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Comparative Study on Photochemical Reactions of Aromatic Hydrocarbons in Indoor and Outdoor Smog Chambers

실내/외 스모그 챔버에서의 방향족계 탄화수소의 광화학 반응 비교 연구

  • Dong Jong-In (Department of Environmental Engineering, University of Seoul) ;
  • Ahn Heung-Soon (Department of Environmental Engineering, University of Seoul)
  • 동종인 (서울시립대학교 환경공학부) ;
  • 안흥순 (서울시립대학교 환경공학부)
  • Published : 2005.02.01

Abstract

The number of cases exceeding environmental standards of atmospheric ozone in the major cities in Korea has steadily increased during the past decades. In order to understand and analyze the atmospheric reactions in the atmosphere, especially the secondary photochemical reactions, smog chambers studies have been performed very actively by many research groups worldwide. However, these studies have focused on the mechanism of photochemical reactions in high concentration conditions, not at the ambient levels. Therefore, in-depth studies in these conditions are essentially needed to realize exact mechanism in the atmosphere near the earth surface, especially at Korean atmospheric conditions. In this experiment, the mechanism of photochemical smog was examined through a comparative experiment of smog chambers under sun light and black light conditions. The results of our study indicated that concentrations of ozone, aldehyde, and PAN increased as the radiation of light source increases. Photochemical reaction patterns can be considered quite similar for both black light and sun light experiments. Based on our experiments using toluene as a reactant which is present at significant high levels in ambient air relative to other VOCs, it was found that toluene could contribute notably to oxidize NO to $NO_2$, this reaction can eventually generate some other photochemical oxidants such as ozone, aldehyde, and PAN. The results of simulation and experiments generally showed a good agreement quite well except for the case of $O_3$. The restriction of oxidization of NO to $NO_2$ seems to cause this difference, which is mainly from the reaction of peroxy radical itself and other reactants in the real gas.

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References

  1. Seinfeld, J. H. and S. N. Pandis, 1998, Atmospheric Chemistry and Physics, John- Wiley, 140-152pp
  2. Carter, W. P. L., 1993, Environmental Chamber Studies of Maximum Incremental Reactivities of Volatile Organic Compounds, Report to Coordination Research Council
  3. Carter, W. P. L., 1996, The University of California, Riverside, Environmental Chamber Database for Evaluating Oxidant Mechanisms: Indoor Chamber Experiments through 1993, U.S. Environmental Protection Agency (EPA-6001R-96-078a,b)
  4. Chang, T. Y, B. I. Nance. and N. A. Kelly, 1999, Modeling Smog Chamber Measurements of Incremental Reactivities of Volatile Organic Compounds, Atmospheric Environment, 33, 4571-4577 https://doi.org/10.1016/S1352-2310(99)00274-5
  5. Jeffries, H. E., 1995, A Microcomputer System for Testing Kinetics Mechanisms with Chamber Data, U.S.EPA, 1/2, 13-14
  6. Carter, W. P. L. and J. A. Pierce, 1995, Environmental Chamber Studies of Atmospheric Reactivities of Volatile Organic Compounds: Effects of Varying Chamber and Light Source, Coordinating Research Council
  7. Holmes, John. R., 1973, Measurement of Ultraviolet Radiation Intensity in Photochemical Smog Studies, Enviromental Science & Technology, 7, 6
  8. Carter, W. P. L., 2001, Development of a NextGeneration Environmental Chamber Facility for Chemical Mechanism and VOC Reactivity Research, U.S. Environmental Protection Agency, 2-4pp