长三角背景大气PM_(2.5)中非极性有机化合物组成特征及来源  

Composition Characteristics and Sources of Non-polar Organic Compounds in PM_(2.5) in the Background Atmosphere of Yangtze River Delta

作　　者：吴长流 曹芳 贾小芳[3] 张煜娴 谢添 任磊 章炎麟 WU Chang-liu;CAO Fang;JIA Xiao-fang;ZHANG Yu-xian;XIE Tian;REN Lei;ZHANG Yan-lin(International Joint Laboratory on Climate and Environment Change(ILCEC),Yale-NUIST Center on Atmospheric Environment,School of Applied Meteorology,Nanjing University of Information Science&Technology,Nanjing 210044,China;School of Applied Meteorology,Nanjing University of Information Science&Technology,Nanjing 210044,China;Meteorological Observation Center of Chinese Meteorological Administration,Beijing 100081,China)

机构地区：[1]南京信息工程大学应用气象学院,耶鲁大学-南京信息工程大学大气环境中心,气候与环境变化国际合作联合实验室,南京210044 [2]南京信息工程大学应用气象学院,南京210044 [3]中国气象局气象探测中心,北京100081

出　　处：《环境科学》2023年第2期646-657,共12页Environmental Science

基　　金：国家自然科学基金项目(41977185,41977305);江苏省“333人才工程”项目(BRA2020068)。

摘　　要：为了探究长三角区域大气细颗粒物中非极性有机化合物的组成及来源特征,于2019年12月至2020年11月在临安区域大气本底站采集了129个PM_(2.5)样品,对其有机碳(OC)、元素碳(EC)和非极性有机化合物(NPOCs,包括多环芳烃、正构烷烃和藿烷类)进行了分析,并用分子示踪物、特征比值和正定矩阵因子分析模型等方法探究了有机气溶胶的主要来源.结果表明,临安ρ(PM_(2.5))的年平均值约为(32.36±20.44)μg·m^(-3),ρ(NPOCs)年平均值约为(59.05±40.39)ng·m^(-3),呈现出冬高夏低的季节变化特征.正构烷烃主要源于化石燃料和生物质(草和木材等)燃烧等人为源,其次为高等植物角质层蜡排放;多环芳烃主要源于燃煤燃烧、机动车排放和生物质燃烧等非化石源的混合贡献;藿烷类物质主要源于机动车排放,其中冬季还受到燃煤源的影响.后向轨迹聚类分析和潜在源区分析表明临安主要受到外来气团输送的影响.结合正定矩阵因子分析模型对采样期间观测到的NPOCs进行源解析,得到了燃煤燃烧源、交通排放源和生物质燃烧等非化石源:冬季以交通源为主,贡献率为59%;春、夏季以燃煤源为主,贡献率分别为58%和57%;秋季以生物质燃烧等非化石源为主,贡献率为64%.In order to explore the composition and source characteristics of non-polar organic compounds(NPOCs) in atmospheric fine particulate matter in the Yangtze River Delta region,129 PM_(2.5) samples were collected at the Regional Atmospheric background station in Lin’an from December 2019 to November 2020.Including polycyclic aromatic hydrocarbons(PAHs),n-alkanes,and hopanes,the main sources of organic aerosols were investigated using molecular tracers,eigen ratios,and orthogonal matrix factorization models.The results showed that the average annual mass concentration of PM_(2.5) in Lin’an was approximately(32.36±20.44) μg·m^(-3),and the average annual mass concentration of NPOCs was approximately(59.05±40.39) ng·m^(-3),showing the seasonal characteristics of being high in winter and low in summer.n-alkanes mainly came from fossil fuels and biomass(grass,wood,etc.) burning,followed by cuticle wax emission from higher plants.PAHs mainly came from the mixed contribution of non-fossil sources such as coal burning motor vehicle emissions and biomass combustion.Hopanes were mainly derived from motor vehicle emissions,which were also affected by coal burning in winter.Backward trajectory cluster analysis and potential source analysis showed that Lin’an was mainly affected by external air mass transport.Combined with the orthogonal matrix-factor decomposition model,NPOCs observed during the sampling period were analyzed,and non-fossil sources such as coal burning sources,transportation emission sources,and biomass combustion were obtained.In winter,transportation sources were the main source,accounting for 59%.In spring and summer,coal burning was the main source,accounting for 58% and 57%,respectively.In autumn,biomass combustion and other non-fossil sources dominated,accounting for 64%.

关 键 词：长三角地区 背景大气 非极性有机化合物 PMF模型 源解析 

分 类 号：X513[环境科学与工程—环境工程]