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The Control Method of Photochemical Smog. Lee Jin-Young 2200938. University of Incheon Department of Civil & Environmental System Engineering. Contents. Introduction ⑴ Photochemical smog Main subject ⑴ Qualitative relationship ⑵ Major factors
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The Control Method of Photochemical Smog Lee Jin-Young 2200938 University of Incheon Department of Civil & Environmental System Engineering Term project 2006
Contents • Introduction ⑴ Photochemical smog • Main subject ⑴ Qualitative relationship ⑵ Major factors ⑶ The effects of photochemical smog ⑷ Anatomy of a smog ⑸ Causes of photochemical smog • Conclusion ⑴ The control of photochemical smog Term project 2006
Photochemical Smog • Increase of gasoline use is one of the major cause of smog generation • The term smog was used to describe the glaring bluish-brownish, ozone-laden haze that enveloped the basin from late morning to mid-afternoon when a certain combination of weather condition existed • Warm and stagnant atmospheric conditions Term project 2006
Qualitative Relationship • PPL = photochemical pollution level • ROG = concentration of reactive organic gases • NOX = concentration of oxides of nitrogen Term project 2006
Factors responsible for photochemical smog • The spatial and temporal distribution of emissions of NOx and VOCS (Both anthropogenic and biogenic) • The composition of the emitted VOCS • The spatial and temporal variations in the wind field • The dynamics of the boundary layer, including stability and the level of mixing Term project 2006
Factors responsible for photochemical smog • The chemical reactions of solar isolation and temperature • The loss of ozone and ozone precursors by dry deposition • The ambient background of VOCS, NOx, and other species in, immediately upwind, and above the regions of study Term project 2006
EFFECT OF PHOTOCHEMICAL SMOG Term project 2006
Anatomy of a Smog • NO2 + hv NO + O • O + O2 O3 • O3 + NO NO2 +O2 • Equation explain the diffusion of NOx in presence of light energy and formation of ozone. • While the presence of NO2 is required to form O3, the nitro dioxide photolytic cycle by itself does not generate net ozone, and can’t explain ozone accumulation Term project 2006
Anatomy of a Smog • ROG + O+ O3 R• + RCO + RO• + OH• • R• + O2 RO2• • RO2 • + NO RO• + NO2 Term project 2006
Causes of Photochemical Smog Term project 2006
The Control of Photochemical Smog • The approach to controlling smog has been to reduce emissions of its precursors(ROGX and NOX) Term project 2006
Propane Term project 2006
Toluene Term project 2006
n-butane Term project 2006
Conclusion • Stagnant of air is important of photochemical smog • Light energy is play vital role for the formation of ozone • When ROG/NOX is nearly between 5 and 6,the two species have equal rates of reacting with the OH• • If this ratio is much larger than 6, there is a shortage of NO that can be oxidized to NO2 andozone production is controlled by the amount of NOX available • On the other hand,when ROG/NOX is on the other of 5 or less,the ready availability of NOX makes the formation rate of ozone dependent on ROG Term project 2006