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Air Pollution Control

  2. what is air pollution? • Air pollution is the excessive concentration of foreign matter in the air which adversely affects the well being of the individual or causes damage to the property. ~American Medical Association • It is the disturbance caused due to presence of unwanted, impure & harmful particles in the air or atmosphere.
  3. Why should we study air pollution?  Air pollution can cause death, impair health, reduce visibility, bring about vast economic losses & contribute to general deterioration of both cities and country-side.  It can cause intangible losses to historical monuments such as Taj Mahal which is believed to be badly affected by air pollution.  The study on air pollution helps engineers to apply their ingenuity & problem-solving abilities to eliminate air pollution where it exists and restoring the natural environment.  Example : Invention of E-Bikes to reduce the risk of pollution caused by bikes consuming petroleum products
  4. Normal composition of air Nitrogen(78%) Oxygen (20.6%) carbondioxide and other gases (0.03%) inert gases (mainly Argon) (0.97%) water vapour (1%)
  5. Sources of air pollution S.No. Class Aerosols Gases and Vapours 1. Combustion processes (domestic burning, thermal power plants, aeroplanes & railways.also refuse burning) Dust, fume, smoke. SO2, NO2, CO, organic vapours, odours. 2. Chemical processes Dust, fume, mist SO2, CO, NH3, NO2, (process dependent) 3. Petroleum operations Dust, mist SO2, H2S, NH3, CO, hydro-carbons, mercaptants. 4. Metallurgical process Dust, fume SO2, CO Fluorides, organic vapours. 5. Mineral processing Dust, fume SO2, CO, Fluorides, organic vapours 6. Food & Feed Operations Dust, mist Odourous materials, organic phosphates 7. Agricultural activities Dust, mist, smoke, fly ash organic vapours 8. Nuclear energy programmes Dust Radioactive gases
  6. Episodes of air pollution • Episodes of air pollution are disastrous air pollution events in the world. • Some of them are: S.No . Month and year Place Mortality 1. December, 1930 Meuse Valley (Belgium) 63 2. October, 1948 Donora (Pennsylvania) 20 3. November, 1950 Poza Rica (Mexico) 22 4. December, 1952 London 4000 5. November, 1953 New York 220 6. January, 1956 London 1000 7. December, 1957 London 750 8. December, 1984 Bhopal (India) 2000
  7. Images of the incidents Meuse Valley Donora Bhopal
  8. Classifications of air pollutants Pollutants Natural Contaminants Natural fog, Pollen grains, bacteria, etc. Aerosols (Particulates) Dust, smoke, mists, etc. Gases & Vapours SO2, O3, NO2 etc.
  9. 1. Natural Contaminants • Natural Contaminants occur due to natural phenomena itself. • These include volcanic eruptions, natural fog, pollen grains, bacteria. • These air-borne pollutants are significant because of the allergic responses produced in sensitive individuals.
  10. Volcanic Eruption
  11. 2. Aerosols • Aerosols refer to dispersion of solid or liquid particles of microscopic size in gaseous media, such as dust, smoke, or mist. • It can also be defined as a colloidal system in which the dispersion medium is gas &the dispersed phase is solid or liquid. • It includes dust, smoke, mists, fog, fumes etc.
  12. 3. Gases • The following are some of the gases in the air pollutants. Sulphhur Dioxide • The main source is the combustion of fuels. Hydrogen Sulphide • Due to Anaerobic Biological decay process on land, in marshes & in oceans. Ozone • It exists in great abundance under natural conditions in the upper atmosphere.
  13. Other Classification of air pollutants • Primary air pollutants: Primary air pollutants are those which are emitted directly from identifiable sources.  Secondary air Pollutants: Secondary air Pollutants are those which are produced in the air by the interaction among two or more primary pollutants, or by reaction with normal atmospheric constituents, with or without photoactivation.
  14. Examples of primary air pollutants • Finer particles (less than 100 µ in diameter) • Coarse particles (greater than 100 µin diameter) • Sulphur Compounds • Oxides of nitrogen • Carbon monoxide • Halogen compounds • Organic compounds • Radioactive compounds
  15. Examples of secondary air pollutants • Ozone • Formaldehyde • PAN (Peroxy Acetyl Nitrate) • Photochemical smog • Formation of acid mists (H2SO4) due to reaction of sulphur dioxide and dissolved oxygen, when water droplets are present in the atmosphere.
  16. Classification according to Emission Inventory Source Total Sources Stationary Sources Point Sources Area Sources Mobile Sources Line Sources Area Sources
  17. Sub classifications Point Sources Industrial processing Power Plants Fuel Combustion (coal, oil, gas) Solid Waste disposal Miscellaneous Area Sources Residential heating Institutional & Commercial heating On site incineration Open burning Evaporative losses Miscellaneous Line Sources High way Vehicles Railroad Locomotives Channel Vessels Area Sources Motor Vehicles (light, medium, heavy duty) Railyard Locomotives Port Vessels Aircraft (airports) Miscellaneous
  18. Thank you Prepared by M.Faiyaz Ahmed Khaleel