武汉市居民区大气VOCs的污染特征和来源解析

于2016年7月-2017年6月在武汉市典型居民区对大气中101种挥发性有机物（VOCs）进行了监测，以便研究武汉市典型居民区周边VOCs的组成特征和变化规律，并探讨了其主要来源.结果表明，武汉市空气中VOCs的体积分数为（46.24±24.57）×10^-9，表现为烷烃>含氧有机物>烯烃>卤代烃>芳香烃.受交通排放影响烷烃的比例上午高于下午，1月机动车尾气为武汉市主要的VOCs排放源，夏季含氧类化合物浓度高于冬季，可能更多地受本地喷涂等溶剂使用行业和光化学反应生成的影响，5-9月表现出明显的生物源排放特征.利用正交矩阵因子分析（PMF）得到武汉市居民区大气VOCs主要有6个来源，分别为燃烧源、机动车尾气、工业排放、溶剂使用、汽油挥发和植物排放.其中，燃烧源、机动车尾气贡献比例最高，是该区域VOCs控制的重要排放源.

Pollution characteristics and source apportionment of VOCs in ambient air of a residential area in Wuhan

Ambient volatile organic compounds (VOCs) were collected from July 2016 to June 2017 at a residential site in Wuhan.The characteristics and source apportionment were studied.The results showed that the total concentration of VOCs was (46.24±24.57)×10^-9;the concentration of alkanes was largest,followed by oxygenated VOCs,olefins,halogenated hydrocarbons,and aromatic hydrocarbons.Affected by motor vehicle exhaust,the ratio of alkanes was higher in the morning than in the afternoon.Vehicular exhaust was the major source in January,and the concentrations of VOCs in summer were higher than those in winter because of local coating solvents used for the chemical industry and photochemical reactions.The characteristics of biogenic emissions were clear from May to September.The positive matrix factorization model was used to investigate sources of VOCs in a residential area of Wuhan,and six factors were resolved,including combustion sources,vehicle exhaust,industrial processes,solvent use,gasoline volatilization,and biogenic sources.The contribution rate of combustion sources and vehicle exhaust was highest,which were important sources of controlled VOC emissions in the region.