AIR POLLUTION CONTROL course material by Prof S S JAHAGIRDAR,NKOCET,SOLAPUR for BE (CIVIL ) students of Solapur university. Content will be also useful for SHIVAJI and PUNE university students

1. L-5
Units of measurement
and definitions
Air Pollution and Control
(Elective-I)

2. Contents of unit-II
• L-4  Classification of
pollutants Quantity and
composition of particulate &
gaseous pollutant.
pollutant.
• Units of measurement (Already
(Already
covered).

3. Other way of classifying
air pollutants

4. No.
Group
Examples
1
Sulphur compounds
2
Nitrogen compounds
SO2, SO3, H2S,
Mercaptans
NO, NO2, NH3
3
Oxygen compounds
O3, CO, CO2
4
Halogen compounds
HF, HCl
5
Organic compounds
6
Radioactive
compounds
Aldehydes,
hydrocarbons
Radioactive
gases

5. Natural Contaminants
 Pollen is important natural
contaminant because of its peculiar
properties of irritation and allergy
sometimes leading to bronchitis,
asthma and dermatitis.
 Pollen grains are discharged into the
atmosphere from plants etc. The air
transported pollen grains range
mainly between 10 and 50 microns.

6. Aerosols
• Aerosols:
Aerosols
refer
to
the
dispersion of solid or liquid particles of
microscopic size in the air. It can also be
defined as a colloidal system in which
the dispersion medium is gas and the
dispersed phase is solid or liquid.
• The diameter of the aerosol may range
from 0.01 (or less) micron to 100 micron.
The various aerosols are as follows:-

7. Smoke
• Smoke consists of finely
divided particles produced
by incomplete combustion
• Size- less than 1 micron
• Coal smoke – 0.2 to 0.01
micron
• Oil smoke – 1.0 to 0.03
micron

8. Mists
• This term refers to a low
concentration dispersion of
liquid particles of large size.
• Size- 500 to 40 micron

9. Fog
• Fog refers to visible aerosols in
which dispersed medium is
liquid.
• Formation by condensation is
usually implied.
• Reduces visibility
• Size- 40 to 1.0 micron

10. Fumes
• These
are
solid
particles
generated by condensation from
gaseous state, generally after
volatilization
from
melted
surfaces
and
often
accompanied by a chemical
reaction such as oxidation.
• Size varies from 0.1 to 1 micron

11. SOURCES OF
ATMOSPHERIC DUST

12. No.
Sources
Examples
1
Combustion
Fuel burning (Coal, wood, fuel oil)
Incineration/burning (house and
municipal garbage)
2
Material
Loading and unloading (sand,
handling and gravel, coal, ores, lime, cement)
processing
Crushing and grinding (ores,
stone, cement, rocks, chemicals)
Food processing (Flour, corn
starch, grains)
Cutting and forming (saw mills,
wall boards, plastics)
Metallurgical (Foundries and
smelters)
Industrial (Paper, textile
manufacture etc. )

13. No.
Sources
3
Earth
moving
operations
4
Examples
Construction (roads,
buildings, dams, sites
clearance)
Agricultural (soil filling,
land operations)
Mining (Blasting)
Miscellaneo House cleaning
us
Mud road cleaning
Crop spraying
Poultry feeding
Engine exhaust

15. Gases
• Following are the main air pollutant gases
(i) Sulphur dioxide:
It is a major air
pollutant gas produced by the combustion
of fuels like coal. The main source of
electricity production is by burning of fossil
fuels in India and the whole world. The
sulphur content of the coal varies from 1 to
4% and fortunately the Indian coal is low in
sulphur content. SO2 is also produced in the
metallurgical operations.

16. (ii)Oxides of nitrogen:
Oxides of
nitrogen are produced either in the
production of nitric acid or in the
automobile exhausts and as the effluent of
power plants. Out of the seven oxides of
Nitrogen (N2O, NO, NO2, NO3, N2O3, N2O4,
N2O5) only nitric oxide and nitrogen dioxide
are classified as the main pollutants. All the
oxides of nitrogen are collectively known as
NOX.

17. (iii) Carbon monoxide:
It is
produced because of the incomplete
combustion of coal and other
petroleum products. It is produced in
the exhaust of automobiles. In the
pollution check of vehicles mainly CO
and unburnt hydrocarbons are
measured.

18. (iv) Hydrogen sulphide:
Hydrogen
Sulphide is an obnoxious (bad
smelling) gas. It is produced mainly by
the anaerobic (in absence of air)
decomposition of organic matter.
Other air polluting sulphur compounds
are methyl mercaptan and dimethyle
sulphide etc.

19. (v) Hydrogen fluoride:
It is an
important pollutant even in very low
concentrations. It is produced in the
manufacturing of phosphate
fertilizers.

20. (vi) Chlorine and hydrogen chloride:
chloride:
It is mixed in the air either from the
leakages from water treatment plants or
other industries where it is produced or
used. Hydrogen chloride is also evolved in
various industrial chemical processes. The
main effect of chlorine is respiratory
irritation which may be fatal.

21. (vii) Ozone:
It is a desirable gas in
the upper layers of atmosphere as it
absorbs the UV radiation of sunlight.
But near the earth surface it is a
poisonous gas. It makes poisonous
chemicals by photochemical
reactions.

22. (viii) Aldehydes: They are
produced by the incomplete
oxidation of motor fuels and
lubricating oil. They may also be
formed because of photochemical
reactions. Formaldehydes are
irritating to the eyes.

25. Concentration of air
pollutants
• It is common practice to
express the quantities of
gaseous pollutants present in
air as parts per million (ppm),
thus,

26. • Therefore,
0.0001 % by volume = 1ppm
Or
1 % by volume = 104 ppm

27. Mass of pollutant
• The mass of pollutants is
expressed as micrograms/cu. M
of air
• i.e.

28. Relation between ppm
and micrograms/cu.m
General relation
(p)

29. Where,
T= Temperature in Kelvin= 273 + temp in degree Celsius
Mi = molecular weight of specie i
R= universal gas constant
p= pressure

30. ]x
103
1. at 250C and 1 atm
pressure (760 mm of Hg)

31. 2. At 0oC and 1 atm
pressure (760 mm of Hg)
22.41

32. important data required
for problems
• For calculation of Molecular wt we
must know atomic wts of different
elements
• O = 16
•H=1
• C = 12
• S = 32
• N =14

33. Try this small but simple
test
• Calculate molecular wt.s of
1. CO2
2. NO
3. SO2

34. Objective questions
1. The air transported pollen grains
range mainly between
________and________ microns.
2. ______________ consists of finely
divided particles produced by
incomplete combustion.
3. __________refers to visible aerosols in
which dispersed medium is liquid.

35. 4. ________________ is oxidant gas
formed by photochemical
reaction.
5. _______________ are produced by
the incomplete oxidation of
motor fuels and lubricating oil.
6. 1 % by volume = _____ ppm

36. Theory questions
Q1. Define the following
1. Fumes
2. Smoke
3. Aerosol
4. Mist
5. Fog
Q2. Give relation between ppm and
 gm/m3 at different conditions