This document discusses air pollution and its various aspects. It begins with an introduction to the atmosphere and how air pollution affects living organisms. It then covers classifications of air pollutants based on origin and composition. Sources of air pollution are discussed as natural sources like volcanic eruptions and forest fires, and man-made sources such as industries, vehicles, and agriculture. Common air pollutants like oxides of carbon, nitrogen, and sulfur are described along with their sources, effects, and control measures. Particulate matter is also discussed regarding its sources, effects, and methods to control emissions.

1. Environmental Engineering
Lecture 5: - Air Pollution

2. Introduction

3. Environmental. Eng. - Air Pollution 3
L Ogutu
23.06.2022

4. Introduction
The mantle of gases, which surrounds of our
planet, is referred to as atmosphere.
It is a complex mixture of gases, water vapours
and a variety of fine particulate material.
Most of these gases are compressed in
lowermost layer of the atmosphere.
"Pressure decreases as we move upward.
Environmental. Eng. - Air Pollution

5. Introduction
Living beings inhale a considerable quantity of
air. Therefore pollution of air, have profound
influence on living organisms.
Unfortunately, an alarming quantity of gases,
particulate material, fumes, vapours and smoke
is discharged daily into the atmosphere.
Environmental. Eng. - Air Pollution

6. Classification of Air
Pollution

7. Classification of Air Pollutants
Based on Origin
a. Primary pollutants e.g.SOx, NOx,HC
b. Secondary pollutants e.g. 03
Environmental. Eng. - Air Pollution

8. Classification of Air Pollutants
Primary Pollutants
These are pollutants which are directly emitted
or persist in the form in which it is added to the
environment from one source e.g. oxides of
carbon, nitrogen and sulphur oxides, radioactive
substances, hydrocarbon etc.
Environmental. Eng. - Air Pollution

9. Classification of Air Pollutants
Secondary Air Pollutants
These are pollutants formed by interaction of
primary pollutants among each other e.g. ozone
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10. Classification of Air Pollutants
According to chemical composition
1
. Organic pollutants
2. Synthetic organic pollutants
3. Inorganic pollutants
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11. Sources of Air Pollution

12. Sources of Air Pollution
Classified as:
a. Natural sources of air pollution
b. Manmade sources of air pollution
[Anthropogenic]
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13. Natural Sources of Air Pollution
Natural source which generates air pollutants is
due to natural cyclic action from earth sources.
The pollution due to natural cyclic action is
continuous phenomenon, therefore it is difficult
to control.
The natural sources are:
Volcanic eruption, release harmful gases and
ash,
The forest fire releases smoke and gases
Environmental. Eng. - Air Pollution

14. Natural Sources of Air Pollution
The forest fire releases smoke and gases
Sea salt spray
Pollen grains from flower/plants
Dust storm
Decay of organic matter releases gas like
methane.
These are the natural source of pollution which
cannot be controlled by human being.
ental. Eng. * Air Pollution
23.06.2022

15. Manmade Sources of Air Pollution
The man-made source causes severe damages to the
environment.
The major sources of anthropogenic degradation are:
a. population explosion,
b. urbanization,
c. industrialization,
d. revolution in automobile sector,
e. domestic pollution,
f. deforestation, etc.
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23.06.2022 L Ogutii

16. Manmade Sources of Air Pollution
Manmade sources include:
The industries produce large amount of
S04, N03,HN3 HF.HC1and H2S gases along
with suspended particulate matter from their
stack.
The vehicular exhaust results into harmful
gases due to burning of fossil fuels.
The domestic activities like use of insecticides
for cleaning home painting activities etc.
Environmental. Eng. - Air Pollution

17. Manmade Sources of Air Pollution
Manmade sources include:
Open burning and incineration
Modern agricultural techniques like spraying of pesticides
and weed control medicines
Nuclear explosion and explosives release radioactive
pollutants.
Construction of dams, buildings, bridges and road etc.
generate air pollution.
Mining and quarry activities
Painting of furniture and wall
Environmental. Eng. - Air Pollution
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18. Common Pollutants and
Their Effects

19. Oxides of Carbon

20. Oxides of carbon
Carbon monoxide and carbon dioxides.
Carbon monoxide is colourless, odourless, toxic
gas which has higher affinity for hemoglobin
{HB] than oxygen. Hence,it combines with
hemoglobin forms carboxy hemoglobin which is
dangerous to life.
02 + Hb = 02Hb [oxyhemoglobin]
In the presence of carbon dioxide
02Hb + CO =COHb [carboxyhemoglobin] + 02
Environmental. Eng. - Air Pollution

