BIRLA VISHWAKARMA MAHAVIDHYALAYA SUB- ENVIRONMENTAL ENGINEERING TOPIC- AMBIENT AIR POLLUTION Prepared by : Snehal Patel ( ) Pallavi Rana ( ) B.E. (CIVIL) BATCH : B2 Guided By : Prof. R.L.Patel

CONTENT : Introduction Components of atmospheric air Classification of air pollutants Sources of air pollution Effects of air pollution Control of air pollution References

INTRODUCTION :  Air pollution is defined as the presence of unwanted and undesirable particles and gases (in sufficient quantity and duration) in the air which may have adverse effect on human beings, animals, plants, vegetation and important structures.  Air pollution is of public health concern and can occur as: 1- Indoor air pollution – Micro scale 2- Outdoor air pollution – Meso scale 3- Air pollution at global level –Macro scale

COMPONENT OF ATMOSPHERIC AIR :  Atmospheric air is a mixture of various gases, water, vapour and particular matters. The major gases present in atmospheric air are nitrogen (78%), oxygen (21%), argon(.9-1%) and carbon dioxide. The important minor gases are neon, helium, methane, hydrogen and ozone.  Although, the total mass of the global atmosphere is approximately 5.14* 1015 tons it is still only approximately one millionth of the earth’s total mass.

CLASSIFICATION OF AIR POLLUTANTS : The air pollution may be classified on the following basis: 1) Based on origin : According to the origin the air pollutants are classified as; (a) Primary air pollutants, (b) Secondary air pollutants. (a) Primary air pollutants: Primary air pollutants are those which are directly emitted from the source into the atmosphere and remains in the same form into atmosphere.

Continue…. For example : Sulphur oxides, Nitrogen oxides, Carbon monoxide, Hydrocarbons, Radioactive materials etc. These air pollutants are emitted by man made sources like, Transportation, Fuel combustion, Solid waste disposal etc. (b) Secondary air pollutants: Secondary air pollutants are those which are formed by chemical reaction along primary pollutants and atmospheric chemical species For example ; Ozone Sulphur trioxide Petroxyacyl nitrate Ketones Photo chemical smog etc.

Continue…. 2) Based on state of matter : According to the state in which air pollutants are found they are classified as ; (a) Gaseous air pollutants (b) Particulate air pollutants. (a)Gaseous air pollutants : The most common gaseous air pollutants are ; * Carbon monoxide * Carbon dioxide * Nitrogen oxide * Sulphur oxide * Hydrocarbons * Photo chemical oxidants etc.

Continue…. (b) Particulate air pollutants : They are finely divided, air borne, solid and liquid particles which remain for many long time in the air, in suspension. Depending upon their size and mode of formation they are classified as follow : Aerosols, Dust, Fumes, Smoke, Mist, Fog, Flay ash etc. 3) Based on presence on environment : According to the presence of pollutants in the environment they are classified as ; (a) Indoor air pollutants (b) Outdoor air pollutants

Continue…. (a) Indoor air pollutants : Cleaning agents Pesticides Paints, varnishes Cigarette smoke Gases from stoves Microbes like bacteria, viruses, fungi etc. (b) Outdoor air pollutants : Automobile pollutants Industrial pollutants Mining pollutants Natural emissions from decaying organic matter and animals etc.

SOURCES OF AIR POLLUTION : They are classified in two groups ; (1) Natural sources (2) Man made sources. (1) Natural sources : The different form of Natural sources are ; -Atmospheric action -Volcanic eruptions -Marshy places -Dust storms, electric storm -Microorganisms -Radioactive substances

2) Man made source : The following are the man made sources : -Automobile exhaust -Industries -Combustion of fuel -Mining -Air craft -Agricultural activity -Thermal and nuclear power plant -Construction material

EFFECTS OF AIR POLLUTION : Some aromatic hydrocarbons may cause cancer Atmospheric dust containing silica may cause silicosis. Pollens initiate asthamatic attacks. Nickel particulates in tobacco smoke result in respiratory damage. Radioactive substances cause long diseases and affect kidney, liver, brain. Air borne asbestos and toxic metals are carcinogenic. Heavy metals like lead may cause poisoning effects on nervous system, damage to kidney. Mercury from combustion of fossil fuels, plants result in brain and kidney damage.

CONTROL OF AIR POLLUTION : Following measures can be taken to control air pollution :  Dilution  Zoning  Control at source (1) Dilution : If the pollutant are carried away to some distance or taken to high altitudes, they are reduced in concentration by diffusion and dilution. The pollutant are taken to high altitudes by means of tall stacks i.e. high rise chimneys. The height of the stack should be such that the maximum ground level concentration, which varies inversely with the space of the stack height, in within the permissible limits.

2) Zoning : Air pollution can be effectively controlled by adopting the zoning system at the planning stage itself. The ‘ exclusive zoning system ‘ which provides for compatible uses for each zone, excluding other uses. In this system, a separate zone is set aside for industries known as industrial zone, located away from the residential zone. This will result in low concentration of pollutants in the air of residential area. 3) Control at source : This method is known as ‘ air pollution prevention at sources’. This can be achieved through : 1) Raw material changes 2) process changes 3) Equipment modification or replacement.

References : Air pollution.google.com Air pollution.gov.in Pollution control board of indioa.gia.com

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