西安市采暖季过渡期高时间分辨率细颗粒物组分特征及来源解析  

Components Characteristic and Source Apportionment of Fine Particulate Matter in Transition Period of Heating Season in Xi'an with High Time Resolution

作　　者：李萌津 张勇[2] 张倩 田杰[2,3] 李丽 刘卉昆 冉伟康 王启元 LI Meng-jin;ZHANG Yong;ZHANG Qian;TIAN Jie;LI Li;LIU Hui-kun;RAN Wei-kang;WANG Qi-yuan(School of Environmental and Municipal Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;Institute of Earth Environment,Chinese Academy of Sciences,Xi'an 710061,China;National Observation and Research Station of Regional Ecological Environmental Change and Comprehensive Management in the Guanzhong Plain,Xi'an 710061,China)

机构地区：[1]西安建筑科技大学环境与市政工程学院,西安710055 [2]中国科学院地球环境研究所,西安710061 [3]陕西关中平原区域生态环境变化与综合治理国家野外科学观测研究站,西安710061

出　　处：《环境科学》2024年第5期2571-2580,共10页Environmental Science

基　　金：国家重点研发计划项目(2022YFF0802501);陕西省自然科学基础研究计划项目(2023-JC-JQ-23);陕西省自然科学基础研究计划项目(2022JQ-267);陕西省重点研发计划项目(2022ZDLSF06-07)。

摘　　要：受到供暖影响,北方城市秋冬季的大气细颗粒物(PM_(2.5))浓度升高,空气污染加剧.利用气溶胶化学组分监测仪、七波段黑碳仪以及大气多金属元素在线监测仪于2019年10月25日至11月17日在西安市开展高时间分辨率PM_(2.5)化学组分在线监测,分析采暖季过渡期PM_(2.5)污染特征,同时结合正定矩阵因子分解模型解析PM_(2.5)来源.结果表明,观测期间ρ(PM_(2.5))平均值为(78.3±38.5)μg·m^(−3),主要化学组分为有机物(OA)、二次无机离子(SIA)和粉尘,其占比分别为38.7%、31.6%和21.2%,其中ρ(SO_(4)^(2-))、ρ(NO_(3)^(-))和ρ(NH_(4)^(+))平均值分别为(4.0±3.1)、(14.9±13.7)和(5.8±4.8)μg·m^(−3),主要金属ρ(K)、ρ(Ca)和ρ(Fe)平均值分别为(1.0±0.4)、(1.5±1.1)和(1.4±0.9)μg·m^(−3),BC(贡献率为5.7%)、Cl^(-)(贡献率为1.3%)及微量元素(贡献率为1.5%)对PM_(2.5)的贡献率相对较低.在污染发展和维持阶段,OA和SIA浓度的增加幅度可达137.7%~537.0%,在污染消散阶段则仅有粉尘浓度呈增长之势.来源解析结果显示二次源、生物质燃烧源、扬尘源、机动车源、工业源和燃煤源是观测期间PM_(2.5)的主要来源,分别贡献了29.1%、21.1%、15.3%、12.9%、11.4%和10.2%,其中二次源和生物质燃烧源在污染发展和维持阶段贡献率较高,扬尘源在污染消散阶段贡献率较高.Influenced by heating,the concentration of atmospheric fine particulate matter(PM_(2.5))rises in autumn and winter in northern cities.In this study,Q-ACSM,AE33,and Xact 625 were used to carry out online monitoring of PM_(2.5) chemical components with high time resolution in Xi'an from October 25 to November 17,2019,to analyze the characteristics of PM_(2.5) pollution during the transition period of the heating season.Additionally,we analyzed the sources of PM_(2.5) in combination with the positive matrix factorization model.The results showed that the average PM_(2.5) concentration during the observation period was(78.3±38.5)μg·m^(−3),and the main chemical components were organic matter(OA),secondary inorganic ions(SIA),and dust,which accounted for 38.7%,31.6%,and 21.2%,respectively.The average concentrations of sulfate,nitrate,and ammonium were(4.0±3.1),(14.9±13.7),and(5.8±4.8)μg·m^(−3),and the average concentrations of the major metals potassium,calcium,and iron were(1.0±0.4),(1.5±1.1),and(1.4±0.9)μg·m^(−3).Black carbon,chloride ions,and trace elements contributed relatively little to PM_(2.5)(5.7%,1.3%,and 1.5%,respectively).In the pollution development and maintenance stage,the concentration of OA and SIA increased by 137.7%to 537.0%,whereas in the pollution dissipation stage,only the concentration of dust gradually increased.The source apportionment results showed that secondary sources,biomass burning,dust,vehicle emission,industrial emission,and coal combustion were the main sources of PM_(2.5) during the observation period,contributing 29.1%,21.1%,15.3%,12.9%,11.4%,and 10.2%,respectively.The contribution rate of secondary sources and biomass burning was higher in the pollution development and maintenance stage,and dust was higher in the pollution dissipation stage.

关 键 词：大气细颗粒物 组分特征 形成机制 来源解析 污染成因 

分 类 号：X513[环境科学与工程—环境工程]