| 降雪后24 h内大气中多环芳烃的变化规律 |
| 摘要点击 2419 全文点击 681 投稿时间：2020-08-06 修订日期：2020-09-09 |
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| 中文关键词 多环芳烃(PAHs) 大气 降雪 污染特征 变化规律 |
| 英文关键词 polycyclic aromatic hydrocarbons (PAHs) atmosphere snowfall pollution characteristic temporal trend |
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| 中文摘要 |
| 大气是挥发性和半挥发性污染物迁移扩散的重要介质，也是污染物进入人体的主要途径，因此，大气中污染物的环境行为的研究具有重要的意义.本研究通过采集雪样和降雪后连续24 h内的大气样品，对16种多环芳烃（PAHs）进行了分析，对降雪后大气中PAHs的变化规律进行了深入研究.结果表明，16种PAHs在降雪中的检出率为100%，菲的浓度最高（538.3 ng·L-1），其次是萘（509.1 ng·L-1）和荧蒽（429.9 ng·L-1），说明降雪能够对大气中的PAHs进行去除.降雪后大气中PAHs的浓度呈现下降-上升-下降的变化规律，高浓度出现在汽车尾气排放量最大的上下班期间，低浓度则出现在人类活动少的时间段，说明人类活动是大气中PAHs浓度变化的主要影响因素.降雪后24 h内大气中PAHs在气相和颗粒相间的比值变化较小，其组成主要受PAHs的物理化学性质的影响.特征分子比值法表明，降雪后24 h内大气中PAHs主要来源于固体燃料燃烧源和液体燃料的燃烧源. |
| 英文摘要 |
| The atmosphere is a significant medium for the transportation and diffusion of volatile and semi-volatile pollutants. Furthermore, the atmosphere is the primary exposure route for pollutants to enter the human body. Therefore, the study of the environmental fate of pollutants in the atmosphere is essential. In this study, 16 polycyclic aromatic hydrocarbons (PAHs) were analyzed in snow samples and air samples within 24 hours after a snowfall, and the temporal trend of PAHs in the atmosphere was comprehensively studied. The results indicated that the detection rate of the 16 PAHs in snow was 100%, and the concentration of phenanthrene (538.3 ng·L-1) was the highest, followed by naphthalene (509.1 ng·L-1) and fluoranthene (429.9 ng·L-1), indicating that snowfall can remove PAHs from the atmosphere. After the snowfall, a falling-rising-falling temporal trend of the concentrations of PAHs in the atmosphere was observed. Higher concentrations appeared during rush hour, with the largest automobile exhaust emissions, while lower concentrations appeared during periods with the lowest human activity. The results indicated that the atmospheric concentrations of PAHs were predominantly influenced by human activities. Within 24 hours after snowfall, the ratio of PAHs between the gas phase and particle phase, which depends primarily on the physical and chemical properties of PAHs, had not changed substantially. The diagnostic ratios indicated that within 24 hours after snowfall, the PAHs in the atmosphere originated mostly from the emissions of solid fuel and liquid fuel combustion. |
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