This ppt will give you all about water pollution and its major causes of contamination

1. Prepared by,
MABIN PAULSON

2. What is pollution?
Pollution is the
contamination of
the natural
environment with
harmful substances
often as a
consequence of
human activities.

3. WATER POLLUTION is an undesirable change in
the state of water, contaminated with harmful
substances. It is the second most important
environmental issue next to air pollution.

4. MAJOR SOURCES OF CONTAMINATION
Industrial wastes
Domestic wastes

5. NOTABLE SIGNS OF WATER POLLUTION
Bad smell.
Offensive odour.
Uncontrolled growth of weeds.
Decrease in number of aquatic life.
Oil and grease floating on the surface
of water.

6. MAJOR WATER POLLUTANTS
Domestic sewage
Organic pollutants
Industrial effluents
Soap and detergents
Agricultural discharges
Pesticide pollution
Fertilizer pollution
Bacterial pollution
Oil pollution
Heavy metals
Eutrophication

7.  DOMESTIC SEWAGE
 Huge quantities of municipal and domestic wastes released
through drains into canals and rivers become the major
cause behind the water pollution.
 Domestic sewage contians kitchen wastes,human
excreta,urine and other organic wastes.

8. Major problems caused by domestic
sewages
 It produces foul smell.
 Spreads diseases like cholera,typhoid,malaria,etc.
 Leads to oxygen depleation in water.
 It encourages eutrophication.

9.  ORGANIC POLLUTANTS
 Organic substances are the substances which serve as
food for living organisms to obtain their energy needs
and to build new cells.
 eg;-sulphur,iron ,proteins,fats,oils ,urea,etc.

10. •It decreases the oxygen available in the water and destroy aquatic
life.
Aerobic respiration Anaerobic respiration
The decomposition of organic matter
carried out under oxic conditions.
The decomposition of organic matter
occur in absence of air.
It produces simple and stable end
products like CO2,H2O,NH3 etc.
It produces unstable compounds like
alcohols,acids,ketones,methane etc.

11.  INDUSTRAL EFFLUENTS
 Industry is a huge source of water pollution, it produces
pollutants that are extremely harmful to people and the
environment. Many industrial facilities use freshwater to
carry away waste from the plant and into rivers, lakes and
oceans.
 A major cause of industrial water pollution due to
discharge of waste water
containing high pollutant
concentrations.

12.  Industrail wastes includes several objectionable materials
like
acids,alkalis,detergents,phenols,soaps,cyanides,lead,zinc,
copper,mercury,pesticides,insecticides,fungicides etc.It
depends on the kind of industry.
 Eg:-Wastes of fertilizer industries are found rich in organic
matter.

13.  SOAPS AND DETERGENTS
 Soaps are derived from fats and oils by saponification
with sodium hydroxide.
 Soaps when hydrolyzed with water,the resulting fatty
acids increase the organic content of the water which
in turns leads to the depletion of dissolved oxygen.
 Soaps and detergents reduces aeration of water due to
the production of foams.
 They had the disadvantage of
getting precipitated in the presence
of dissolved oxygen.

14. Some detergents are found directly toxic to several
organisms since they impair the selective permeability
of cell membranes.
Phosphate containing detergents cause eutrophication
in water.
Detergents can also damage the external sensory
organs of many organisms affecting their food search
and capturing capacity.

15.  AGRICULTURE DISCHARGES
 Agricultural discharges refers to biotic and abiotic byproducts
of farming practices that result in contamination or
degradation of the environment and surrounding ecosystems,
and/or cause injury to humans and their economic interests.
 Nitrogen compounds are produced by the use of nitrogen
fertilizer and these compounds take part in water pollution.
Herbicides, germicides and insecticides are widely used or
spray on crops. These compounds increase the water
pollution.
 Modern agricultural practices make use of several chemicals
called agrochemicals in the form of
fertilizers,pesticides,growth hormones etc.

16.  PESTICIDE POLLUTION
o Pesticides are substances used to prevent,destoy or
control objectionable insects,rodents,plants,weeds or
other undesirable forms of life.

17. Problems caused by pesticide pollution
It percolates into the ground water and make ground
water poisonous.
They tends to concentrate in aquatic plants and
animals to higher values of several thousand times.
Since they are persistent in nature , they persist in soil
for thousands of years.
Biomagnification :-a phenomenon in which
theconcentration of a chemical increases at higher
levels in the food chain.

