Sources and effects of water pollution , major pollutants of water pollution.

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Water Pollution
Presented by:- Group 3

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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:- Cris George Sam

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Section Title 2
Subtitle
4
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 Diffused sources
• Those sources which can be readily identified at a
single location.
• For instance- industrial, municipal sewage ,treatment
plants, combined sewer overflow, raw sewage
discharges, etc.
• This type of discharge can be controlled.
• Those sources whose location cannot be easily
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:- Ebin Jacob Anish

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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.

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• 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.
• Increased temperature will cause decrease in fresh water fauna population
and increase in flora population.
• At higher temperatures blue green algae and sewage fungus will grow
more which will result in plant death.
• The oxygen saturation percentage will be reduced and biodegradation will
be increased.
• Both these factors will cause oxygen deficiency in water.

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• Waste oil, fats and grease can enter from several sources.
• These will form a thin film on the water surface which prevents the
exchange of oxygen with the atmosphere causing reduction of water
oxygen saturation.
• Spillage from oil tankers in sea will cause marine pollution and shore
contamination.
• Oil slicks are responsible for the death of many birds.
• Oil reduces the thermal insulation and resistance to cold, irritates digestive
system and produces toxic effects.
• A badly oiled shore can be largely denuded of animal life and sea weeds
are also affected.

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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 Sulphate
• Chemical oxidation-
Ferrous salts 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. Chemical Nutrient Effects:-
• Chemical nutrients are required by plants and animals for maintaining their growth and
metabolism.
• Nitrates and phosphates occur in water in small quantities.
• The nutrient levels slowly rise as a result of bio-degradation of dead organic material.
This rise in nutrients is called ageing or eutrophication.
• Increased concentration of nitrates and phosphates in water produce the overall effects
of an increase in the rate of growth of plants and animals.
Unicellular green and blue green algae and blanket weed reduce light
penetration and restrict reoxygenation of water.
• It will cause adverse conditions for river and canal navigation, and for swimming,
bathing and fishing.
• Nitrates are taken into body by food and drink and excess will cause blood diseases
and gastric cancer.

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v. Micro- organism Effects:-
• Wastes that are discharged into water
contain pathogenic organisms that are
capable of transmitting human diseases.
• Bacteria are responsible for cholera,
typhoid fever, bacillary dysentery,
gastroenteritis.
• Virus may cause poliomyelitis, infective
hepatitis, and echo and consackil fevers.
• Round worm beef and pork tape worms
may also cause diseases.

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vi. 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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vii. 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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Major Pollutants of Water
Presented by:- Greshma T John

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Classification of Water Pollutant
• The various types of water pollutants can be broadly classified in to four
categories.
1. Organic pollutant
2. Inorganic pollutant
3. Radioactive pollutant
4. Suspended solids and sediments

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Organic Pollutant
The organic compounds may further be categorised as follows
• Natural organic pollutant
• Sewage and industrial effluents
• Synthetic organic contaminants
• Microbiological components

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Natural Organic Pollutant
• Natural organic contaminants in water come from the breakdown of
naturally occurring organic materials like decay of leaves, plants ,dead
animals etc.
• Many plants and micro organisms release organic matter in to a water
body through their metabolic processes.
• Various types of algae and vegetation flourishing in a lake or reservoir can
also be a source of objectionable organic compounds in water.

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Sewage and Industrial Effluents
• Organic pollutants are also discharged as municipal sewage and industrial
effluents (such as food processing units,paper ills,etc .)

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Synthetic Organic Components
• These are man made materials which may enter the water bodies along
with sewage and other wastes.
• Synthetic organic components includes both volatile organic chemicals and
synthetic organic chemicals.
• Most common organic pollutant in VOC are industrial solvents , such as
carbon tetrachloride(used as fire extinguisher and cleaning agent).
• Most common organic pollutant in SOC are pesticides and herbicides.
• Presently , the most controversial organic pollutant are polychlorinated
biphenyls and dioxin, which are very toxic and known to cause caner even
at very low concentration.

