Class12th_ENVIRONMENTALISSUES

7/23/2019 Class12th_ENVIRONMENTALISSUES

http://slidepdf.com/reader/full/class12thenvironmentalissues 1/27

Environmental Issues



POLLUTION

http://schools.aglasem.com

Any undesirable change in physical, chemical or

biological characteristics of air, land, water or soil.

3 types of pollution- air, water and soil.



POLLUTANT


Pollutant- agents that bring about such an

undesirable change in air, water and soil.

Types of pollutant- (i) biodegradable (ii)

nonbiodegradable.



CAUSES OF AIR POLLUTION


Smokestacks of thermal power plants, smelters and

other industries.

Burning of fossil fuels.

Smoke from forest fires, volcanic eruption.

Decomposition of garbage.



CONTROL METHODS OF AIR POLLUTION


Electrostatic precipitator

Scrubber

Catalytic converters

Control of vehicular air pollution

Auto fuel policy



ELECTROSTATIC PRECIPITATOR




ELECTROSTATIC PRECIPITATOR




SCRUBBER




WATER POLLUTION

Pollutant

Domestic sewage Agricultural

run offIndustrial wastes




DOMESTIC SEWAGE

Domestic sewage

Suspended solids

e.g. sand ,silt,

clay

Colloidal materialse.g. fecal matter,

Bacteria, paper fibers,

Cloth fibers

Dissolved materials

e.g. nitrates,

ammonium salt,

Calcium salt,

Sodium salt




AGRICULTURAL RUN OFF

Agricultural

run off

Fertilizer

residues

Pesticide

residues




INDUSTRIAL WASTES

Industrial wastes

Chemical Physical

Organic Inorganic

Thermal (hot)

Water

Waste

Oil spills




EFFECTS OF WATER POLLUTION ON LIVING

ORGANISMS


Due to dome to domestic sewage

Due to industrial chemical wastes

Due to thermal waste water



EFFECTS DUE TO DOMESTIC SEWAGE


Consumption of dissolved oxygen due to

decomposition of sewage cause the death of

aquatic organisms.

Nitrogen and phosphorous cause excessive growthof algae and aquatic plants which in turn

Causes (i) deterioration in water quality, (ii) fish

mortality, (iii) cause diseases like typhoid, jaundice

and dysentery due to the presence of pathogens.



EFFECTS DUE TO INDUSTRIAL CHEMICAL

WASTE


Mercury and DDT cause biological magnification

High concentration of DDT disturb the calcium

metabolism, causes thinning of egg shell and their

premature breaking leading to decline of birdpopulation.

Toxic chemicals harmful to man and other animals.



BIOMAGNIFICATIONS




BIOMAGNIFICATIONS




BIOMAGNIFICATIONS OF PESTICIDE (DDT)




EFFECTS DUE TO THERMAL WASTE WATER

(HOT WATER)


Reduces or eliminates many organisms sensitive to

high temperature.

Enhance the growth of plants and fish in cold areas.



SOLID WASTES


Municipal solid waste

Fly ash

Defunct ships

Hospital wastes

Industrial wastes

Electronic wastes (e wastes)



DISPOSAL OF SOLID WASTES


Burnt to reduce volume

Buried as landfills

Incinerated

Recycled



CONTRIBUTION OF GREENHOUSE GASES TO

GLOBAL WARMING




MEASURE TO CONTROL GLOBAL

WARMING


Reduction of use of fossil fuel

Improving energy efficiency

Reducing deforestation

Planting more trees

Reduction of the use of nitrogenous fertilizer.



EFFECTS OF OZONE DEPLETION


Damages DNA due to mutation

Ageing of skin

Damages skin and cause skin cancer

Inflammation of cornea and cataract

Lethal to microbes



CAUSES FOR DEFORESTATION


Converted into agricultural land

Cleared for making homes and establishing industries

For timber and firewood

Jhum cultivation



EFFECT OF DEFORESTATION


Increase of carbon dioxide concentration

Loss of biodiversity due to habitat destruction

Disturb hydrological cycle

Soil erosion which leads to desertification.



PRESENTATION BROUGHT TO YOU BY:


http://schools.aglasem.com/

Documents

Class12th_ENVIRONMENTALISSUES