18.  FERTILIZER POLLUTION
 Excessive use of fertilizers make agricultural run-off in
nutrients, which results in algal blooms.
 Their decomposition reduces oxygen level in the water
which cannot support normal life forms.
 Algea and organic matter add colour ,foul
smell,turbidity to the water which are difficult to
remove.
 It also supports eutrophication.

19. Algal bloom

20.  BACTERIAL POLLUTION
 Dead bodies of man,wild and domestic animals,birds
etc.decaying in water bodies can cause heavy
degradation of the quantity of water through bacterial
pollution.
 They causes infections like
cholera,typhoid,polio,dysentery etc.
 Water contaminated with sewage may contain various
pathogenic organisms belonging to
bacteria,viruses,protozoa etc.

21. Diseases caused by pathogenic organisms

22.  OIL POLLUTION
 Oil based technology increased nowadays thus,
increasing oil pollution.
 Oil pollution is undesirable because it reduces light
transmission through water and hence,
photosynthesis by marine plants.
 It also decreases the dissolved oxygen in water.
 Birds are particularly affected by oil pollution.
 Aquatic organisms are badly affected by oil pollution.

23. Effects of oil on aquatic organisms are:-
a. Direct lethal toxicity.
b. Disruption of physiological or behavioral activities
and
c. Changes in biological habitats.

24.  HEAVY MEATLS
 Heavy metals includes
zinc,copper,cadmium,mercury,lead,iron etc.
 When metals get into the water bodies they are
harmful to the aquatic life and others who are drinking
it.
 Effluents from industrial processes like metal
extraction,metal plating,chemical manufactures
etc.also contribute to heavy metal pollution.

25. SOURCES AND TOXIC RESPONSES OF METALS
METAL SOURCES AND TOXIC RESPONCES
LEAD{pb} It is highly toxic.It cause brain and kidney damage.In
youngsters,it causes mental retardation and convulsions in later
life.
MERCURY{Hg} It is used in amalgams,batteries etc.Mercury is inert and nontoxic
in elemental form.Mercury vapour is highly toxic when inhaled.
CANDMIUM{Cd} It is used in paints,batteries and plastics.
At extreme levels it causes the illness “Itai-Itai” characterised by
brittle bones and intense pain.It also causes kidney damage,high
blood pressure etc.
CHROMIUM{Cr} It is used in industry to make alloys,catalysts etc.Cr has two
oxidation state and Cr(VI) causes skin disoders and liver
damages.
COPPER{Cu} It is a gastrointestinal tract irritant.In some people copper
metabolism disoders called wilson’s diseases are found.

26. SOURCES AND TOXIC RESPONSES OF METALS
NONMETAL SOURCES AND TOXIC RESPONCES
ARSENIC{As} Ar gains access to the water environment through mining
operations etc.Skin cancer,hyper-pigmentation etc.are the
health problems associated with Ar rich water intake.
CYANIDE Cyanides gains access to the water environment through the
discharge of rinse water from plating operations and coal
coking waste water.It can serve as a source of energy for
aerobic bacteria.

27.  EUTROPHICATION
 The process of increase in the nutrients of water and
the resultant spurt in algal productivity is called
eutrophication.

29. DISEASES CAUSED BY WATER POLLUTION

30. METHODS TO CONTROL WATER
POLLUTION
1)Reduction of waste water source by trapping
nutrients,proper aeration etc.
2)Recycling of waste water.
3)Waste water reclamation.
4)Proper dilution of waste water before their
discharge into waterbodies.

32. WATER TREATMENT PLANTS

33. What We Can Do

34. Turn off running water

35. Spread awareness

36. Participate in a clean up

37. Join a special society devoted to the
prevention of water pollution

38. CONCLUTION
 It is hard to imagine that one person can make a difference
in protecting and conserving fresh water supplies on this
planet, but each individual can really help the
environment.
 Water pollution is very serious problem and it can be
controlled by providing proper escape to sewage and
industrial waste water.
 Also contaminated water can
be treated and reused so as to
reduce water pollution.

42. Reference:-
www.google.com
www.slideshare.net
Modern Engineering Chemistry-
Dr.kochu baby manjooran S.