PREPARED BY
Mr. PRASANNA
DCE, BE, M.TECH
Water Pollution
• The contamination of water by
addition of toxic pollutants which are
harmful to living organisms is called
water pollution.
OR
• Water pollution is defined as the
presence of solid, liquid or gaseous
contaminants that may alter the
quality of water and water become
unfit for its desired use then it is
considered as polluted water.
Point sources of Water Pollution
Pollutant enters the water
then such sources of
pollution are identified as
point sources of pollution.
Industrial discharge pipes
Point sources of Water Pollution
Municipal sewage
Point sources of Water Pollution
Waste water/sewage water
treatment plants
Sources of water pollution
1. Domestic sewage
The sewage contains human
faeces, urine, kitchen wastes,
street wastes and organic
substances.
The undesirable effects include
spreading of water borne
diseases.
Sources of water pollution
2. Natural water Pollution
Contaminants entering water via
rainfall, storm, ice melting. Also
decaying of plants, dead animals
and organic leachates from animal
excreta will introduce
microorganisms in water
Sources of water pollution
3. Agriculture Pollution of water. • Land slide at Jodupal Madikeri
Soil washings from land
surfaces, fertilisers, insecticides,
pesticides or weedicide.
Sources of water pollution
4. Mining Pollution of water . It
occurs due to ore washing acid
drainage, inert suspended solids
and soluble toxic materials.
Sources of water pollution
5 . Industrial Pollution of water.
It occurs due to effluents coming
from industrial activities food
processing, drugs and chemicals.
Sources of water pollution
4. Mining Pollution of water . It
occurs due to ore washing acid
drainage, inert suspended solids
and soluble toxic materials.
Sources of water pollution
6 . Municipal Pollution of water.
Municipal Pollution of water. It
occurs due to sewage coming
from homes, bathrooms,
apartments, hospitals, commercial
and industrial buildings.
Sources of water pollution
7. Pollution of water due to
accidental events. It occurs due
to leakage, spillage and run offs
of chemicals/ oils/petrol/diesels/
acids during loading and
unloading, transit at tanker/
trucks/lorries on the road sides.
Sources of water pollution
8. Thermal and radioactive waste.
Different Industries and nuclear
power plants use water and
discharge the heated water into
nearby water bodies. Nuclear
reactors, nuclear explosions,
medicinal use and research
laboratories are main source of
radioactive waste.
Sources of water pollution
9. Bio degradable and non bio
gradable. Consists of organic
waste from domestic sewage.
They are decomposed by micro
organisms naturally or can be
artificially decomposed in
chemical treatment plants.
Types of Water Pollutants
Oxygen demanding waste -
Example. Human, animal waste, decaying vegetation
Disease causing wastes -
Example. Bacteria and viruses
Synthetic organic compounds -
Example. Detergents, oil, Insecticides
Inorganic chemicals and mineral substances
Example: Hg, Cd2+, Pb2+ etc.
Types of Water Pollutants
Plant nutrients.
Example. Nitrates, Phosphates.
Sediments and suspended solids
Example. Slit from land erosion
Radio active substances/wastes
Thermal discharge
Example. Water used for cooling in industry
Oil from oil spills and washing of automobiles pollutes river and
lakes.
Characteristics of water pollutants
1. Water pollutants changes the colour of water.
2. They change the taste and odour of water.
3. They affect the pH value of water
4. They cause normal water to become hard and poisonous
5. They cause the turbidity in water
6. They increase the temperature of water
Natural or unpolluted water is colourless, odourless and
transparent
Control measures of water pollution
There are many methods to control water pollution –
The sources of potable water must be away from the industries.
This is to avoid seepage of toxic industrial effluents.
The industries should be given training and facilities to treat
their sewage before discharging it.
Safe disposal of sewage water is done effectively by installing
the sewage water treatment plants, septic tank etc,
Reducing the use of pesticides, insecticides and chemical
fertilisers. This will prevent runoffs of the material into nearby
water sources.
Control measures of water pollution
Waste waters should be properly treated by primary and
secondary treatments to reduce the BOD (Biological Oxygen Demand)
and COD (Chemical Oxygen Demand) up to the permissible level for
discharge.
Proper chlorination should be done to prevent the formation of
chlorinated hydrocarbons or disinfections should be done by ozone
or ultraviolet radiations.
Proper planning of towns for its development
Water (Prevention and control of pollution) act 1974
The Water (Prevention & Control of Pollution) Act, 1974 was
adopted by the Indian parliament with the aim of prevention and
control of Water Pollution in India.
Under Water Act 1974, Sewage or pollutants cannot be
discharged into water bodies including lakes and it is the duty of the
state pollution control board to intervene and stop such activity.
Anyone failing to abide by the laws of under is liable for
imprisonment under Section 24 & Section 43 ranging from not less
than one year and six months to six years along with monetary fines
