石家庄市大气PM1、PM2.5和PM10中重金属元素分布特征及来源的对比研究

Comparative study on the distribution characteristics and sources of heavy metal elements in PM1,PM2.5 and PM10 in Shijiazhuang City

为了解元素(尤其是重金属元素)在不同粒径大气颗粒物中的分布规律、污染特征及来源,于2016年在石家庄市采集PM1、PM2.5和PM10样品。利用等离子体质谱仪(ICP-MS)测定了Al、Ti、V、Cr、Mn、Fe、Cu、Zn、As、Sb、Hg、Pb和Cd共13种元素的质量浓度,采用富集因子(EF)法分析各种元素在PM1、PM2.5和PM10中的分布特征,并通过主成分分析法讨论了这些元素的主要来源。富集因子分析显示出Al、Fe、Ti、Mn受人为因素影响较少(EF<10),其他元素则出现显著至极强的人为影响,尤其是Cd元素(EF>103),并发现颗粒物粒径较小时,富集因子较大,即人为因素影响更重。主成分分析表明:PM1中元素有工业冶炼及燃煤活动、机动车燃油排放、生活燃煤3个来源,PM2.5中元素有地壳源、电厂及居民生活燃煤、金属冶炼等工业活动、机动车尾气4个来源,PM10中元素有化石燃料燃烧和地壳源、与机动车相关的道路扬尘及工业尘、垃圾焚烧及机动车排放与磨损、燃煤活动4个来源。

In order to investigate the pollution characteristics and sources of chemicals(especially heavy metals)in atmospheric particles of different sizes,we collected PM1,PM2.5 and PM10 samples from Shijiazhuang City in 2016.We determined the mass concentrations of 13 elements including Al,Ti,V,Cr,Mn,Fe,Cu,Zn,As,Sb,Hg,Pb and Cd by ICP-MS.We analyzed the distribution characteristics of these elements in PM1,PM2.5 and PM10 by the enrichment factor(EF)method,and discussed the main sources of these elements based on principal component analysis(PCA).The enrichment factor analysis showed that Al,Fe,Ti,and Mn were less influenced by human factors(EF<10),while other elements had significant to extremely strong human influences,especially Cd(EF>103).In addition,smaller particle size correlates with larger enrichment factor,indicating greater influence of human factors in small particles.Principal component analysis showed that there are three sources for the elements in PM1 and four for PM2.5 or PM10.The sources are mainly related to industrial activities,fossil fuel combustion,motor vehicle exhaust and wear,and garbage burning.