waste water testing

1. BY
FARAH NAZ

2. Analysis of waste water
parameters
 By
Farah Naz

3. WASTE WATER
 Any water that has been adversely affected in quality
by anthropogenic influence (an effect resulting from
human activity)
 It comprises liquid waste discharged from
 domestic residences
 commercial properties,
 industry,
 agriculture run off and encompass a wide range of
potential contaminants and concentrations.

4. SEWAGE
 Sewage is the term used for wastewater that often
contains faeces, urine and laundry waste, but offen
used to mean any waste water.
 "Sewage includes domestic, municipal, or industrial
liquid waste products disposed of, usually via a pipe or
sewer or similar structure,

5. Types of water pollution

6. Composition of waste water
Principle
Oxidizable
Material
CO2+H2O
+
Oxidized
in organics
Sulphides(S-2)
Nitrites(NO2-1)
Sulphate(SO4-2)
Nitrate(NO3-1)
bacteria
Nutrients Oxygen

7. Guidelines for sampling, Storage and
Preservation
 Collect sample from a point in waste water stream that
is representative of whole stream composition.
 All Automated and manual sampling devices ,
equipments and their tubing should be clean and free
from contamination.
 Washing with hot water, phosphate free detergent
washing, cold water rinsing and finally multiple
rinsing with the actual waste water being sampled.

8. Types of samples
 Grab sample: represent the wastewater stream at a
given point in time .
 Collected by dipping an appropriate container, bucket,
bottle or vial, into the wastewater stream using an
appropriate retrieval device, such as a chain or pole.
 Composite samples: composite sample consists of
grab samples typically taken at equally spaced time
intervals and combined (composited) once all sub-
samples have been collected.
 Flow Proportional: (Auto 1)
 Sample collection proportional to waste water stream
flow at time intervals of 30 minutes.

9. Types of samples
 MANUAL 1: A minimum of 8 grab samples taken at
equally spaced time intervals over the sampling period (e.g.
every 3 hours in a 24 hour period) combined in
proportion to the wastewater stream flow.
 Equal Time/Equal Volume:
 AUTO 2: Automatic equipment collecting samples of
equal volume at equally spaced time intervals of 15 minutes
or less over the sampling period.
 MANUAL 2: A minimum of 8 grab samples taken at
equally spaced time intervals over the sampling period (e.g.
every 3 hours in a 24 hour period) combined in equal
volumes.

10. Revised National Environmental Quality
Standards (NEQS, 1999)
S.No. Parameters Existing Standards
Revised Standards
Into Land
water
Into Sewage
Water
Into Sea
1. Temperature 40oC <3oC <3oC <3oC
2. pH Value 6-10 6-9 6-9 6-9
3. BOD at 20oC 80 80 250 80
4. COD 150 150 400 400
5. TSS 150 200 400 200
6. TDS 3500 3500 3500 3500
7. Grease and
Oil
10 10 10 10
8. Phenolic
compounds
0.1 0.1 0.3 0.3
9. Chloride(Cl-1) 1000 1000 1000 SC**
10. Fluoride(F-1) 20 10 10 10

11. Revised National Environmental Quality
Standards
S.No Parameters Existing
Standards
Revised Standards
Into Land
water
Into Sewage
Water
Into Sea
11. Cyanide (CN-
1)
2 1 1 1
12 Sulphate 600 600 1000 SC**
13 Sulphides 1 1 1 1
14 Ammonia 40 40 40 40
** = The value for industry is 200 mg/l
*** = Discharge concentration at or below Sea
concentration

12. Sampling of Waste Water
 Put on gloves and goggles. To avoid contamination,
thoroughly rinse the water sampling bottle with
sample water three times.
 Hold the bottle near its base in the hand and plunging
it, neck downward, below the surface.
 Turn bottle until neck points slightly upward and
mouth is directed toward the current.
 Tap the sides of the submerged bottle to dislodge any
air bubbles clinging to the inside. Replace cap while
the bottle is still submerged.
 Retrieve bottle and examine it carefully to make sure
that no air bubbles are trapped inside.

