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Photochemical somog

  2. Name Industrial Smog Photochemical Smog Weather Cool,Damp Sunny Content Particulate,SO2 Nox,O3,Hydrocarbon Chief Sourse Coal Combustion Gasoline Combustion Smog Industrial Smog Or London Smog Photochemical Smog Or Los Angels Smog
  3. Photochemical Smog is an air pollution ,formed when photons of sunlight hit molecules of different kinds of pollutants in the atmosphere
  4. AIR POLLUTANT Primary Air Pollutant NOx , VOCs Secondary Air Pollutant Ozone(O3) , PAN
  5. Process Involving Formation Of Photochemical Smog
  6. Formation of Oxides of Nitrogen N2+O2→2NO 2NO+O2→NO2 NO2+hν→NO+O Photolysis
  7. Formation of Tropospheric Ozone Nitrogen Oxide O∙+O2→O3 NO+O3→NO2+O2
  8. O3+RH→RCO2 ∙+RCHO+R2CO Hydrocarbon O+RH→R∙ + RCO∙ (acyl radical) RCO∙ +O2 →RCO3 ∙ (peroxyacyl radical) RCO3 ∙+ NO2 → RCO3NO2 R=CH3, CH3 + NO2→ CH3CO3NO2
  9. Effect on Human Health & Plants
  10. Smog can irritate and inflame pulmonary membranes, causing chest pains, coughing, and throat irritation. Other illnesses such as colds and pneumonia can also be brought on by exposure to smog. People with asthma problems are under an even greater threat. Even minor exposure to smog may cause these people to get asthma attacks. Smog slowly ruins people's lungs to an extent as great as that of cigarettes.
  12. CHEMICAL SPECIES ANTHROPOGENIC SOURCES ENVIRONMENTAL HEALTH & EFFECTS COMMENTS Nitrogen Oxides (NO2,NO,) • Combustion of gasoline in Automobiles • Gasoline , Coal, Gas Industry • Decrease visibility due to yellowish nature of NO2 • Eye irritation • NO2 responsible for suppressing growth of plants • Prolong exposure to Nitrogen Dioxide increases respiratory infection • May increase the cases of cancer • Only 5% of the total concentratio n of NO2 results From combustion and most is formed from reaction involving NO from lightening, Bacterial action in soil.
  13. Volatile Organic compound(VOC s)  Evaporation of solvents  Incomplete combustion of fossil fuel  Evaporation of fuels  Eye irritation  Respiratory irritation  Decreased visibility due to Blue- brown haze VOCs in the atmosphere includes naturally occurring compounds such as Terpenes from vegetation
  14. Ozone(O3 ) • Formed From Photolysis of NO2 • Harsh Odour • Bronchial constriction • Coughing and Wheezing • Damage Plastics • Retard Plant Growth • Decrease yield of crop • People with asthma and respiratory problems mostly affected by it.It’s 0.1 PPM concentration can reduce half of total photosynthesi s
  15. Peroxy acyl nitrate(PAN) ,and other related compounds • Formed by reaction of NO2 with VOCs • Eye and respirato ry irritation • Cause damage to proteins • Was not detected until recognized in smog,Cause more damage to plants than ozone
  16. Factors affecting Formation of Photochemical Smog
  17. Formation of Different content of photochemical smog in different time of day
  18. Pollutants are rinsed out of the atmosphere with rainfall Photochemical Smog can be blown away by wind Temperature Inversion increases photochemical smog Role of Topography in smog formation
  19. Mitigation measures For Photochemical Smog
  20. Catalytic Converter
  21. Free Radical Trap Free Radical Traps When Sprayed in the atmosphere Produce Free radical Combine with free radical O*,R*,RO* radicals Free radical traps slows down the reaction N2+O2→2NO 2NO+O2→2NO2 2-6 Hr 6-12 hr
  22. Diethyl HYdroxylamine
  23. Petrol reformatio n 1/10 Aromatic hydrocarbon Oxygenated fuel C(CH3)3O Tertiary butyl ether Emission of oxides of Nitrogen is reduced Petrol containing oxygena Low temperature Emission of VOCs and N Supresess smog formati
  24. i. Try to use the vehicles at minimal level and check the engine’s smoke emission frequently ii. Prevent high usage of coals,which result in heavy smog iii. Reduction of fumes from metal-working and other industrial plants; iv. Buy green electricity-produced by low-or even zero-pollution facilities. v. Reduce pesticide use. vi. Consumers can reduce VOC emissions by avoiding paints with labels that clearly indicate VOC limits are high. Switching to water-based paint is also useful.