邯郸市PM_(2.5)化学组成特征及来源解析

Chemical Compositions and Source Apportionment of PM_(2.5) in Handan City, Hebei Province

该研究通过对邯郸市环境空气中PM_(2.5)样本进行采集和成分检测,分析了该地区PM_(2.5)的浓度及化学组成特征,利用相关性分析法和富集因子法定性判断了PM_(2.5)的主要来源,利用PCA模型定量计算了各类污染源的贡献率,最后将解析结果与已有的PMF模型结果进行了对比分析。结果表明,邯郸市PM_(2.5)日均浓度(2012年10月13日-2013年1月)为146.9 g/m3,是我国环境空气质量标准(Ⅱ级)的2倍。二次水溶性离子、OC、EC是邯郸市PM_(2.5)的主要成分,约占PM_(2.5)总质量浓度的71.5%,其中,OC是PM_(2.5)中含量最丰富的单个组分,大气有机污染特征明显。PCA模型源解析结果为:工业和燃煤33.3%,二次气溶胶和生物质燃烧21.7%,机动车为12.8%,道路扬尘9.1%。将PCA、PMF模型解析结果对比后发现2种模型对PM_(2.5)的来源有较为一致的判定,工业源和燃煤源是该地区PM_(2.5)的主要来源,两者的总贡献率分别为42.1%(PMF)和33.3%(PCA)。除此之外,PMF单独解析出了Ba、Mn、Zn源,K、As、V源和重油燃烧源,PCA单独解析出了生物质燃烧源,不同的解析结果一方面与模型本身有关,另一方面与模型选择的化学成分有关。

To investigate the chemical compositions and major sources of PM_（2.5）in Handan City, Hebei Province, PM_（2.5）samples are collected on an urban site. Mass concentrations and chemical components of PM_（2.5）are analyzed by enrichment factors and correlation analysis to study the dominant sources of PM_（2.5）. The contributions of each source are calculated by PCA, and then the results from PCA and PMF are compared. The results show that the daily mean concentration of PM_（2.5）during the study period is 146.9 g/m3, which is nearly two times of the allowed limit of Grade Ⅱ 75 g/m3 in National Air Quality Standard. Secondary water soluble ions, OC, EC are the major components of PM_（2.5）, accounting for approximately71.5% of the total concentration of PM_（2.5）. OC is the most abundant component of PM_（2.5）, indicating the obvious characteristics of organic aerosol pollution. In PCA, 33.3% of the PM_（2.5）mass can be attributed to the mixture of coal combustion and industry, 21.7% to the mixture of secondary origin aerosol and biomass burning, 12.8% to the vehicle emissions, 9.1% to the road dust. The results obtained from PCA and PMF are comparable, in which coal combustion and motor vehicle are the major sources of PM_（2.5）, the corresponding contributions of these two sources are 42.1% and 33.3% by PMF and PCA,respectively. In addition, three additional sources including Ba, Mn, Zn, and K, As, V, and oil combustion are segregated by PMF, while biomass burning is segregated by PCA. The discrepancies of the results from the two models may come from the model itself as well as the chemical components selected in each model.