The Control Method of Photochemical Smog Lee Jin-Young Civil & Environmental System Engineering 2006 년 6 월 12 일

Civil & Environmental System Engineering Civil & Environmental System Engineering 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

2006 년 6 월 12 일 Civil & Environmental System Engineering Civil & Environmental System Engineering Photochemical Smog Utilization of gasoline increase with the increase of vehicle generation of smoke increase 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

2006 년 6 월 12 일 Civil & Environmental System Engineering Civil & Environmental System Engineering Qualitative Relationship PPL = photochemical pollution level ROG = concentration of reactive organic gases NO X = concentration of oxides of nitrogen

2006 년 6 월 12 일 Civil & Environmental System Engineering Civil & Environmental System Engineering Major Factors The spatial and temporal distribution of emissions of NO x and VOC S (Both anthropogenic and biognic) The composition of the emitted VOC S The spatial and temporal variations in the wind fields The dynamics of the boundary layer, including stability and the level of mixing

2006 년 6 월 12 일 Civil & Environmental System Engineering Civil & Environmental System Engineering The chemical reactions of solar insolation and temperature The loss of ozone and ozone precursors by dry deposition The ambient background of VOC S, NO x, and other species in, immediately upwind, and above the regions of study

2006 년 6 월 12 일 Civil & Environmental System Engineering Civil & Environmental System Engineering The Effects of Photochemical Smog

2006 년 6 월 12 일 Civil & Environmental System Engineering Civil & Environmental System Engineering Anatomy of a Smog NO 2 + hv NO + O O + O 2 O 3 O 3 + NO NO 2 +O 2 But, while the presence of NO 2 is required to form O 3, the nitro dioxide photolytic cycle by itself does not generate net ozone, and can ’ t explain ozone accumulation

2006 년 6 월 12 일 Civil & Environmental System Engineering Civil & Environmental System Engineering ROG + O+ O 3 R + RCO + RO + OH R + O 2 RO 2 RO 2 + NO RO + NO 2

2006 년 6 월 12 일 Civil & Environmental System Engineering Civil & Environmental System Engineering Causes of Photochemical Smog

2006 년 6 월 12 일 Civil & Environmental System Engineering Civil & Environmental System Engineering The Control of Photochemical Smog The approach to controlling smog has been to reduce emissions of its precursors(ROG X and NO X )

2006 년 6 월 12 일 Civil & Environmental System Engineering Civil & Environmental System Engineering Propane

2006 년 6 월 12 일 Civil & Environmental System Engineering Civil & Environmental System Engineering Toluene

2006 년 6 월 12 일 Civil & Environmental System Engineering Civil & Environmental System Engineering n-butane

2006 년 6 월 12 일 Civil & Environmental System Engineering Civil & Environmental System Engineering Conclusion When ROG/NO X 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 NO 2 and ozone production is controlled by the amount of NO X available On the other hand,when ROG/NO X is on the other of 5 or less,the ready availability of NO X makes the formation rate of ozone dependent on ROG