| 2012~2013年间北京市PM2.5中水溶性离子时空分布规律及相关性分析 |
| 摘要点击 7371 全文点击 3173 投稿时间：2014-07-18 修订日期：2014-10-29 |
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| 中文关键词 水溶性离子 PM2.5 北京 相关性 季节变化 |
| 英文关键词 water-soluble ions PM2.5 Beijing correlation seasonal variation |
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| 中文摘要 |
| 2012年8月~2013年7月,在北京市包括城市背景、城区、郊区以及边界传输点在内的9个监测点位进行大气细颗粒物PM2.5样品的采集与分析,共获得486个有效样本及9种水溶性离子的质量浓度. 观测期间9种水溶性离子总质量浓度为60.5 μg·m-3,浓度水平高低顺序分别为NO3->SO42->NH4+->Cl->Na+>K+>Ca2+>F->Mg2+; 其中SO42-、NO3-和NH4+(三者简称SNA)占全部所测水溶性离子的88%; NO3-是全年波动范围最大的二次离子. 对所测阴、阳离子相关性研究发现,阴、阳离子总体相关性良好,春、冬季阴、阳离子相关性要好于夏、秋季. 对不同颗粒质量级别中的水溶性离子研究发现,SNA积累活跃,相对于SO42-的积累,NO3-和NH4+在二次离子的形成过程中占据主导地位; NO3-是重污染过程累积效应比较明显且贡献相对较高的二次离子. |
| 英文摘要 |
| A total of 486 daily PM2.5 samples were collected at a background site, 3 urban sites, 4 suburban sites and a boundary transfer site during August 2012-July 2013. Mass concentrations of 9 water-soluble ions were obtained. The average mass concentration of the 9 ions was 60.5 μg·m-3, and the order of concentration of ions was NO3->SO42->NH4+->Cl->Na+>K+>Ca2+>F->Mg2+; Secondary inorganic species NO3-, SO42- and NH4+ were the major components of water-soluble ions in PM2.5, with a contribution of 88% to the total ions of PM2.5. NO3- was the most fluctuated anion during the sampling period. With the increase of pollution level, the accumulation of SNA was obvious, the components that contained nitrogen, NO3- and NH4+, occupied the dominant position in the formation of the secondary components. NO3- had a relatively higher contribution to the accumulation of heavy pollution. |
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