Size distribution of chemical elements and their source apportionment in ambient coarse, fine, and ultrafine particles in Shanghai urban summer atmosphere
Size distribution of chemical elements and their source apportionment in ambient coarse, fine, and ultrafine particles in Shanghai urban summer atmosphere
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上海城市夏季大气粗、细、超细颗粒物化学元素粒径分布及其来源解析
DOI：
10.1016/s1001-0742(11)60870-x
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发表时间：
2012-01-01
影响因子：
6.9
通讯作者：
Wang, Qingyue
中科院分区：
文献类型：
--
作者：
Lu, Senlin;Zhang, Rui;Wang, Qingyue
于2008年夏季（8月27日至9月8日）对上海市大气中的粗颗粒物（直径1.8-10 μ m）、细颗粒物（直径0.1-1.8 μ m）和超细颗粒物（直径< 0.1 μ m）进行了采样。通过扫描电子显微镜结合能量色散X射线光谱（SEM/EDX）研究了颗粒的微观表征。通过使用同步辐射X射线荧光（SRXRF）来定量尺寸分辨颗粒中Si、P、S、Cl、K、Ca、Ti、V、Cr、Mn、Fe、Ni、Cu、Zn、As、Se、Br、Rb、Sr和Pb的质量浓度。采用富集因子法对化学元素进行了源解析。我们的结果表明，夏季空气中粗颗粒物、细颗粒物和超细颗粒物的平均质量浓度分别为9.38 +/- 2.18、8.82 +/- 3.52和2.02 +/- 0.41 μ g/m3。细颗粒物占PM10总质量的51.47%，表明细颗粒物是上海市大气颗粒物的主要成分。SEM/EDX结果表明，粗颗粒以矿物质为主，细颗粒以烟灰聚集体和飞灰为主，超细颗粒以烟灰颗粒和不明颗粒为主。SRXRF结果表明，地壳元素主要分布在粗颗粒中，而重金属在细颗粒中所占比例较高。源解析结果表明，Si、K、Ca、Fe、Mn、Rb、Sr等元素主要来源于地壳源，S、Cl、Cu、Zn、As、Se、Br、Pb等元素主要来源于人为源。颗粒物中P、V、Cr和Ni的含量可能是多源的，需要进一步研究。
Ambient coarse particles (diameter 1.8-10 mu m), fine particles (diameter 0.1-1.8 mu m), and ultrafine particles (diameter < 0.1 mu m) in the atmosphere of the city of Shanghai were sampled during the summer of 2008 (from Aug 27 to Sep 08). Microscopic characterization of the particles was investigated by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDX). Mass concentrations of Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr, and Pb in the size-resolved particles were quantified by using synchrotron radiation X-ray fluorescence (SRXRF). Source apportionment of the chemical elements was analyzed by means of an enrichment factor method. Our results showed that the average mass concentrations of coarse particles, fine particles and ultrafine particles in the summer air were 9.38 +/- 2.18, 8.82 +/- 3.52, and 2.02 +/- 0.41 mu g/m(3), respectively. The mass percentage of the fine particles accounted for 51.47% in the total mass of PM10, indicating that fine particles are the major component in the Shanghai ambient particles. SEM/EDX results showed that the coarse particles were dominated by minerals, fine particles by soot aggregates and fly ashes, and ultrafine particles by soot particles and unidentified particles. SRXRF results demonstrated that crustal elements were mainly distributed in the coarse particles, while heavy metals were in higher proportions in the fine particles. Source apportionment revealed that Si, K, Ca, Fe, Mn, Rb, and Sr were from crustal sources, and S, Cl, Cu, Zn, As, Se, Br, and Pb from anthropogenic sources. Levels of P, V, Cr, and Ni in particles might be contributed from multi-sources, and need further investigation.