21. Sources of Carbon
Incomplete combustion of fuel
Jet engine emissions
Coal mining
Tobacco smoking
Forest fire, etc
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22. Effects of Carbon
Headache visual difficulties and paralysis
As carbon monoxide combines with
hemoglobin in blood and forms
carboxyhemoglobin, then capacity of the blood
to carry oxygen to body tissues reduces which
endanger life.
Carbon monoxide forms smog which leads to
serious respiratory problems.
Increase rate of accidents due to CO poisoning.
Environmental. Eng. - Air Pollution

23. Control measures
Use of catalytic converter in combustion
engines.
Adsorption, absorption and condensation.
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24. Oxides of Nitrogen

25. Control measures
Oxides of nitrogen are:
NO,N02,
The nitric oxide, nitrogen dioxide and nitrous
oxide are the major concerned air pollutant.
NO is colourless gas and highly soluble in water.
N02 is reddish brown gas with pungent odour,
slightly soluble in water and acts as oxidizing
agent.
N20, N02, N203, N20^
,etc
Environmental. Eng. - Air Pollution

26. Sources of oxides of nitrogen
Bacterial decomposition of organic matter
"Automobile exhaust
"Coal fired and gas fired furnace
Fertilizer industry
Domestic burning fuel
Explosive industry
Lightening and thunders
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27. Effects of oxides of nitrogen
NO combines with hemoglobin and reduces
oxygen carrying capacity of blood,.
It causes respiratory irritation, headache,
bronchitis.
Loss of appetite, corrosion of teeth
Nitrogen oxide and hydrocarbon form smog in
sunlight which reduces the visibility on road.
Causes eye irritation
Environmental. Eng. - Air Pollution

28. Effects of oxides of nitrogen
Reacts with atmospheric moisture and forms
nitric acid resulting into acid rain.
"Reacts with volatile carbon and produces
ground level ozone which is a dangerous air
pollutant at respiratory level.
Environmental. Eng. - Air Pollution

29. Control Measures of oxides of nitrogen
Catalytic converter can be used in automobiles
to clean emissions
Chemical absorption process should use to
remove NOx
In power plant, the emission of NOx can be
controlled at source of burning fuel at relatively
at low temperature in presence of excess air.
Environmental. Eng. - Air Pollution

30. Oxides of Sulphur

31. Oxides of Sulphur
Sulphur dioxide is colourless and soluble in
water.
"It is pungent and suffocating odour.
The oxidation of S02 into S03 in the favourable
atmosphere conditions.
In humid environment S03 combines with
water vapour and forms H2S04 which result
into acid rain.
Environmental. Eng. - Air Pollution

32. Sources of Oxides of Sulphur
Burning of fossil fuel
Coal fired power plants
"Refineries
Chemical industries
Transportation
Fertilizer industries
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33. Effects of Oxides of Sulphur
Acid rain when S03 combines with water
vapour in the atmosphere
Respiratory irritations
Prolonged exposure causes danger to building
due to acidic nature
Impairment in pulmonary function
It promotes corrosion in metal and also affects
paper, leather, cloth, etc.
Environmental. Eng. - Air Pollution

34. Controlled Measures of Oxides of Sulphur
Use of gas by replacing coal as a fuel
"Control at source like removal of SOx from
emission gas by proving scrubbing units in the
industries.
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35. Particulate Matter

36. Particulate Matter
The particulate matter is complex solid or liquid
aerosols droplets in the air which remains in
suspension. Particulate matter can be
differentiated according to size, mode of
formation and its physical state.
It may be classified as aerosols, dust, smoke,
fumes, mist, fog, fly ash, etc.
Environmental. Eng. - Air Pollution

37. Sources of Particulate Matter
Natural source like volcanic eruption
Dust blowing, cyclone, wind blowing, forest fire
Mining stone crushing
Agricultural burning
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38. Effects of Particulate Matter
Reduce visibility
Some air borne toxic metal are carcinogenic
Dust causes allergy and respiratory diseases
"Dust contain silica causes silicosis
"Smog has toxic effects on man plants and
animals due to pollution.
Environmental. Eng. - Air Pollution

39. Control of Particulate Matter
Installation of filters, gravity settling chambers,
cyclone collector, wet scrubbers and
electrostatic precipitators.
Environmental. Eng. - Air Pollution

40. THE END
Thank You
Ogutu
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