quiescent conditions.

APPARATUS:
1. Imhoff cone.
2. Holding device.

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PROCEDURE:
1. Gently fill the Imhoff cone with the thoroughly well mixed sample usually one liter
and allow it to settle.
2. After 45 minutes, gently rotate the cone between hands to ensure that all solids
adhering to the sides are loosened.
3. Allow the solids to settle for 15 minutes more, to make up for a total period of 1
hour.
4. Read the volume of the sludge which has settled in the apex.
5. Express the results in ml settleable solids per liter of sample per hour.

CALCULATIONS:
Total settleable solids (mg/l)= (ml of solids x 1000)/ml of sample.

PRECAUTIONS:
1. The imhoff cones must be cleaned with a strong soap and hot water using a brush.
2. Wetting the cone with water before use, helps in preventing adherence of the
solids to the sides.
3. The method is subjected to considerable in accuracy if the solids contain large
fragments.
4. The determination of total settleable solids should be carried out soon after
sampling in order to avoid errors through flocculation.

OBSERVATIONS:

Sample details Volume of sample taken Total settleable solids

(ml)
ml/l/hour

RESULTS: Total settlable solids of the given sample is= mg/l.

CONCLUSION:

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 DETERMINATION OF OPTIMUM DOSAGE OF COAGULANT (JAR TEST)
Aim:

To find the optimum dose of coagulant required for treating the given turbid water
sample.
APPARATUS:
1. Jar test Apparatus.
2. pH meter.
3. One liter beakers - 6 Nos.
4. Graduated pipette.
5. Turbidity meter.
REAGENTS:
Alum
THEORY:
Chemical coagulation, flocculation and sedimentation together reduce suspended
and colloidal solids, phosphorus fluorides, organic matter and certain toxicants.
Alum, ferrous and ferric salts. When used for clarification, result in producing
better effluent than by the plain sedimentation. The exact doses of these
coagulants cannot be theoretically calculated and therefore, laboratory tests have
to be carried out using the jar test procedure. This enables the investigations of
such inter related factors like pH, color, turbidity, mineral matter, temperature,
time of flocculation and the degree of agitation, which will control the coagulation
and flocculation.

PROCEDURE:
1. Using 200 ml of sample on a magnetic stirrer, add coagulant in small increments at
a pH
6. After each addition, provide a 1 minute rapid mix followed by a 3 min. slow
mix.Continue addition until a visible floc is formed.
2. Using this dose place 1000 ml sample in each of six beakers.
3. Adjust the pH to 4.0, 5.0, 6.0, 7.0, 8.0 and 9.0 with standard alkali acid.
4. Rapid mix each samples for 1 min. follow this with 14mi. flocculation at slow speed.
5. Measure turbidity or pertinent effluent concentration of each settled sample.
6. Plot the percent removal of characteristics versus pH and select the optimum pH.
7. At this pH repeat steps 2,4, and 5 varying the coagulant dosage.
8. Plot the percent removal Vs. the coagulant dosage and select the optimum dosage.

OBSERVATION:

Raw water turbidity (NTU)= Raw water pH =

Raw water Alkalinity (mg/l)=

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 TABULATION:
Sl. Vol. of Beaker Weight of Initial Final turbidity
No sample No. alumadded turbidity turbidity removed
NTU NTU
1
2
3
4
5
6
RESULTS
The optimum dosage of coagulant for the given sample is mg/l.

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 DETERMINATION OF NITRATES AND IRON BY SPECTROPHOTOMETER

AIM:To Determine the quantity of iron present in the given sample of water using
1, 10 -phenanthroline method

APPARATUS: UV Spectrophotometer, Sample Tubes.

REAGENTS: Acid Phenanthroline Indicator, Iron Reducing

Reagent.

THEORY:

Iron is usually present in natural water and is not objectionable, if concentration is less
than
0.3 ppm. It may be in true solution in colloidal state that may be peptized by
organic matter, in the inorganic and organic iron complexes, or in relatively coarse
suspended particles. It may be ferrous or ferric, suspended or filterable. Iron exists
in soils and minerals mainly as insoluble ferric oxide and iron sulphide (pyrite). It
occurs in some areas, also as ferrous carbonate (siderite), which is very slightly
soluble.

