2019—2021年徐州市大气细颗粒物化学组成特征及来源解析  

Chemical Composition Characteristics and Analysis of PM_(2.5) in Xuzhou from 2019 to 2021

作　　者：饶永才 冯春莉 邓国庆 孙瑞 李辉 孟庆江 郁建桥[2] RAO Yongcai;FENG Chunli;DENG Guoqing;SUN Rui;LI Hui;MENG Qingjiang;YU Jianqiao(Xuzhou Environmental Monitoring Center,Xuzhou 221000,China;Jiangsu Provincial Environmental Monitoring Center,Nanjing 210019,China)

机构地区：[1]江苏省徐州环境监测中心,江苏徐州221000 [2]江苏省环境监测中心,江苏南京210019

出　　处：《中国环境监测》2023年第2期158-168,共11页Environmental Monitoring in China

基　　金：徐州市重点研发计划项目(社会发展KC20057)。

摘　　要：徐州市地处四省交界,大气污染物来源复杂,颗粒物污染在气象条件不利时较为显著。通过地面观测数据、颗粒物组分连续观测、源解析及轨迹溯源等方法,对徐州市2019—2021年颗粒物变化特征进行了全面分析,以定量解析各类污染源的贡献,识别对颗粒物贡献显著的化学成分。结果表明:PM2.5各组分质量占比中二次无机盐和有机碳相对较高,其中二次无机盐SNA(SO^(2-)_(4),NO^(-)_(3),NH^(+)_(4))占比达到59.1%~62.7%;水溶性离子总浓度逐年降低,但Mg^(2+)和Ca^(2+)浓度2021年分别同比增加2%和12.5%,说明扬尘污染存在反弹。秋冬季水溶性离子明显较高,Cl-浓度明显高于其他季节,表明徐州市秋冬季受移动源、燃煤源和二次有机气溶胶共同影响。PM_(2.5)中OC与EC质量浓度比为4.88~8.40,说明徐州市颗粒物受多源影响,柴油、汽油机动车尾气排放以及燃煤排放对颗粒物贡献较大。后向轨迹分析表明,污染严重的1月污染物主要来自4个方向,其中来自苏北和鲁南的2条轨迹气团出现频率最高,分别为34.36%和29.21%,PM2.5质量浓度分别为100μg/m^(3)和106μg/m^(3),不同方向轨迹的组分具有较大不同。Xuzhou is located at the border of four provinces,and the sources of its air pollutants are complex.Particulate pollution will be more significant when the meteorological conditions are unfavorable.Ground observation data,continuous observation of particulate components,source apportionment analysis and trajectory analysis were used to comprehensively analyze the characteristics of particulate matter in Xuzhou in recent three years,with the objective to quantitatively analyze the contributions of various pollution sources and identify the chemical components that contribute significantly to particulate matter.The results showed that:The mass proportion of secondary inorganic salts and organic carbon components(OC)in PM2.5 was relatively high,and the proportion of secondary inorganic salts SNA(SO^(2-)_(4),NO^(-)_(3),NH^(+)_(4))was 59.1%-62.7%.The total concentration of watersoluble ions decreased year by year,but the concentration of Mg^(2+)and Ca^(2+)increased by 2%and 12.5%in 2021,respectively,indicating a rebound in dust pollution.The water-soluble ions were significantly higher in autumn and winter,and the concentration of Cl-was significantly higher than that in other seasons,indicating that mobile sources,coal-burning sources and secondary organic aerosols had a combined influence in autumn and winter in Xuzhou.The OC/EC ratio of PM_(2.5)was between 4.88-8.40,which indicated that particulate matter in Xuzhou was affected by multiple sources.In specific,diesel and gasoline vehicle exhaust emissions and coal burning emissions contributed significantly to particulate matter.The backward trajectory analysis showed that the pollutants with heavy pollution in January mainly came from four directions.The air mass from northern Jiangsu and southern Shandong had the highest frequency,which was 34.36%and 29.21%,respectively.The corresponding PM2.5 concentration was 100μg/m^(3) and 106μg/m^(3),respectively.

关 键 词：PM_(2.5) 颗粒物组分 源解析 后向轨迹 区域传输 

分 类 号：X51[环境科学与工程—环境工程] X823