GREEN GREETINGS…
ENVIRONMENTAL STUDIES
UNIT V
AIR POLLUTION
WATER POLLUTION
SOIL POLLUTION
Introduction
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POLLUTANT : Any physical, chemical or biological agent that in its
sheer presence has impact on environment that makes a particular
resource useless for its designated use.
POLLUTION is a situation where pollutants bring undesirable
changes in the environment.
SOURCES of pollutant :
Natural sources
Anthropogenic/ Man made sources
EFFECTS
CONTROL MEASURES
AIR POLLUTION
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AIR POLLUTION : Air Pollution may be broadly be defined as the
presence of one or more contaminants like dust, smoke, mist, odor in
the atmosphere which are injurious to human beings, plants and
animals or which unreasonably obstruct life and property.
Air Pollution may be described as “ The imbalance in quality of air so
as to cause adverse effects on the living organisms on earth”.
COMPOSITION OF AIR : Atmosphere is gaseous envelope
surrounding the earth which constitutes Major gases (N2, O2, CO2),
Minor gases (He, ) and Trace gases (SO2, CO, CH4).
Based on Temperature changes Air environment is divided into 4
segments
Troposphere (Altitude range is 0 to 11Kms)
Stratosphere (11 to 50kms)
Mesosphere (50 to 85kms)
Ionosphere (85 to 100kms)
Types of Air pollutants
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Air Pollutants are of two types, Primary and Secondary pollutants
based on the source.
Primary pollutants are directly emitted from the source. e.g., SO2, CO2
etc.,
Secondary pollutants are resulted from environmental reactions. e.g
NO3, H2SO4 etc.,
Particulates include Aerosols, Mist. Dust, Smoke, fumes, fog and
smog.
Sources of Air Pollution
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Air pollutants are substances causing damage to animals, plants, building
material which is adversely affected by pollutants.
Major Sources of Air Pollution
Natural Sources :
Volcanic eruptions – poisonous gases such as SO2, H2S, CO etc.
Forest fires - H2S, CH4 etc.
Evapo transpiration process – CO2
Oxidation process – natural photochemical reactions
Man made sources/Anthropogenic Sources include
Population explosion – emission of GHG’s result in global warming
Deforestation – imbalance of CO2 and O2 in the nature
Burning of fossil fuels – combustion process
Emission from transportation sector – Automobile exhausts result in PCS
Rapid Industrialization – Power plants, Smelters, refineries etc.
Agricultural activities – pesticides, insecticides, herbicides etc.
Effects of Air Pollution
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Pollutants are generally classified as Gaseous pollutants, Particulate
pollutants, Aerosols, Radioactive pollutants.
Gaseous pollutants – CO2, CO, SOx, NOx, Hydro carbons
Carbon dioxide
Traps heat in the atmosphere result in Global warming
Carbon monoxide
Harmful to humans, affects respiration, cardiac and pulmonary functions
SOx :Oxides of
Sulphur
Acid rains wash away nutrients, necrosis on leaves
bronchitis, emphysema and psychological disorders in humans
Effects on materials,Stone leprosy: H2SO4 corrodes on marble monuments
NOx :Oxides of
Nitrogen
Toxic produces irritating effect, affects lungs – bronchitis, emphysema.
chlorosis effects and decreased photosynthetic activity in plants.
Hydro carbons
React with NO to form secondary pollutants, Photo Chemical Smog
Particulate pollutants
(fumes, dust, smoke etc)
Toxic mist, chronic non specific diseases, soil corrosion.
Aerosols
Air pollutants remain suspended in air
Radioactive
Pollutants
Cellular damage in man and animals
Control Strategies
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Control of NOx pollution : Removal of NOx by catalytic decomposition
and Scrubbing process
Discharge of gaseous pollutants by building higher smoke stacks (vent)
Control of SOx pollution : Removal of Sulphur from fuel before burning,
and using sorption methods.
Control of CO pollution : Exhaust gas analyzers to check emissions
Vehicular pollution can be controlled by upgrading fuel quality, using
catalytic convertors.
Control of Hydro carbons : Incineration, adsorption, absorption and
condensation
Control of particulate matter : Cyclones, electrostatic precipitators, filters
etc.
Reforestation programs
WATER POLLUTION
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Water is elixir of life.
Water pollution is defined as the alteration of physical, chemical and
biological characteristics of water resulting in harmful effects on life
systems.
Characteristics of water
Types of water pollution :
Ground water pollution
Surface water pollution
Lake, River and Sea water pollution.
Sources of Water Pollution
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Major sources are divided into Natural and Man made
Natural Sources:
Eutrophication process
Floods
Man made sources:
Sewage and domestic wastes
Toxic metals
Industrial effluents
Agricultural discharges
Detergents, pesticides
Siltation process
Effects of Water Pollution
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Sewage and domestic wastes effect human health resulting diseases
such as cholera, typhoid, dysentery
Industrial discharges contain Lead, arsenic, Mercury, Cadmium etc.,
which pose deleterious impacts in life systems
Lead – damages liver and kidney
Arsenic – lung cancer, ulcers in gastro intestinal tract
Cadmium – diarrhea, kidney cysts, bone deformation etc
Mercury – Neurological disorders
Agricultural discharges include fertilizers, pesticides which are toxic to
both aquatic and human life.
Control Strategies
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Sewage treatment plants
Integrated approach and organic farming
Ideal maintenance of plant upkeep in Industries
Management and legislation – CPCB
Water treatment
Primary treatment involves coagulation and flocculation
Secondary treatment involves disinfection process
Information dissemination through sensitization programs.
SOIL POLLUTION
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Soil is the uppermost weathered layer of earth’s crust and is a
significant ecological factor in sustenance of biosphere.
SOURCES OF SOIL POLLUTION:
Natural
Erosion – wind, water
Man made
Industrial Wastes
Urban wastes
Agricultural wastes
Radioactive wastes
Mining
Effects and control of Soil Pollution
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These pollutants affect and alter the chemical and biological properties
of the soil, as a result these toxic elements enter into human food chain
from soil or water and finally pose deleterious effects on living
organisms – biomagnification process.
Control Strategies :
Check dams/ Rock filled dams
Trenches
Organic farming