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2. Types of Environmental pollution
 Main type of pollution are
 Air pollution
 Water pollution
 Marine pollution
 Soil pollution
 Noise pollution
 Thermal pollution
 Radioactive pollution

3. Air pollution
 Air pollution is the presence in ambient atmosphere of
substance generally resulting from the activity of man
in sufficient concentration present for sufficient time
& cause the harmful effect on humans, plants &
animals

4. Sources/causes of Air pollution
 Natural
 Manmade
 Natural sources of air pollution are
 Pollen grain
 Volcanic eruption
 Forest fire
 Salt spray from ocean
 Dust storm
 Marshy land
 Bacteria & other microorganism
 Spores
 Photochemical reaction

5. Sources/causes of Air pollution
 Man made sources include
 Industrial units
 Thermal power plant
 Automobile exhaust
 Fossil fuel burning
 Agricultural activities
 Mining
 Air crafts
 Nuclear explosion
 Domestic burning of wood

7. Sources/causes of Air pollution
 Man made sources can be classified in to
 Point or stationary sources : Example of point
sources is industrial unit which adds pollutant to air at
particular points from their tall chimney
 Line Source : The line or mobile sources of air
pollution are the automobile as these add pollutants
along narrow belts & over long distance
 Area Source : Town & cities add smoke & gases over
wide areas & so it is called as area sources of air
pollution.

9. Classification of Air Pollutants
 According to the origin air pollutants can be classified
in to
 Primary pollutants - They are emitted directly from
the sources and are found in the atmosphere in the
form in which they were emitted
 For example – Sulphur oxides, Nitrogen oxides,
hydrocarbon, ash, dust smoke fume etc.
 Secondary pollutants – They are formed in the
atmosphere by chemical interactions between primary
pollutants and atmospheric constituent
 For example -Sulphur trioxide, PAN, aldehyde, ketones
etc.

11. Classification of Air Pollutants
 According to the state of matter air pollutants are
classified as
 Gaseous Pollutants : These pollutants are in gaseous state
at normal temperature & pressure
 Common gas pollutants are CO, CO2, Nox, Sox
 Particulate air pollutants :
 These includes suspended droplets, solid particles or their
mixture in the atmosphere commonly referred as
particulates
 For example aerosols, dust, smoke, mist, fog, soot, fly ash,
etc

13. Air Pollutants – Sources & Effects
 CO
 CO2
 Oxide of Nitrogen
 Oxide of sulphur
 Photochemical oxidant
 Particulate matter

27. Effects of Air pollution
 Effect of Air pollution on human health
 Eye irritation can be caused by many air pollutants such as
Nox, O3, PAN, smog, particulates etc
 Nose & throat irritation can be caused by SO2, Nox,
pesticides etc.
 Gaseous pollutants like H2S, NO2, SO2, & hydrocarbon
can cause odour nuisance even at low concentration
 Irritation of respiratory tract can be caused by Sox, Nox,
O3, CO etc.
 Pollen can initiate asthma attack
 High concentration of SO2, NO2, SPM can cause
bronchitis & asthma

28. Effects of Air pollution
 CO which is two hundred times more reactive than O2,
combine with hemoglobin in blood and increase stress on
those suffering from cardiovascular & pulmonary disease
 NO can react with hemoglobin & reduce the O2 carrying
capacity of the blood.
 Hydrogen fluoride can cause florosis & mottling of teeth.
 Dust particle can cause dust specific respiratory disease
such as silicosis (associated with silica dust) and asbestosis.
(associated with asbestos dust)
 Heavy metal like lead can cause poisoning. Its high
concentration can cause damage liver & kidney

29. Effect of Air pollution on Plant

30. Effect of Air pollution on Plant
 SO2- Bleaching of leaves, necrosis (Killing of tissues)
 O3 – Premature ageing, suppressed growth, necrosis ,
bleaching, collapse of leaf
 NO2 – Suppressed growth, bleaching
 Fluorides – Necrosis at leaf tip
 PAN – Suppressed growth, silvering of lowering leaf
surface

31. Effect of Air Pollution on Property

32. Effect of Air pollution on Property/Material
 SO2 in the presence of oxygen & moisture is converted
in to H2SO4 acid. Deposition of this acid in metal part
of building roof, railway track, metal on bridge cause
corrosion
 H2SO4 acid deposition react with limestone, marble &
other building material to cause deterioration and
disfigure the material
 Pollutant like SO2, O3, H2S & aerosol damage
protective coating & paints of the surface
 O3 & PAN cause cracking of rubber tyres & various
form of electrical insulation
 Deterioration of leather & paper due to H2SO4
deposition

33.  Damage of textile fiber & textile dyes is caused by Sox,
Nox, & O2
 SPM of large size carried by wind travel at high speed
when they strike any surface deterioration take place.