13. Sampling of Waste Water
 Wipe off the bottle and seal it with squash or paper
tape to avoid any entrance of oxygen.
 When sampling from a boat, obtain samples from
upstream side of boat. If it is not possible to collect
samples from these situations in this way, attach a
weight to base of bottle and lower it into the water.
 Analyze immediately after sampling.
 Preservation
 In case of distant sampling store samples in Ice box or
cooler at 4oC for DO and BOD.
 For COD add H2SO4 to pH<2 and can be stored for 28
days

14. Sampling of waste water

15. Waste Water Lab

16. Waste Water Parameters
 Biochemical Oxygen Demand (BOD5)
 Chemical Oxygen Demand (COD)
 Dissolved Oxygen (DO)

17. Dissolved Oxygen
 Dissolved oxygen in water is vital for under water life.
[
Dissolved oxygen in water is vital for underwater life. It is what aquatic creatures need to breathe. Dissolved oxygen is often called DO for short.

18. Dissolved Oxygen
 The amount of dissolved (or free) oxygen present in water
or wastewater.
 Aerobic bacteria and aquatic life such as fish must have
DO to survive.
Sources of DO
 Much of the dissolved oxygen in water comes from the
atmosphere.
 After dissolving at the surface, oxygen is distributed by
current and turbulence
 Algae and rooted aquatic plants also deliver oxygen to
water through photosynthesis. The main factor
contributing to changes in dissolved oxygen levels is the
build-up of organic wastes.

19. Dissolved Oxygen
 DO consumption
 Decay of organic wastes consumes oxygen and is often
concentrated in summer, when aquatic animals
require more oxygen to support higher metabolisms.
Depletions in dissolved oxygen can cause major shifts
in the kinds of aquatic organisms found in water
bodies.
 Temperature, pressure, and salinity affect the
dissolved oxygen capacity of water.
 Aerobic wastewater treatment processes use aerobic
and facultative bacteria to break down the organic
compounds found in wastewater into more stable
products that will not harm the receiving waters.

20. Dissolved Oxygen
 If more oxygen is consumed than is produced,
dissolved oxygen levels decline and some sensitive
animals may move away, weaken, or die.
 DO depends on micro organism and available food
supply in the form of organic components.
 DO vary with temperature and altitudes; cold water
carry more dissolved oxygen than hot water and water
at higher altitudes holds less oxygen.

21. Dependence on temp
Temp oC Conc.mg/l
10 11.1
20 9.1
25 8.3
27 8.0
30 7.5

22. Importance of Dissolved Oxygen
 We need air to
 Breath
 Aquatic organisms need to respire
 For bacteria, Invertebrates, and aquatic plants
 Decomposition of organic matter

23. Analysis of DO in field and
Laboratory
 The DO can be determined by following methods
 Iodometric Titration
 DO meter and Probe
 In field DO measured by DO meter method while
in lab by both above mentioned procedures
DO meter method
Calibrate the DO meter according to manual
instruction

24. Jenway 970 DO Meter

25. Analysis of DO
 Switch the instrument on holding down the I/O key
for 1-2 seconds.
 An internal self check
 Fill probe of DO meter by 5% KCl solution with great
care to avoid air bubbles.
 The display will either power up in %DO2 or mg/l
mode depending upon previous usage.
 Calibrate the instrument according to manufacturer
manual by making zero solution of sodium sulfite.
 Select the mode required and immerse the probe in
the sample to be measured

26. Analysis of DO
 A flow rate of 15cm/min in the sample is required, to
avoid errors due to oxygen starvation at the
membrane. If the flow rate is insufficient then the
sample should be stirred (either by a gentle stirring
action with the probe or by use of a magnetic stirrer)
 The results are expressed in mg/l or % saturation.

27. Precautions
 Make sure the probe is filled with electrolyte.
 Membrane should be wrinkle free.
 Avoid air bubble while filling the probe.
 If the probe is not to be used for 24 hours,
 store with the protective sheath fitted to prevent the
electrolyte from drying out due to evaporation through
the membrane.

28. Biochemical Oxygen Demand
 Amount of Oxygen required by micro organisms to
decompose organic matter in the given sample of water at
certain temperature over specific period of time.
 1,2,5(68%) ,10(90%),20 (99%)day test requires incubation at
20 o C.
 Depend on temperature, nutrient concentrations, and the
enzymes available to indigenous microbial populations.
 5 day test describe the amount of oxygen required to
stabilize the decomposable organic matter under aerobic
conditions.
 Five days was chosen as an appropriate test period because
this is supposedly the longest time that river water takes to
travel from source to estuary in the U.K

