This document discusses the sources and effects of water pollution. It begins by introducing water pollution and its signs. The main sources of water pollution are identified as natural sources, agricultural runoff, mining, municipal waste, industrial effluents, and accidents. Specific examples are provided for each category. The effects of water pollution are then summarized in six points: physical effects due to suspended solids and temperature changes, oxidation effects that reduce dissolved oxygen, toxic chemical effects from metals and pesticides, chemical nutrient effects that alter pH, microbial effects, and radiological effects from nuclear waste. Eutrophication of lakes is also briefly explained.

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Water Pollution
Presented by:- Paras Kumar
B.Com 4th Semester

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INTRODUCTION
• Water pollution is a state of deviation from the pure condition, whereby its
normal properties and function are affected.
• Noticeable signs:-
 Odours from rivers, streams, lakes and ocean beaches.
 Oily and greasy materials floating on surface of water bodies.
 Unchecked growth of aquatic weeds in water bodies.
 Bad taste of drinking water.
 Decrease of aquatic life etc.
• Water pollution is studied under 3 sub-heads, viz., inland fresh surface water
pollution, ground water pollution, and marine water pollution.

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Sources of Water Pollution
Presented by:- Paras Kumar
B.Com 4th Semester

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Sources of water
pollution:-

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Sources of Water Pollution
The main sources of water pollution are natural, agricultural, mining,
municipal, industrial and accidental:
a) Natural pollution:-
• Aerial contaminants entering the water body due to rainfall or melting of
ice.
• Decaying of plants, animals and organic matter.
• Leachates from animal excreta.
b) Agricultural pollution:-
• Soil and silt washings from land surfaces.
• Fertilisers, insecticides, pesticides and weed killers.

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c) Mining pollution:-
• Tailings from ore washing
• Inert suspended solids
• Soluble toxic materials
• Acid drainage
d) Municipal pollution:-
• Sewage obtained from domestic premises, institutions, commercial and industrial
buildings.
e) Industrial pollution:-
• Effluents coming from various industries

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Point sources
• Those sources which can be readily identified ata
single location.
• For instance- industrial, municipal sewage,treatment
plants, combined sewer overflow, raw sewage
discharges, etc.
• This type of discharge can be controlled.
Diffused sources
• Those sources whose location cannot beeasily
identified.
• For instance- run off from agriculture lands,forestry,
mining, construction, etc.
• This cannot be easily controlled.
Sources of water pollution :-

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Effects of Water Pollution
Presented by:- Paras Kumar
B.Com 4th Semester

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Effects of Water Pollution
The adverse effects of water pollution can be studied under the following
heads:-
i. Physical effects
ii. Oxidation effects
iii. Toxic chemical effects
iv. Chemical nutrient effects
v. Micro-organism effects
vi. Radionuclide effects

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i. Physical Effects:-
• Due to suspended particle solids, cooling water from power stations and oily surface films.
• Solids may be inert material wastes or insoluble finely divided organic solids.
1. Inert materials in water slowly accumulate on vegetation foliage, and produce a deposit on river bed.
─ These may cause reduction in solar energy absorption thereby decreasing rate of photosynthesis
causing low oxygen conditions on the river bed.
─ Suspended materials may also cause turbidity .
2. Finely divided organic solids will be biodegraded and will cause reduction of the dissolved oxygen in
water.
• Cooling water from power stations can cause a rise in water temperature and brings about a
thermal pollution.
• Variations in temperature will affect the metabolic rate of physiological processes.
• Both these factors will cause oxygen deficiency in water.

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ii. Oxidation Effects:-
There are two types of oxidation namely:
a) Oxidation by action of bacteria upon organic pollutants.
b) Chemical oxidation of other pollutants.
• Both type of oxidation involves the use of dissolved oxygen.
• It will cause increase in Biological Oxygen Demand (BOD) .
• Causes deficiency of oxygen in water.
• Bacterial Oxidation-
Sulphides
• Chemical oxidation-
Ferrous salts
Sulphate
Ferric salts

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iii. Toxic chemical effects:-
• Some organic and inorganic chemical
substances are toxic to plant, animals
and humans.
• Chemical toxic substances can be
broadly classified as metals and salts,
pesticides, acids and alkalies etc.
• Pesticide pollutions produce harmful
effect over the body.
• Acids and alkalies may change the
Ph value of water .Changes in ph
value may affect physiological
processes and actions of toxins.

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iv. Radio- Nuclide Effects:-
• Solid waste(nuclear) filed in containers is dumped into sea bed.
• The corrosive action of sea water my cause leakage of radioactive waste in
water and it may pose health hazards.
• Radionuclides can enter the human body through dusts and aerosols and can
also be absorbed by plants and animals.

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v. Eutrophication of lakes:-
• The condition of excessive growth of plants in a water body is called ‘Eutrophication’.
• It is natural process of aging of water body.
• It is a result of very slow process of natural sedimentation of microscopic organisms
which takes geologic times to complete.
• The completion of the process results in the extinction of the water body.
• The process is propelled by increasing concentrations of nutrients necessary for
biological activity.
• Causes decreased D.O( dissolved oxygen), increased B.O.D, and emission of foul
gases.

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