| 天津市冬季重污染二次有机化学污染特征及VOCs对SOA生成潜势 |
| 摘要点击 2090 全文点击 704 投稿时间：2020-01-13 修订日期：2020-03-06 |
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| 中文关键词 重污染 细颗粒物 二次有机气溶胶(SOA) 挥发性有机物(VOCs) 气溶胶生成系数(FAC) |
| 英文关键词 heavy pollution episode PM2.5 secondary organic aerosol (SOA) volatile organic compounds (VOCs) fractional aerosol coefficient (FAC) |
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| 中文摘要 |
| 基于天津市2019年1～3月超级观测站数据，研究重污染期间二次有机化学污染特征.重污染过程期间SOC约占PM2.5质量的3.1%～3.8%，增长幅度显著高于PM2.5，二次有机化学反应对重污染PM2.5有较大影响.VOCs增长幅度较PM2.5低，可能与VOCs作为前体物生成二次颗粒物而有所消耗有关.乙烷/乙炔比值在2.0以上，但较污染前下降，说明尽管重污染期间气团老化，但活性有所提升.重污染期间VOCs对SOA的生成潜势为0.49～1.21 μg·m-3，芳香烃对SOA生产贡献最大，贡献率大于90%，较污染前芳香烃类SOA生成潜势贡献升幅最大，说明芳香烃类是对SOA形成影响最大的物种. |
| 英文摘要 |
| The characteristics of secondary organic reactions were studied based on supersite monitoring data from January to March, 2019, in Tianjin. During heavy pollution episodes, SOC (secondary organic carbon) accounted for between 3.1% and 3.8% of PM2.5, and the growth rate of SOC was obviously higher than that of PM2.5, thus indicating that secondary organic reactions had a considerable effect on PM2.5. The growth rate of VOCs (volatile organic compounds) was lower than that of PM2.5, which was probably due to the fact that VOCs were consumed as precursors to secondary particles. The ratio of ethane to acetylene was higher than 2.0 during heavy pollution episodes indicating that air masses were old, and the ratio was lower than clean air days showing that the reaction activities were higher than before. During the heavy pollution episodes, the potential formation of SOA (secondary organic aerosol) from VOCs ranged from 0.49 to 1.21 μg·m-3. Among the species, aromatic hydrocarbons contributed the most, whereby the highest contribution exceeded 90%, and their growth rates were also the highest; hence, aromatic hydrocarbons were the VOCs species that had the greatest effect on SOA. |
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