| 兰州大气细颗粒物中多环芳烃污染特征及来源分析 |
| 摘要点击 3206 全文点击 1413 投稿时间：2015-10-11 修订日期：2016-02-28 |
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| 中文关键词 兰州 PM2.5 PAHs 季节变化 来源分析 |
| 英文关键词 Lanzhou PM2.5 PAHs seasonal variation source apportionment |
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| 中文摘要 |
| 多环芳烃(polycyclic aromatic hydrocarbons, PAHs)是环境空气中一类重要的有毒化合物,为探究兰州市大气细颗粒物(fine particulate matter, PM2.5)中PAHs的污染特征,于2012年冬季和2013年夏季采集兰州市PM2.5样品共60个,并进行了GC/MS分析.结果表明,16种PAHs的冬、夏季平均总质量浓度分别为(191.79±88.29)ng·m-3和(8.94±4.34)ng·m-3,冬季污染程度明显严重;降雪是导致兰州冬季大气PM2.5中PAHs质量浓度降低最主要的气象因素;冬、夏季PAHs的环数分布均以4环比例最大,分别为51.40%和49.94%,5~6环比例夏季41.04%,高于冬季24.94%,2~3环比例冬季23.67%,高于夏季9.03%;通过PAHs的特征比值分析,兰州大气PM2.5中PAHs的来源冬季以燃煤源和机动车尾气为主,其中柴油车比例较大;夏季汽油车对PAHs的相对贡献较大. |
| 英文摘要 |
| Polycyclic aromatic hydrocarbons (PAHs) are a group of important toxic compounds. In order to detect the pollutional characteristics of atmospheric PAHs in Fine Particulate Matter (PM2.5), a total of 60 PM2.5 samples were collected in Lanzhou City during the winter of 2012 and summer of 2013. The GC/MS measurement results of the samples demonstrated the averagely total mass concentrations of the most significant 16 homologues of PAHs were (191.79±88.29) ng·m-3 and (8.94±4.34) ng·m-3 in winter and summer respectively, indicating a higher pollution level in winter. In winter, the snowfall was the most important meteorological factor for the decrease of PAHs mass concentration in PM2.5. The percentages of PAHs with 4 rings were the highest in both winter (51.40%) and summer (49.94%) in Lanzhou. The percentage of PAHs with 5-6 rings in summer (41.04%) was higher than that in winter (24.94%). However, the percentage of PAHs with 2-3 rings in summer (9.03%) was lower than that in winter (23.67%). Based on the analysis of characteristic ratios, we concluded that the PAHs in atmospheric PM2.5 in Lanzhou were mainly sourced from coal and vehicle emissions in winter, especially the diesel vehicles. The absolute contributions of all possible PAHs pollution sources were insignificant in summer, with relatively higher contribution from gasoline vehicles. |
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