PRINCIPLE:

The phenanthroline method is the preferred standard procedure for the

measurement of iron in water except when phosphate or heavy metal
interferences are present. The method depends upon the fact that 1, 10-
phenanthroline combine with Fe++ to form an orange-red complex. Its colour
conforms to Beer’s law and is readily measured by visual or photometric
comparison. Small concentration of iron can be most satisfactorily determined by
colorimetric analysis. It is also based on Beer’s law. By measuring the intensities of
transmitted and incident light through a coloured solution and knowing its optical
density or transmission, we can prepare a calibration curve and subsequent
concentration can be read.

PROCEDURE:
Use universal sample holder.
1. Press and hold ON button until spectrophotometer turns on.
2. Scroll to and select PROGRAMMED TESTS.
3. Scroll to and select ALL TESTS (or another sequence containing53 Iron Phen)
from TESTING MENU.
4. Scroll to and select 53 Iron Phen from menu.

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 5. Rinse a clean tube (0290) with sample water. Fill to the 10 mL mark withsample.
6. Insert tube into chamber, close lid and select SCAN BLANK.
7. Remove the tube from Spectro. Remove the cap and add 6 drops of
*AcidPhenanthroline Indicator (2776). Cap and invert the tube 4 times to mix
reagents. Wait five minutes for maximum color development.
8. After five minutes, mix, insert tube into chamber, close lid and select
SCANSAMPLE. Record result as ppm Ferrous Iron.
9. Remove tube from Spectro. Use the 0.1g spoon (0699) to add one measureof
*Iron Reducing Reagent (2777). Cap and invert 15-20 times to mix, wait
5minutes for maximum color development.
10. After 5 minutes, mix insert tube into Spectro. Close lid and select SCAN
SAMPLE. Record result as ppm Total Iron.
11. Press OFF button to turn spectrophotometer off or press EXIT button to exit toa
previous menu or make another menu selection.
12. Total Iron (ppm) - Ferrous Iron (ppm) = Ferric Iron (ppm)

RESULT:
1. The quantity of ferrous iron present in the given sample is ppm.
2. The quantity of Total Iron present in the given sample is ppm.
3. The quantity of Ferric Iron present in the given sample is ppm.

Page 30 of 36
 DETERMINATION OF CHEMICAL OXYGEN DEMAND

Aim: todetermine the COD of the given sample.

APPARATUS:
1. Reflux apparatus
2. Hot plate / Heating mantle
3. Burette
4. Pipette
5. Measuring jars

REAGENTS:
1. Standard potassium dichromate 0.25 N
2. Concentrated sulphuric acid reagent (H2SO4)

3. Silver sulphate (Ag2SO4)

4. Standard ferrous ammonium sulphate 0.1 N
5. Ferroin indicator
6. Mercuric sulphate

PRINCIPLE:
COD test determine the oxygen required for chemical oxidation of organic matter
with the help of strong chemical oxidant. The organic matter gets oxidized
completely by potassium dichromate in the presence of sulphuric acid to produce
Co2 +H20. The excess K2Cr2O7 remaining after the reaction is titrated with
Ferrous Ammonium sulphate. The dichromate consumed gives the oxygen
required for oxidation of the organic matter.

PROCEDURE

1. Place 0.4 g of Hg So4 in a reflux flask.

2. Add 20 ml of sample. Mix well.
3. Add pumice stone or glass beads followed by 10 ml of std. K2 Cr2 O7.
4. Add slowly 30 ml of H2 So4 containing Ag2 So4 mixing thoroughly. This
slow additionalong with swirling prevents fatty acids to escape out due to high
temperature.
5. Mix well. If the color turns green, either add more dichromate and acid or take
freshsample with lesser aliquot.
6. Connect the flask to condenser. Mix the contents before heating, improper
mixing will result in bumping and sample may be blown out.
7. Reflux for a minimum of 2 hours, cool and then wash down the condenser
with distilled water.
8. Dilute for a minimum of 150 ml, cool and titrate excess K2 Cr2 O7 with 0.01 N
ferrous Ammonium Sulphate using ferroin indicatior. Sharp change from blue
green to wine red indicates end point of titration.
9. Reflux blank in the same manner using distilled water instead of sample.

