En Ppt Evs Swp Water Pollution

7/27/2019 En Ppt Evs Swp Water Pollution

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Water Pollution


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Some of the stuff that it dissolves / suspends is good for us

Others, not so good


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Can you name 5 thingsthat dissolve in water?

Know of any 2 that can becalled pollutants thosedangerous to life ?


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If we drink polluted water, we can get sick


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Figure out some pollutants

C

T

S K

+ + _ _ _ _ _ _ _

Led Zeppelin

Black SabbathDeep Purple

Iron Maiden_ _ _ _ _ _ _ _ _ _

+ _ _ _ _ _ _ _

G H

Sounds like + _ _ _ _ _ _ _ _

Clue: toothpaste


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Figure out some pollutants

C T

S K

+ + ARSENIC

Led Zeppelin

Black SabbathDeep Purple

Iron Maiden HEAVY METAL

+ NITRATEG H

Sounds like + FLUORIDE

Clue: toothpaste


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How do we know that water is polluted?

Sometimes it stinksbut not always

Sometimes polluted water changes colour..but not always

Sometimes it tastes different ..but not always


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How do we know that water is polluted?

Water pollution can be confirmed only by testing it in a lab


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Sources of water pollution are generally grouped into

two categories

Non-point source of pollution:

Contamination gathered by water over a large area.

Point-source of pollution:

Contaminants enter a waterway at a discrete point


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Water can get polluted naturally

When water seeps into the ground, it absorbs differentsubstances depending on the type of soil and rock that itflows through.


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Water can get polluted naturally

Some of these substances (arsenic, iron, fluoride, etc.)can be harmful to our health.

Natural pollution is a non-point source of pollution


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Arsenic

Fluoride

Natural pollution can introduce chemicals that collect in our bodies.

Over time this can cause chronic problems and even life threatening diseases.

In groundwater

In groundwater


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Does Man Pollute Water?

If you had a bottle of life-preserving fluid

on which your life depended, would youpour into it all your sewage and rubbish,

along with any other poisonous chemicalsyou could find? And yet, that is exactly

what we are doing to our water supply allover the world.

This is what a young person like you has to say:


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The various ways in which man pollutes waterUntreated or inadequately treated municipal sewage

Yamuna, when it leaves Delhi, resembles a sewer full of the

citys wastes. A few hundred kms downstream is Agra, where

this sewer is the main municipal drinking water source.

YUCK!!

eutrophication

An example of Point source of pollution


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Reaches ground water bodies

Untreated sewage seeps in and contaminates groundwater aquifers

Such aquifers show a higher than acceptable level of nitrate content

The various ways in which man pollutes waterUntreated or inadequately treated municipal sewage



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The various ways in which man pollutes water

When garbage is dumped in alandfill, toxic chemicals leach intothe soil and groundwater.

Dumping garbage in surfacewater bodies


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Over 10 million people

bathe in the Ganga daily!


Washing and bathingintroduces phosphates andother chemicals into water


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Agriculture is a majorsource of groundwater

contamination.

AgricultureAn example of Non- Point source of pollution

dissolve in irrigation water or rainwater.

They contaminate surface water and groundwater with pollutants like

nitrates, phosphates, and non degradable synthetic

organic pollutants.


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The various ways in which man pollutes waterIndustry

Agro industries (sugar, food processing, pulp and paper, distilleries) their

wastes have high concentration of dissolved organic matter.

Chemical Industries If their wastes are not treated properly,

the chemicals can destroy our soil and water resources.

Petroleum refining water used in the process needs to be

separated from all the oil before releasing it into

naturebut is that done?


Minamata

disease


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The various ways in which man pollutes waterIndustry

Thermal power plants water is needed to cool the process.

The water gets hot and when its released into a larger

water body, it upsets the ecology by modifying the

delicate temperature balance.

This is called Thermal pollution



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Effluent treatment plants

Liquid wastes from an industry aretreated in effluent treatment plants.

Large industries have in-house effluent

treatment plants.

Its expensive for small industries to

have such plants of their own.

In some industrial estates, a group of

small industries have a common

effluent treatment plant.


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A RE-CAP

Water can be polluted by man

Water can be polluted naturally

Sewage in our water bodies

Garbage dumps

Washing and bathing

Pesticides and fertilizers

Industries


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Divide the class into 5 teams

Draw as many dashes as in the name of a water pollutant or a pollution cause.

Team A starts. They guess a letter. The teacher puts in the letter at the correct place, if it isthere in that name.

Else, the letter is written down on one side.

A maximum of 10 wrong guesses are allowed.

The team gets as many points as letters on the side (maximum of 10).

The team with the lowest number of points wins.

Hangman


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Eutrophication (pronounced as you-tro-fi-kay-shun)

When wastes with high organic content (such as sewage wastes) are

dumped into a water body like a lake or pond, eutrophication can occur,killing all life in the water body.

Organic wastes are rich in nutrients (nitrates and phosphates)

They stimulate excessive plant growth especially weedy species


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Eutrophication

On dying, the plants further add to the organic waste in water.

Microorganisms that decompose the organic material in water use upa lot of dissolved oxygen.

This depletes the available oxygen in the water and upsets theecological balance, since fish and other life forms perish withoutadequate oxygen.

Eventually all the oxygen is used up.


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Eutrophication

Anaerobic organisms then attack the organic wastes,

releasing gases such as methane and hydrogen sulphide.

The result is a foul smelling, waste filled body of water, quite like many of

the lakes in India.

These water bodies are also natural groundwater recharge systems

and their contamination also leads to groundwater pollution.


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Minamata disease

Industrial wastewater from the Chisso corporation

(manufacturing fertilizers and other chemicals) wasreleased into the Minamata Bay in Japan.

The waste water was rich in methyl mercury.

Mercury content in shellfish in that region increased.

People ate the shellfish and the cats ate theleftovers.


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Strange things started to happen cats had convulsions and died,crows fell from the sky, dead fish floated.

Young children had convulsions and difficulty in

walking and speaking.

People died.

Investigation showed organic mercury poisoning affecting the

nervous system.

First discovered in 1956.

Lawsuits and claims continue till today.

En Ppt Evs Swp Water Pollution

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