用同步辐射X荧光光谱分析了上海市郊区大气细颗粒和超细颗粒物(0.0287-2.40μm)中元素粒径分布、质量中值粒径、元素相关性和不同粒径颗粒物中的富集因子.Ca、Ti主要分布于粒径〉2μm的颗粒物中,它们之间的相关系数达0.933,富集因子在0.1-3.2之间,且与粒径无明显关联,主要来自土壤扬尘等自然来源.V、Cr、Mn、Ni、Zn、Cu、Pb、Cl、S等元素主要分布在0.1-1.0μm颗粒物中,质量中值粒径在0.56-0.94μm之间.V、Cr、Ni、Cu、Zn、Pb显著富集,且富集程度随粒径减小而增大.其中Pb在超细颗粒物(〈0.1μm)中的富集因子达2 023.7-2 244.2,远大于在细颗粒和PM2.5中的富集程度.这些元素主要来自燃油、燃煤、冶金和机动车尾气等人为污染.Fe在〉0.2μm颗粒物中分布较均匀,质量中值粒径1.3μm.除了局部污染源,远距离传输对该地区大气颗粒物污染有不可忽略的影响.
The elemental size distributions of airborne fine/ultrafine particulate matters in the suburb of Shanghai were studied using synchrotron X-ray fluorescence. Median mass aerodynamic diameter (MMAD), elemental correlation coefficient as well as enrichment factor (EF) of each size fraction were calculated to characterize the sources of elements in fine/ultrafine particulate matters. Ca and Ti distributed mainly in coarse particles ( 〉 2 μm) with size independent enrichment factors between 0.1 and 3.2, and the correlation coefficient between Ca and Ti was as high as 0.933, which implied strong contribution from nature sources, such as soil dusts and resuspended dusts. However, V, Cr, Mn, Ni, Zn, Cu, Pb, Cl, S mainly distributed in 0.1-1.0 μm particulate matters with MMAD between 0.56-0.94μm. The EF of V, Cr, Ni, Cu, Zn, Pb increased with decreasing particle size. The highest EF were found for Pb in nltrafine particulate matters ( 〈 0.1 μm) with EF of 2 023.7- 2 244.2. The evidences suggested that these elements were significantly influenced by anthropogenic sources and enriched in fine/ultrafine particles smaller than 1 μm. Fe distributed uniformly in the particles larger than 0.2μm with MMAD of 1.3 μm . The resnlts indicated nonnegligible influences of remote transmission of anthropogenic pollutions.