| Summary: | 碩士 === 崑山科技大學 === 環境工程研究所 === 93 === Photochemical ozone is formed from nitrogen oxide and volatile organic compounds through non-linear interactions, and the relationship between ozone and precursor pollutants will be different from place to place due to the emissions distribution and meteorology. VOCs and oxides of nitrogen form ozone and photochemical smog and cause secondary pollution under adequate conditions of sunlight and photochemical reaction.
This study investigates a VOC contributes to ozone formation in a photochemical air pollution episode is its "incremental reactivity" for that episode. Field sampling work for the gasoline vehicles and O3, NO, and VOC concentrations will be measured after different reacted times during the photochemical smog experiment. The VOC concentrations were quantified by GC/MS and FTIR, and the single VOC of higher photochemical reactivity were estimated.The incremental reactivity of the single VOC（higher photochemical reactivity）are calculated by the above pollutants analyzed data. A series of the chamber experiments were carried out to assess the tendency of single VOC（m-Xylene、Isoprene）to promote ozone formation in photochemical smog.
The result of Field sampling work for a series of smog chamber experiments indicated that higher NOx had higher smog production, but the opportune moment of the ozone generation delayed. The correlation coefficient (R-squre) between smog production and ozoce emissions for all test gasoline vehicles was 0.32-0.91. The decomposd efficiencies of higher photochemical VOCs are 20-50% during one hour for the VOCs of higher maximum incremental reactivities (MIR). For theVOCs with lower MIR, the photolysis happened slowly on the initial stage, which generated the higher decay after eight hours. The measured values of MIR for the above VOC are 11.4, 8.7 g O3/g VOC,higher than those by Carter 11.0, 8.2 gO3/gVOC.
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