长沙夏季大气非甲烷碳氢污染特征及来源解析  

Pollution characteristics and sources apportionments of ambient nonmethane hydrocarbons during summer in Changsha

作　　者：邹利林 张洲[1,2] 蒋利华[3] 王真真[3] 姚运先[3] 黄忠辉 张艳利[2] 王新明[2] ZOU Lilin;ZHANG Zhou;JIANG Lihua;WANG Zhenzhen;YAO Yunxian;HUANG Zhonghui;ZHANG Yanli;WANG Xinming(Changsha Center for Mineral Resources Exploration,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Changsha,410013,China;State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou,510640,China;Hunan Provincial Environment Protection Engineering Center of Atmospheric Volatile Organic Compounds Monitoring and Control Technology,Changsha Environmental Protection College,Changsha,410004,China;South China Institute of Environmental Sciences,Ministry of Ecology and Environment,Guangzhou,510655,China)

机构地区：[1]中国科学院广州地球化学研究所长沙矿产资源勘查中心,长沙410013 [2]中国科学院广州地球化学研究所,有机地球化学国家重点实验室和广东省环境资源利用与保护重点实验室,广州510640 [3]长沙环境保护职业技术学院,湖南省环境保护大气挥发性有机污染物监测与控制工程技术中心,长沙410004 [4]生态环境部华南环境科学研究所,广州510655

出　　处：《环境化学》2024年第2期578-589,共12页Environmental Chemistry

基　　金：中国科学院战略性先导科技专项(XDA23010303);湖南省环保科研课题(2021[湘财预]0001号);广东省基础与应用基础研究基金项目(2021A1515110387);广州市科技计划项目(202102020315)资助。

摘　　要：非甲烷碳氢(NMHCs)是臭氧等二次污染重要前体物.选择长沙市2个城市站(W和S点)于2017年夏季采集了大气NMHCs样品.结果显示,观测期间长沙市NMHCs平均体积浓度为(8.67±3.62)×10^(-9)(W)和(12.30±6.01)×10^(-9)(S).烷烃是最主要组分,贡献了64.7%(W)和60.5%(S);其次是芳香烃,占比21.6%(W)和24.4%(S).浓度组成及比值日变化特征表明W点NMHCs浓度上午高于下午,主要受机动车排放影响;S点则是早晚高中午低,可能与中午光化学反应强、早高峰机动车排放大等有关.芳香烃是最重要的活性化合物,贡献了53.9%—56.0%的臭氧生成潜势;异戊二烯和烯烃对等效丙烯浓度的贡献也较大(合计>40%).长沙市夏季大气NMHCs来源主要有汽油车尾气(25.0%)、工业过程与溶剂使用(20.2%)、生物质燃烧与天然气使用(19.8%)、汽油挥发(17.2%)、柴油车尾气(12.3%)和植物排放(5.5%).不同站点来源存在差异:W点受汽油车尾气影响最大(30.2%),其次是生物质燃烧与天然气使用(22.6%);而S点主要受工业过程与溶剂使用(23.9%)和汽油车尾气影响(20.2%).Non-methane hydrocarbons(NMHCs)are important precursors of ozone and other secondary pollutants.Ambient NMHCs samples were collected at two urban sites(W and S)during summer of 2017 in Changsha.The results showed that average volume concentrations of NMHCs were(8.67±3.62)×10^(-9) and(12.30±6.01)×10^(-9) at Site W and Site S,respectively.Alkanes were the most abundant components with contributions of 64.7%(W)and 60.5%(S),followed by aromatics with percentages of 21.6%(W)and 24.4%(S),respectively.The diurnal variations of NMHCs concentrations,compositions and diagnostic ratios illustrated that NMHCs concentrations were higher in the forenoon than those in the afternoon at Site W,which were mainly influenced by vehicle emissions;while,concentrations at Site S were higher in morning and evening but lower in noon,which were probably influenced by strong photochemical reactivity in noon and enhanced vehicle emissions in morning.Aromatics were the most important reactive species and contributed 53.9%—56.0%to ozone formation potentials,while isoprene and alkenes were also contributed largely to propylene-equivalent concentrations(>40%).The main sources of NMHCs in summer air of Changsha were gasoline vehicle exhaust(25.0%),industrial process and solvent use(20.2%),biomass burning and natural gas usage(19.8%),gasoline evaporation(17.2%),diesel vehicle exhaust(12.3%),and plant emission(5.5%).Spatial difference showed that the largest source at Site W was gasoline vehicle exhaust(30.2%),followed by biomass burning and natural gas usage(22.6%),while NMHCs at Site S were mainly influenced by industrial process and solvent use(23.9%)and gasoline vehicle exhaust(20.2%).

关 键 词：非甲烷碳氢 污染特征 来源解析 光化学活性 长沙 

分 类 号：X51[环境科学与工程—环境工程]