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Micro-biological Pollutants
• Many different micro organisms such protozoa ,viruses , bacteria are found
in polluted water.
• Most of these do not pose a health hazard to humans.
• The organisms that can cause sickness In human are called pathogenic
organisms.

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Inorganic Pollutant
• Apart from the organic matter discharged in the water body through
sewage and industrial wastes high concentration of heavy metals and other
inorganic pollutants contaminates the water.
• The accumulation of heavy metals may have adverse effect on aquatic
flora and fauna and may constitute a public health problem where
contaminated organisms ae used for food.
• Algal growth due to nitrogen and phosphorous compounds can be
observed . Metals in high concentration can be toxic to biota.

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Radioactive Pollutant
• Radioactive materials orginates from the following:
• Mining and processing of ores.
• Use in research ,agriculture ,medical , and industrial activities such as I131
,P32 ,CO60 , Ca45 ,S35 , ETC.
• Radioactive discharge from nuclear power plants and nuclear reactors.
• Uses and testing of nuclear weapons.
• These isotopes are toxic to lifeforms ,they accumulate in the bones and
can cause serious disorders.

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Suspended Solids And Sediments
• Comprises of silt ,sand , and minerals eroded from land.
• Appears in the water through surface runoff during rainy season and
through municipal sewers.
• This can lead to the siltation , reduces storage capacities of reservoirs.
• Deposition of solids in the quiescent stretches of the stream and ocean
bottom can affect normal aquatic life and affect the diversity of aquatic
ecosystem.

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Common Water-Borne Diseases
Presented by:- Fathima D

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Water-borne diseases are caused by pathogenic organisms carried by water
containing faecal or sewage contamination.
a) Bacterial Diseases
1. Typhoid fever:-
• Typhoid fever is the most important endemic and epidemic water borne disease of
regions where supplies are drawn from surface sources contaminated by human
faeces or urine.
• This is caused by the bacterium salmonella typhi.

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2. Paratyphoid fever:-
• Mostly due to ingestion of contaminated food, specially milk, dried or frozen eggs and
other diary products.
• This is caused by bacterium Salmonella paratphi A, B or C.
• Number and infectivity of organisms released to environment are generally smaller
than the typhoid fever.
3. Cholera:-
• This is caused by the bacterium vibrio cholerae.
• Usually the infection is contracted by ingestion of water contaminated by infected
human faecal material.
• Sometimes it may be contracted by contaminated food or personal contact.
• Cholera is much more violent in its onset and often more fulminating in its clinical
course.

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4. Bacillary dysentery:-
• This is caused b bacteria of genus shigella, Sh. Dysentrial, Sh. Flexneri, Sh. Boydii and
Sh. Sonnei.
• This disease is mostly contracted due to ingestion of food contaminated by flies or by
unhygienic food handlers.
• It may sometimes be contracted by consuming water contaminated by human faeces.
b) Protozoal Diseases:-
• The 2 important diseases that come under this category are: Amoebiasis and amoebic
dysentery.
• These are caused by the protozoon entamoeba histolytica.
• They live in the human large intestine forming cyst which are excreted in the bowel
discharges of infected persons and which will live for long periods in water.
• Infection takes place due to ingestion of these cysts which are carried by water or flies or
even human fingers.

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c) Virus Diseases:-
• The recognized viruses that are of serious concern are the following members of the
enteric virus group: polio viruses, coxsakie viruses , ECHO viruses, the viruses of
infectious hepatitis, the adenoviruses and the reoviruses.
• The poliovirus persists in the intestines of infected persons for a short time after infection
which probably takes place from contaminated fingers directly or on food.
• Poliomyelitis is common where sanitation and food hygiene are poor.
d) Helminthic (worm) disease:-
• Worm infections are sporadic and occur only under grossly insanitary conditions or
through gross mismanagement of sewage disposal system.
• The common diseases that are spread are schistosomiasis and swimmer’s itch.
• The causes of schistosomiasis is a group of trematode worms that inhibit the viens of
bladder or large intestines and discharge eggs into the urine.

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