基于PMF和APCS-MLR模型的工业城市大气降尘金属源解析及综合污染评价

为研究邯郸市区大气降尘的污染状况，在3个功能区逐月采集了2年的大气降尘样品，分析了降尘中Al、Fe、Cd、Cr、Cu、Mn、Ni、Pb、Zn和As等10种金属元素的质量分数，使用正定矩阵因子分解模型(PMF)和绝对主成分-多元线性回归模型(APCS-MLR)解析其来源，并采用大气降尘重金属综合污染指数(IPI.dhm)模型评估8种重金属(Cd、Cr、Cu、Mn、Ni、Pb、Zn和As)的污染水平，并结合最优源解析结果定量计算各源的污染贡献。结果表明：除Al外，邯郸市大气降尘中9种金属元素质量分数均超过河北省(A层)土壤背景值，不同功能区元素含量差异明显；PMF模型解析出5个源，分别为燃煤源、冶炼排放源、自然源、道路交通源和工业排放源；APCS-MLR解析出3个源，分别是工业与冶炼排放源，燃煤和交通混合源及自然源；PMF的解析结果更优。IPI.dhm结果显示，Cd、Cr、Zn和Pb为显著污染因子。基于源贡献的污染评估结果表明，5个源的贡献率依次为工业排放源(32.81%)>燃煤源(21.73%)>冶炼排放源(16.80%)>道路交通源(15.02%)>自然源(13.63%)。以上结果表明，该地区大气降尘重金属污染主要受工业和燃煤排放影响，建议优先控制工业排放和推进清洁能源以控制区域降尘重金属污染。本研究用到的大气降尘污染的来源解析与综合污染评价方法可为其他工业城市的提供参考。

Source apportionment of metals in atmospheric deposition of a typical industrial city based on PMF and APCS-MLR and comprehensive pollution assessment

In order to study the pollution situation of atmospheric deposition in Handan urban area, 3 sampling sites were set and 72 atmospheric deposition samples had been collected monthly from December 2017 to November 2019 by atmospheric dry and wet deposition autosampler. Contents of 10 metals (Al, Fe, Cd, Cr, Cu, Mn, Ni, Pb, Zn and As) in the atmospheric deposition samples were measured. The sources of metals were identified by positive matrix factorization model (PMF) and absolute principal component score-multiple linear regression receptor modeling (APCS-MLR). The results of two receptor models were compared. The pollution level of 8 heavy metals was assessed by the integrated pollution index of the dust heavy metal (IPI.dhm) model. The pollution contributions of each source were quantitatively calculated in combination with the source apportionment results of more suitable model. Results showed that except for Al, all 9 metals in the atmospheric deposition exceeded the corresponding soil background values for Hebei Province (A layer). 5 sources of metals in the atmospheric deposition were identified by PMF model: source, smelting emission source, natural source, transportation source and industrial emission source. 3 factors were identified by APCS-MLR: industrial smelter emission source, natural source, coal-burning and transportation mixed source. Better results of PMF were observed in this study. PMF were better than APCS-MLR. The result of IPI.dhm model showed that Cd, Cr, Zn and Pb were the significant pollution factors. Based on the pollution assessment result of source apportionment, the pollution contribution rates of the 5 sources were in order of industrial emission source (32.81%) > coal-burning source (21.73%) > smelting emission source (16.80%) > transportation source (15.02%) > natural source (13.63%). The study showed that the heavy metal pollution of atmospheric deposition in Handan urban area was mainly affected by industrial and coal-burning emissions. It is suggested that industrial emissions should be controlled priority and clean energy should be promoted, which could control the heavy metal pollution of atmospheric deposition in the area.