镇江市丹徒区大气PM_(2.5)无机元素、水溶性离子污染特征及来源

Pollution characteristics and source of inorganic elements and water soluble ions in PM_(2.5) in Dantu District of Zhenjiang City

目的探讨镇江市丹徒区PM_(2.5)中无机元素、水溶性离子的污染特征及来源。方法 2016年3月—2017年2月期间在镇江市丹徒区进行PM_(2.5)采样,分析PM_(2.5)、3种水溶性阴离子及11种无机元素的质量浓度。结果 PM_(2.5)平均浓度为69.82μg/m^3(6.29~162.38μg/m^3),超标率为34.9%;水溶性离子质量浓度的总均值为25.36μg/m^3(2.82~65.90μg/m^3),其中NO_3^-、SO_4^(2-)的浓度在10.00μg/m^3以上;无机元素质量浓度的总均值为224.20 ng/m^3(46.30~1 553.11 ng/m^3),Al、Pb、Mn的浓度在40.00 ng/m^3以上。结论 NO_3^-、SO_4^(2-)是主要的水溶性离子组成,主要无机元素为Al、Pb和Mn。水溶性离子及无机元素浓度存在季节性变化,均呈现冬春季节高于夏秋季的现象,富集因子结果表明除Al外的10种无机元素高度富集于PM_(2.5)上且主要来源于人为污染。主成分分析结果表明,PM_(2.5)有4组主要的污染来源,分别为煤炭燃烧和交通排放混合源、二次气溶胶以及工业排放源。

[Objective]To explore the pollution characteristics and source of inorganic elements and water soluble ions in PM2.5 in Dantu District of Zhenjiang City.[Methods]Atmospheric PM2.5 samples were collected from March 2016 to February 2017 in this area,to analyze the mass concentration of PM2.5,11 kinds of inorganic elements and 3 kinds of water-soluble ions.[Results]The results showed that the average mass concentration of PM2.5 during the sampling period was 69.82 μg/m^3（6.29-162.38 μg/m^3）and the exceeding criteria rate was 34.9%. The total average of water-soluble ion concentration was 25.36 μg/m^3（2.82-65.90 μg/m^3）,while mass concentrations of NO_3^- and SO_4^（2-） were over 10 μg/m^3. The mean concentration of total inorganic elements was224.20 ng/m^3（46.30-1 553.11 ng/m^3）,and the concentrations Al,Pb and Mn were higher than 40.00 ng/m^3.[Conclusion]NO_3^- and SO_4^（2-） are the main water-soluble ions and inorganic elements are Al,Pb and Mn. The concentrations of water-soluble ions and inorganic elements appeared seasonal variation,and there is the phenomenon that concentrations of these components in winter and spring are higher than those in summer and autumn. The results of enrichment factor analysis shows that 10 kinds of inorganic elements（except Al）are highly gathered in PM2.5 and polluted by anthropogenic factor. The results of principle component analysis show that that the sources of PM2.5 mainly arise from traffic emission,coal combustion,secondary aerosols and industrial emissions.