Effects of Impurities of water, Tests for water quality determination, IS 10500, 2012 (Second edition)

1. titleof
goeshereMr. M. H. Mota
Assistant professor
SITCOE
Characteristics of water
& it’s significance

2. Outcome of the session…….
To understand significance of various
quality parameters of water

3. Water…
 Water is an important natural resource.
 Globally we are facing the problem of availability of
fresh water for use.
 Water is a great solvent.
 During its pass through water picks up impurities and
gases from atmosphere in varying amounts
 Interact and dissolve inorganic and organic salts from
top soil and geological strata

4. Adverse Effects of Impurities…
Problems
 Aesthetically not acceptable and Palatability decreases
 Health related problems
 Affect mucous membrane
 gastro-intestinal irritation
 Dental and skeletal fluorosis
 Encrustation in water supply structure
 Adverse effects on domestic use

5.  Eutrofication of the waterbody .
 Taste, discolouration and corrosion of pipes fittings and
utensils
 Promotes iron bacteria
 Corrosion in water supply system
 Carcinogenic effect
 Toxic effect
 Formation of chlorophenols with chlorine
 Imparts unpleasant taste and odour after chlorination
 Water-borne diseases
Adverse Effects of Impurities…

6.  Irrigation
 pH
 Conductivity
 Sodium & Potassium
 Nutrients
 Specific compounds
 Industries
 As per specific requirement
 Domestic Consumption
As per BIS Standards (IS 10500, 2012, Second Revision )
 Water Bodies
 As per CPCB guidelines

7. Tests for water quality determination…
 Physical tests indicate properties detectable by the
senses.
 Chemical tests determine the amounts of mineral and
organic substances that affect water quality.
 Bacteriological tests show the presence of bacteria,
characteristic of faecal pollution.

8. Physical indicators…
 Water temperature
 Odour of water
 Color of water
 Taste of water

9. Physical tests…
• Temperature …… It is associated with origin of source and
ambient climatic conditions. Cool water is always
acceptable . Water temperature in the range of 10-15oC is
most desirable.
• Colour…… Colour in water may be caused by the presence
of minerals such as iron and manganese or by substances of
vegetable origin such as algae and weeds. It is measured in
terms of ‘Hazen units’. Acceptable limit is 5 Hazen units.

10. Physical tests…
• Odour and taste are associated with the presence of living
microscopic organisms; or decaying organic matter including
weeds, algae; or industrial wastes containing ammonia, phenols,
halogens, hydrocarbons. This taste is imparted to fish, rendering
them unpalatable.
While chlorination dilutes odour and taste caused by some
contaminants, it generates a foul odour itself when added to
waters polluted with detergents, algae and some other wastes.
Odour and taste should be ‘Agreeable’.

11.  pH
 Dissolved oxygen (DO)
 Total hardness
 Turbidity
 Total dissolved solids (TDS)
 Chlorides
 Heavy metals
 Nitrate
 Surfactants
 Biochemical oxygen demand (BOD)
 Chemical oxygen demand (COD)
Chemical tests…

12. pH
It is a measure of hydrogen ion concentration. It is an
indicator of relative acidity or alkalinity of water. Values
of 9.5 and above indicate high alkalinity while values of 3
and below indicate very high acidity.
Low pH values help in effective chlorination but cause
problems with corrosion.
Values below 4 generally do not support living organisms
in the marine environment. Drinking water should have a
pH between 6.5 and 8.5.
Chemical tests…

13. Alkalinity……
Alkalinity is an important parameter in water and waste water
treatment in process of coagulation.
It is equally useful in calculation lime and soda ash
requirement in water softening process.
It is useful in corrosion control process. Hence it is very
important in boiler feed water for internal conditioning.
Acidity……
CO2 determination is very important in public water supply to
reduce the corrosive characteristic resulting from CO2.
In the treatment of industrial waste which contain large
amount of mineral acid.
Chemical tests…

14.  Dissolved oxygen (DO)……
DO adds freshness to the water.
It is most important parameter in the survival of aquatic
life.
Minimum 4 mg/lit is essential.
 Turbidity……
It is mainly because of the presence of solids present in
water.
It acts as a shelter for bacteria and affects the paletability
of water.
Chemical tests…

15.  Total hardness……
 Hardness is mainly due to the presence of metallic ions (Mg/Ca)
 More quantity of soap consumed for washing clothes, this is due to
reason that 25mg additional soap is require for 1ppm of hardness of
water.
 The fabrics of cloths get spoiled washing into remove ppt. formed
by soap in hard water
 In industrial hard water from scales in the boiler due to which
more fuel is required and boiling metal over heating causing
danger to boiling point.
 Hard water can chock the pumping due to precipitation of soap in
them.
Chemical tests…

16. Chloride……
• Chloride is used as indication of population of water.
• Chloride gain excess to water either because of excellent solvent
properties on through human waste or industrial pollution.
• Chloride interference in determination of C.O.D. test if chlorides
presents in the sample.
• Chloride above 250mg/lit gives a salty taste to water which is
objectionable. So the limit is 250mg/lit for public water supply.
• The chloride content of waters used for irrigation of agriculture
crops is generally controlled along with the total salinity of water
Chemical tests…

17. Total dissolved solids (TDS)
Dissolved solid are one of the water quality parameter. the permissible
limit for potable water 500mg/lit
Quality of distilled water can be checked by measuring its conductivity or
TDS.
 Heavy metals
 Heavy metals can damage and alter the functioning of organs such as
the brain, kidney, lungs, liver, and blood. Heavy metal toxicity can
either be acute or chronic effects.
Chemical tests…

18. Nitrate…
Nitrites in the blood cause changes in hemoglobin, or the
molecules that help move oxygen in the body.
Pesticides…
Pesticides can cause short-term adverse health effects, called
acute effects, as well as chronic adverse effects that can occur
months or years after exposure. Examples of acute health
effects include stinging eyes, rashes, blisters, blindness, nausea,
dizziness, diarrhea and death.
Surfactants…
 Prolonged exposure to surfactants can irritate and damage the
skin because surfactants disrupt the lipid membrane that protects
skin and other cells.
Chemical tests…

19. • Turbidity……
Aesthetics- The consumers are not accepting the turbid water due to bad
appearance.
Filterability – If the water has high turbidity value during filtration. it will
be filtered repeatedly will require frequent removal of media and back
washing which obviously attack the efficiency of filter and increase the
cast of filtration.
Disinfection – during disinfection process the suspended particle from a
shelter for the bacteria and protect it from direct attack of disinfection
and required more quantity of disinfection agent.
Efficiency of treatment unit – due to turbidity, efficiency of turbidity is
considerable reduced which increase the cost of maintenance of
treatment plant.
Chemical tests…

20. Biochemical oxygen demand (BOD)
It denotes the amount of oxygen needed by micro-
organisms for stabilization of decomposable organic
matter under aerobic conditions. High B.O.D. means that
there is less of oxygen to support life and indicates
organic pollution.
Chemical oxygen demand (COD)
It is a measurement of the oxygen required to oxidize
soluble and particulate organic matter in water.
Chemical tests…

22. IS 10500, 2012 (Second edition)

23. IS 10500, 2012 (Second edition)

24. Lets meet in next session to
know more….