2016年太原市空气PM2.5中重金属元素来源分析

Analysis on source of heavy metal elements in PM2.5,Taiyuan city,2016

目的了解太原市空气细颗粒物(PM2.5)中重金属元素构成及其来源。方法 2016年在太原市中心城区位置设置空气监测点,全年每个月连续采集为期一周(11~16日)的空气PM2.5,采用电感耦合等离子体质谱法(ICP-MS)分析PM2.5中12种元素的质量浓度,采用因子分析法对各重金属元素的来源进行解析。结果采暖期PM2.5重金属元素浓度明显大于非采暖期。燃煤、钢铁冶金和机械重工工业是PM2.5的主要来源,贡献率为>40.00%,采暖与非采暖季贡献率稳定(分别为44.61%和42.96%)。机动车排放污染和沙尘、地面扬尘、水泥尘是另外两个重要来源,但前者采暖季贡献率较大(采暖期贡献率为30.83%、非采暖期贡献率为16.57%),而后者非采暖期贡献率较大(采暖期贡献率为11.29%、非采暖期贡献率为22.09%)。结论燃煤、钢铁冶金和机械工业是太原市PM2.5的首要来源,机动车排放次之。

Objective To understand the composition and sources of heavy metal elements in ambient fine particulate matter（PM2.5） in Taiyuan city. Methods An air monitoring site was set in the central area of Taiyuan eity,2016,the ambient PM2.5samples were collected from llth to 16th every month, 12 heavy metal elements（Be, Cd, Pb, Mn, Se, TI, Sb, Al, As, Cr, Hg and Ni） were analyzed through ICP MS. Factor analysis was conducted for PM2.5 source evaluation. Results Most of the heavy metal elements had higher concentrations during the heating season. Coal combustion, ferrous metallurgy industrial emission and mechanical heavy industries were the main sources of the ambient PM2.5, which contributed to over 40.00% of the total. The contribution rate was stable in the heating and non-heating seasons （44.61 and 42.96 ~//00,respectively）. Motor vehicle emissions,sand dust,ground dust and cement dust pollution were the other two important sources,but the contribution rate of the former in the heating season was bigger （that of the heating season accounted for 30.83% ,and that of the non-heating season accounted for 16.57%） ,while that of the latter was bigger in the non-heating season （that of the heating season accounted for 1 1.29%, and that of the non-heating season accounted for 22.09%）. Conclusion Coal combustion,ferrous metallurgy industry and mechanical industry are the dominant sources of ambient PM2.5 pollution in Taiyuan city,followed by vehicle emissions.