北京市大气VOCs的时空分布特征及化学反应活性

发布时间：2018-02-10 08:47

本文关键词： 北京挥发性有机物时空分布化学反应活性　出处：《中国环境科学》2017年10期 　论文类型：期刊论文

【摘要】：2014年在北京市城市对照点定陵(城市背景点)、东四(城区点)和永乐店(东南区域传输点)3个不同功能站点进行了为期一年的大气挥发性有机物连续自动观测,测定了包括含氧VOCs在内的98种挥发性有机物,系统分析了北京地区大气VOCs的组成特征、时空分布特征及大气化学活性.结果表明,北京市大气VOCs的年均体积分数为(47.36±13.78)×10-9,化学组成以烷烃为主,占39.55%,其次是OVOCs,再次是烯烃和芳香烃.中心城区点和东南区域传输点的VOCs浓度水平显著高于城市背景点.中心城区点VOCs受交通源和生活燃气排放影响显著,东南区域传输点受交通源和工业溶剂源影响显著,而城市背景点则受上风城区传输影响大.总VOCs浓度季节变化整体表现为冬高、夏低的特点.受污染来源的差异影响,不同点位的不同组分表现出并不相同的日变化特征.甲苯/苯的比值分析显示,北京地区冬季采暖期燃煤影响突出,春夏季溶剂挥发贡献增加.北京VOCs大气化学活性以烯烃为主,其次是芳香烃和OVOCs,关键活性组分有乙烯、乙醛、间/对-二甲苯、甲苯、丙烯、邻-二甲苯、乙苯、正丁烷、1-丁烯和丙醛等.
[Abstract]:In 2014, continuous automatic observation of atmospheric volatile organic compounds (VOC) was carried out at three different functional stations of Dingling (urban background point), Dongsi (urban area) and Yonglidian (southeastern transmission point) in Beijing. 98 volatile organic compounds, including oxygen-containing VOCs, were determined. The composition, space-time distribution and atmospheric chemical activity of atmospheric VOCs in Beijing were systematically analyzed. The average annual volume fraction of atmospheric VOCs in Beijing is 47.36 卤13.78 脳 10 ~ (-9). The VOCs concentration of the central urban area and the southeastern transport point was significantly higher than that of the urban background point. The VOCs in the central urban area was significantly affected by traffic sources and domestic gas emissions. The transport sites in the southeast region were significantly affected by traffic sources and industrial solvent sources, while the urban background points were greatly affected by the transport in the upper urban areas. The seasonal variation of total VOCs concentrations was characterized by winter high and summer low, and affected by the difference of pollution sources. The analysis of toluene / benzene ratio shows that the influence of coal burning during the winter heating period in Beijing area is obvious. In spring and summer, the contribution of solvent volatilization was increased. The atmospheric chemical activity of VOCs in Beijing was mainly olefin, followed by aromatic hydrocarbons and OVOCs. The key active components were ethylene, acetaldehyde, m-p-xylene, toluene, propylene, o-xylene, ethylbenzene. N-butane 1-butene and allaldehyde, etc.
【作者单位】：北京市环境保护监测中心;大气颗粒物监测技术北京市重点实验室;北京市环境保护局;
【基金】：环保公益性行业科研专项(201409005) 国家重点研发计划课题(2016YFC0208500,2016YFC0208502)
【分类号】：X51

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