| 上海城区典型污染过程VOCs特征及臭氧潜势分析 |
| 摘要点击 4530 全文点击 1791 投稿时间：2011-06-23 修订日期：2011-08-11 |
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| 中文关键词 典型污染 挥发性有机物 最大臭氧生成潜势量 增量反应性 |
| 英文关键词 typical air pollution volatile organic compounds maximum ozone formation potential maximum incremental reactivity |
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| 中文摘要 |
| 利用在线气相色谱-氢火焰离子化 (GC-FID) 监测系统对上海市城区典型污染前、污染中和污染后的55种挥发性有机物(VOCs)进行了自动连续监测,分析了各个阶段VOCs (C2～C12)体积分数、物种变化特征.结果表明上海市城区典型污染前VOCs平均体积分数为27×10-9; 污染中VOCs体积分数迅速增加,比污染前高3倍,达到87×10-9; 具体以烷烃最高(35.2×10-9)、芳香烃次之(30.0×10-9)、烯烃最低(21.6×10-9); 用最大臭氧生成潜势量( Φ OFP)对不同污染阶段污染VOCs大气活性进行了评估,结果表明不同污染阶段VOCs的 Φ OFP均呈现污染前<污染后<污染中的变化特征.污染前期的 Φ OFP依次是芳香烃(53.0%)>烯烃(36.1%)>烷烃(11.7%); 污染中期的 Φ OFP依次是芳香烃(54.7%)>烯烃(36.7%)>烷烃(9.8%); 污染后期 Φ OFP则依次是烯烃(52.7%)>芳香烃(36.0%)>烷烃(13.2%).具体关键活性物种主要包括甲苯、间、对二甲苯、1, 3-丁二烯、乙烯、丙烯等芳香烃和烯烃物种,具体以烯烃C2～C4为主,芳香烃C6～C8为主. 不同污染阶段O3与 Φ OFP之间存在典型的非线性负相关关系,并且 Φ OFP转化为O3的量均小于20%,说明臭氧浓度仍有很大上升空间; 这对定量评估大气中VOCs对臭氧的影响具有重要意义. |
| 英文摘要 |
| The concentration, speciation and chemical reactivity of ambient volatile organic compounds (VOCs) in shanghai city were analyzed and measured by using online gas chromatography with flame ionization detection systems (GC-FID)during a typical air pollution episode(from Oct.30th to Nov. 2nd, 2010) and 55 kinds of VOCs were detected. The results show that averaged concentrations of VOCs was 27×10-9 before the episode, and then dramatically increased by 3 times(87 ×10-9)in the episode than the former, the main components were alkanes(35.2 ×10-9), aromatics(30.0 ×10-9), alkenes(21.6 ×10-9). Furthermore, the maximum ozone formation potential( Φ OFP) is analyzed and showed that Φ OFP (in the episode)> Φ OFP (after the episode) Φ OFP (before the episode). Before the episode, the percent of Φ OFP for aromatics 53.0%, alkenes 36.1% and alkanes 11.7%; in the episode, the percent of Φ OFP for aromatics 54.7%, alkenes 36.7% and alkanes 9.8%; after the episode, the percent of Φ OFP for alkenes 52.7%, aromatics 36.0% and alkanes 13.2%. Alkenes (C2-C4)and aromatics (C6-C8)are the main components for the ozone formation, namely toluene, m,p-xylene, 1, 3-butadiene, propene, ethene et al. In addition, the relationship is negative and nonlinear between the O3 and Φ OFP. And efficiencies of Φ OFP formed into O3 are below 20.0% in different stage of episode. This is very important and meaningful for the quantitative evaluate the influence of VOCs towards O3. |
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