29. Definitions
 Aerobic and anaerobic
Processes in the presence and absence of oxygen
respectively
 Seeding
Provides micro organisms to oxidise organic matter
 Carbonaceous and Nitrogenous BOD
O2 used to degrade organic contaminants and
oxidation of Inorganic constituents like sulphides
O2 used to oxidize nitrite to nitrate

30. SEED
 Municipal sewage supernatant after 1-2 hrs of
sedimentation.
 Contain 103-106 bacteria per ml
 The seed BOD must be measured at tha same time of
that seeded samples, after dilution with high quality
distilled water

31. Methods of Measurement
 There are two methods
 Dilution Method
 Manometric pressure measurement method
Dilution Method
If BOD concentration ≥ exceeds the concentration of
dissolved oxygen DO) available in an air-saturated
sample. Therefore, it is necessary to dilute the sample
before incubation to bring the oxygen demand and
supply into appropriate balance

32. Dilution Method
 Principle: The method consists of filling with sample,
to overflowing, an airtight bottle of the specified
size(300 ml).
 Incubating it at the specified temperature for 5 d.
 DO is measured initially and after incubation, and the
BOD is computed from the difference between initial
and final DO.
 BOD= D1-D2
P where D1=Initial DO
D2=Final DO
P=Portion of sample

33. Seeding.....
 Corrected BOD value of the sample
 BOD = (Do-DT )-f (Bo-BT )
P
 D = DO in diluted & seeded sample, 0 & T days
 B = DO in seed control, 0 & T days
 f = (% seed in diluted sample)/(% seed in seed
control)

34. Manometric Pressure Measurement Method

35. Parts of BOD Meter
 Amber colored bottle of 300 ml capacity
 BOD Sensor
 Plastic Gaskets
 Measuring cyllinder(100ml)
 Measuring Flasks (157ml, 428 ml)
 Magnetic stirrers
 BOD Measuring units

36. Parts of BOD units

37. Reagents
 45% solution of Potassium Hydroixide (KOH)
 Allyl thio urea (AlTH) as nitrifying inhibitor
 Glucose-Glutamic Acid
 Ferric Chloride. Hexahydrate (FeCl3.6H2O)
 Magnesium Sulphate (MgSO4.7H2O)
 Phosphate Buffer
 Calcium Chloride (CaCl2)
 Dilution water
 Tablets

38. Working Principle
 Direct measurement of the oxygen consumed by micro
organisms from an air or oxygen-enriched
environment in a closed vessel under conditions of
constant temperature and agitation. Carbon dioxide
produced metabolically by the bacteria is chemically
bound by the potassium hydroxide solution contained
in the seal cup in the bottle.
 The result is a pressure drop in the system, which is
directly proportional to the BOD value and is
measured by the Lovibond BOD sensor. The BOD
level is then displayed directly in mg/l.

39. Working Principle

40. Measuring ranges and sample volumes
Measuring Range
(mg/l)
Sample(ml)
Volume
KOH Drops Allyl Thio urea
0-40 428 3 drops
0-80 360 3 drops
0-200 200 3 drops
0-400 157 3 drops
0-800 94 3 drops
0-2000 56 3 drops
0-4000 21.7 3 drops

41. Pre treatment of sample
 pH of sample should be 6.5 to 7.5 if not then
neutralize with IN HCl or NaOH.
 In case of chlorinated sample, dechlorinate an seed the
dilution water
 If the water is rich in nitrifying bacteria add Inhibitor
 When Nutrient content is too low

42. Sample preparation
 Select sample range and volume according to
contamination of sample
 Pour the measured amount in BOD bottle containing
magnetic stirrer.
 Take 3 drops of KOH in plastic gasket carefully
 Introduce drops of AlTH if required
 Tighten the bottle by screwing BOD sensor tightly to
avoid any entrance of oxygen
 Place the bottles in measuring units in incubators
 Attach these units with electric supply of incubator for
continuous stirring of sample
 Incubate at 2o0 C for 5 days

43. Inductive stirring unit setting

44. Inductive stirring unit setting
 On inductive Stirring unit (ISU) by pressing “esc”
 By pressing “Start” display will show range along with
volume.
 Different ranges can be selected by using + or –
buttons
 Select range by pressing “Enter”
 Then it will ask to incubate for 5 days then press enter
 The light will automatically move to next sensor head
 Again select range and incubate for 5 days
 After one day completion reading can be taken by
pressing Read button.
 Make sure incubation should be at 20oC

45. ISU setting......
 Then attach the cable to electric connection inside
incubator to introduce continuous stirring.
 Don't forget to start stirring by electric connection
other wise oxidation process will be failed
 Make sure incubation at 20oC deviation will effect
results.