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OBSERVATIONS

Volume of the Burette reading Volume of FAS

S. No. diluted Initial Final run down Remarks
sample(ml) (ml) (ml) (ml)

RESULTS:

Where, A = ml of FAS for blank B

= ml of FAS for sampleN
= Normality of FAS

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 INDOOR AIR QUALITY MONITORS

AIM
To understand how to operate the instrument and also know the basic knowledge of
indoor air quality (IAQ) monitor.

APPARATUS
Indoor air quality monitor (automatic sampler) for carbon monoxide (CO), carbon
dioxide (CO2), temperature and humidity.

INDOOR AIR QUALITY MONITOR

With 90% of our time spent indoors, determining the quality of the air we breathe
indoors is essential for good health and productivity. The IAQ monitor key indoor air
quality indicators including CO2, humidity, temperature and CO. Should these
measurements fall outside recognized guidelines; further tests can be made to
suggest an appropriate course of action. For example, ventilation studies show that
as room temperatures rise above 75°F(24°C) the ability of occupants to concentrate
can drop by up to 50% and high levels of carbon dioxide will indicate poor ventilation
that results in drowsiness and perceived stuffiness. Both situations are very common
and seriously affect productivity. Over-ventilation wastes energy and results in
increased building running costs. The Surveyor range has been designed with the
user in mind. Minimal training is required to use the instruments as the intuitive
menu system and display provide step-by-step guides for each operation that are
updated when smart probes are plugged in.

STEPS FOR SAMPLING

a. Prepare a sampling assembly.
b. Set the time constant depending upon the required averaging period.
c. Instrument can be switch on and it will display concentration.
d. Simultaneously instrument will start recording the concentration values in the
memory card.
e. Using data transfer cable (ie. RS232 cable) can download data from instrument to
personal computers.

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 DETERMINATION OF SOUND BY SOUND LEVEL METER AT DIFFERENT
LOCATION
AIM
Determination of Sound by Sound level meter at different location
THEORY
Noise level measurement procedure are processes which are followed while monitoring
sound level or acoustic energy level in specified area. These days annoying noise levels have
started to become a major threat to public health. Noise in simple terms can be defined as
unwanted or unpleasant sound which disturbs the environment and has a significant impact
on the quality of life. We all very well know how exposure to high noise level can result in
hearing impairment, headache, sleep disturbance and impaired task performance.
NOISE MEASUREMENT
Three techniques are used to measure noise in the work place and community environment
(1) Personal sound exposure meter or also known as dosimeter
(2) Sound Level Meter
(3) Tape recorders, data recorders and level recorders

TYPES OF NOISE
 Steady or Continuous Noise: It is uninterrupted noise that varies less than 5 dB-A during
the period of measurement eg Noise from house hold fan , boiler in a power house,
lathes, diesel engine ,grinder etc
 Impulsive or Impact noise :When source causes vibration for a short time eg firing from
the gun or hammer
 Intermittent/Fluctuating Noise: Large workshop number of machines are in operation,
noise levels varies from time to time or dentists drilling

SELECTION OF INSTRUMENT, SAMPLING DURATION AND SCALE

 To measure noise level, the most extensively used instrument is a Sound Level Meter
(SLM) which commonly is known as a noise meter.
 After selection of instrument, selection of sampling duration and scale is must. With
these it is also necessary to consider the parameters which we need to measure like;
Lmax, Lmin, Leq, etc.
SOUND LEVEL METER
 Sound level meter SLM consist of a microphone, electric circuit and digital display.
Microphone detects and reads minimal air pressure changes and converts them into
electric signals.
 These signals are processed by electric circuits and converted into decibels. SLM can
read noise level for one location at a time.
 While measuring noise levels it is held in an arm’s length at the ear height. It does not
matter whether microphone is point towards source.
 Sound level monitor must be calibrated before and after use.
 Every sound level meter has two modes and those are SLOW and FAST.
 It is the response rate which SLM averages before showing on screen.
 For workplace noise level monitoring it should be taken as SLOW.