34. Effect of Air pollutants on climate
 Due to deforestation & fuel combustion in industries &
automobiles the CO2 content of the atmosphere is
expected to double by the year 2020.
 The increase of CO2 will increase the atmospheric
temperature of earth resulting in this melting of ice,
glaciers etc. which will consequently cause the flooding of
coastal towns (i.e. green house effect).
 Pattern of rainfall , if changed will affect agricultural
output.
 The thinning of ozone layer in stratosphere by the action of
aerosol will increase the penetration of harmful ultraviolet
rays to earth & this will cause blindness, sunburn,
inactivation of proteins, RNA and DNA.

35. Effect of Air pollution on Aesthetic Beauty
 The aesthetic beauty of nature is not visible (reduction
in visibility results from scattering of light by air borne
particulates (0.1 to 1 micrometer size)
 This also leads to safety hazards in the haze formed by
dust & smoke in the air.
 Industries, automobiles, sewage & garbage heaps emit
foul odours causing further loss of aesthetic beauty.

36. Control of Air Pollution
 Controlling measure for air pollution can be mainly
divided in to
 Preventive measure
 Control measure i.e. Control of gaseous/particulate
pollutants from industry/ automobile using
equipment
 Preventive measure : Some of the important
preventative measures are
 (1) Selection of suitable fuel for example
 (a) Use of low sulphur coal in power plants
 Using LPG/CNG instead of diesel or petrol in
automobile

37. Control of Air Pollution
 (2) Modification in industrial process for example
 If the coal is washed before pulverization then fly ash
emission are considerable reduced
 Selection of suitable site & zoning for industrial unit
 Industrial area should be far away from residential
Zone
 By using proper environmental impact studies before
setting the industry

38. Control of Air Pollution
 Control Measure
 Where it is not possible to control the air pollution at
source some measure are to be adopted to control the
level of pollution
 The most common method of eliminating or reducing
pollutants to an acceptable level include
 Collecting the pollutants by using equipments to
prevent the escape in to atmosphere
 Destroying the pollutants by thermal or catalytic
combustion
 Changing the pollutants to a less toxic form
 By releasing the pollutants through tall chimney for
greater dispersion

39.  Control of particulate matter :
 Particulate matter can be controlled by using following
devices/equipments
 Gravitational settling chamber :

40.  Gravitational settling chamber : It is used to remove
particles with size greater than 50 micrometer.
 Velocity of the flue gas is reduced in large chamber
thereby including settling of particle of the particles
under gravitational force

41. Cyclone Separators or Centrifugal Separator

42.  Centrifugal forced is utilized to separate the
particulate matter from the gas. As centrifugal force is
much greater than gravitational force smaller particles
can be removed (10 to 50 micrometre)

43. Electrostatic Precipitator

44. Electrostatic Precipitator
 It works on the principles of electrical charging of the
particulate matter (-ve charged) and collecting it on a
differently charged (+ve charged ) collecting surface. It
has a very high efficiency of 99% & can remove
particles in the size range of 0.1 micrometer to 1
micrometer effectively.

45. Fabric filter (bag house filter)

46. Fabric filter (bag house filter)
 In this device fabric filter’s out the particulate matter
from the gas stream & allow clear gas to flow. It can
remove particles up to 1 micrometer.

47. Scrubbers
 In scrubber the particulate matter are incorporated in
to liquid droplets & thus are removed from gas stream.
Different types of scrubber includes
 (a) Spray Tower (b) Ventury Scrubber (c) Cyclone
scrubber

48. Spray Tower

49. Control of gaseous pollutants
 The gaseous pollutants can be controlled through the
technique of combustion, absorption & adsorption
 In combustion process oxidizable gaseous pollutants
are completely burnt at a high temperature.This process
is used to control gaseous pollutants in petrochemical,
fertilizer, paint and varnish industry.
 In absorption technique effluent gases are passed
through absorbers containing liquid absorbent that
remove, treat or modify one or more gaseous pollutant.
Liquid absorbent may utilize either chemical or
physical changes to remove pollutants
 In adsorption, the pollutants are adsorbed on a solid
surface. Commonly used adsorbents are activated
carbon, activated alumina, silica gel etc.

50. Control of automobile exhaust
 Automobile exhaust can be controlled by
 The unburnt hydrocarbon in auto emission can be
reduced by use of efficient engines (MPFI, CRDI, TDI
technologies)
 Using lead free petrol
 By using cleaner fuel like CNG
 By proper maintenance of the vehicle
 Developing good mass transportation facility