46. Sample Incubation
 Tighten the sensor tightly
to avoid entrance of Oxygen

47. Washing
 Dont use detergent or soup to wash BOD bottles or
accessories as there residue will alter results
 Teepol detergent
 Deionised water

48. Glucose Glutamic Acid
 Preparation of dilution water:
 Measure 3-4 L of deionised water in a water can.
 Add 2 ml FeCl3.6H2O,CaCl2, MgSO4, 6 ml phosphate
buffer/L. Aerate the dilution water by aeration pump
or by shaking several times
 Dissolve 0.15 mg of Glucose and Glutamic acid per liter
of dilution water, add 3 ml seed
 Prepare Blank by adding seed in dilution water.
 Select range and incubate the Glucose-Glutamic acid
mixture at 20oC for 5 days.
 The result should be in the range 315+ 20

49. Chemical Oxygen demand
 The amount of oxygen required to oxidize the organic
and inorganic contaminants by strong chemical
oxidants and is used for monitoring for control of
discharges and for assessing treatment plant efficiency.
 Reagents
 Potassium Hydrogen Pthalate (1oo, 500 and 5000
ppm)
 COD vials (commercially available)
 (Mixture of Potassium Dichromate,
K2Cr2O7+Mercury sulphate (HgSO4) and Sulfuric
Acid (H2SO4)

50. Ranges and sample volumes
Ranges (mg/l) Sample
volume
KHP
standard
0-150 2 ml 100 ppm
0-1500 2ml 500ppm
0-15000 0.2 ml 5000 ppm

51. Lovibond COD Photometer

52. Principle of Photometry
 When specific reagents are added, the water sample
takes on a degree of coloration that is proportional to
the concentration of the parameter being measured.
The photometer measures this coloration.
 When a light beam passes through the coloured
sample, energy with a specific wavelength is absorbed
by the test substance. The photometer determines the
coloration of the sample by measuring the
transmission or absorption of light of this wavelength
(in other words, monochromatic light). The
photometer then uses a microprocessor to calculate
the required concentration and displays the result.

53. Principle of photometry

54. Parts of Lovibond photometer
 COD reactor ET 125 Sc
 COD Photometer
 COD Vials

55. Thermo reactor

56. Analysis of COD samples
 Select COD range according to contamination level
 Select three COD vials for single sample one for Blank,
standard and sample respectively
 Introduce 2ml blank, sample and standard in COD
vials
 Digest it in thermoreactor at 150oC for 2 hours
 Allow to cool for half an hour
 Calibrate COD photometer with standard and blank
 Then on photometer by pressing on∕ off button

57. COD analysis....
 Zero instrument by pressing zero
 Check standard as sample
 Measure COD of the sample
by pressing <read>button
 Results are reported in mg ∕l

58. Relationship between BOD and COD
 COD or Chemical Oxygen Demand is the total
measurement of all chemicals (organics & in-organics)
in the water / waste water;
BOD is a measure of, the amount of oxygen that
require for the bacteria to degrade the organic
components present in water / waste water.
The ratio of BOD/COD is about; COD is higher than
that of BOD; maximum of up to 4 times in medium
scale industries; but it varies based on the industrial
process and nature of the raw materials used;

59. Total Suspended Solids (TSS)
TSS stands for
total suspended solids,
and refers to waterborne
particles that exceed 2
microns in size.
Particle that is smaller
than 2 microns, is
total dissolved solid (TDS).

60. Total Suspended Solids (TSS)

61. TSS…
 Apparatus Needed
 Filter Paper
 Funnel
 Flask/Buckner Funnel
 Oven
 Weighing Balance
 Dessicator
 Graduated Cyllinder
 Dish Tongs
 Evaporating Dish

62. TSS….

63. Principle

65. TSS Procedure
1. Weighing of Clean filter paper (A)
2. Heating of Filter paper
3. Filtration of 100ml Sample
4. Drying in oven at 103-105oC.
5. Cooling in Dessicator
6. Weighing of F.p with residue (B)
7. Calculations
8. Reporting of results

66. Calculation of TSS
TSS= (A - B)____ X 1000
Vol. of sample
A= Weight of F.P with residue
B= Weight of Clean Filter paper