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INFORMATION REQUIRED FOR NOISE SURVEY/MONITORING
 Location and Nature of work (Sketch of the measurement site, including size of the
room, machine dimensions etc.)
 Nature of work process and task
 No of workers working in noisy area
 Current control including protection devices (e.g. Personal Protection devices like ear
plugs or ear muffs)
 Community noise monitoring is required? If yes, Status of Community monitoring,
whether higher than permissible level?
 Type of sound level meter
 Operating condition during the measurement and job description
 Results of the noise assessment
 Date of assessment or monitoring
 Name and signature of the person conducting the monitoring.
NOISE LEVEL MEASUREMENT PROCEDURE
 Must be check the battery full before goes onside monitoring.
 Switch ON of equipment and wait for one minute.
 SLM has two modes of operation selection via the menu key.
 Two mode:(1) In continuous Mode (2) In Recording ModeIn continuous Mode: For only
onsite observation.
 In Recording Mode: For recording the data in sound level meter.
 Select the appropriate mode of sound level.
 Set the slow or fast time as per site condition. Slow time is applicable for normal
measurement. Fast time is applicable for specific measurement of noise like moving
train, heavy traffic etc.
 Adequate Distance (1 to 3 meter) maintain between source and equipment.
 Take reading for at least one minute at one location. Number of reading can take for
one minute intervals.
 Monitoring period should be decided in such a manner that one reading is available
after one minute of monitoring at one location.
 When we change the location, off the machine and again Switch ON of equipment.
INSTRUMENT PLACEMENT
Many factors need to be taken into account when measuring because sound levels
vary at different heights above ground level. They will also vary depending on the
distance between the measurement point and facades and obstacles. These are
some important factors for doing monitoring:
a. Away from facades
b. Away from obstacles
c. With the microphone 1.2 - 1.5 meter above ground level
d. Monitoring inside Industrial facility distance from source shall be 1.5 meter
MONITORING LOCATIONS
The locations for monitoring to assess the ambient noise levels shall be mix up of all zones
i.e. Residential, Commercial and Industrial to find the variations with different zones. The

Page 35 of 36
monitoring schedule carried out on working days and weekend to differentiate the noise
levels between normal days to weekend days. The Sampling locations should be sufficient
enough provide representative samples for the project.

COMPARISON WITH NOISE STANDARDS

Once we get the monitoring records then we can compare them with standards to
understand if noise levels are exceeding the standards and if they are then by how much. In
India, the standards extensively used are prescribed by Central Pollution Control Board
(CPCB).

NOISE LEVEL MEASUREMENT STANDARDS

 Limits or noise level standards defined by pollution control board during Day time for
Residential Noise < 55 dB and Limits during Night time for Residential Noise < 45 dB
 In industry, there are of two types Sound Monitoring & testing or Noise Level
Measurement: (A) Ambient Noise level Monitoring & (B) In-plant Noise level
Monitoring
A) Ambient Noise level standards
Ambient Noise level Monitoring or Noise pollution Measurement within industrial
zone at ambient conditions.(e.g. Near Main Gate, Near Canteen, Near Manufacturing
plant etc.) As per Central Pollution control Board (as per Factory act 1948). Limits or
acceptable noise level during Day time for Ambient Noise < 75 dB and Limits during
Night time for Ambient Noise < 70 dB.

B) In-plant Noise level standards

In-plant Noise level means Sound level measurement allocated in the plant. As per
Central Pollution control Board (as per Factory act 1948) Limits for In-plant Noise
level < 90 dB.

 The below table shows the Noise level Monitoring standards prescribed by Central
Pollution Control Board (CPCB). Noise Pollution (Regulation & Control) Rules 2000
under the provision of the Environment (Protection) Act, 1986. These rules provides
standards in respect of noise for different areas/zones of a city/town

Limitsindb(A)
Area Categoryofarea/Zone
code Day Night
Time Time
A Industrialarea 75 70
B Commercialarea 65 55
C Residentialarea 55 45
D Silencezone 50 40

Day time : 6:00 AM to 10:00 PM

Night time : 10:00 PM to 6:00 AM

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