东莞市PM_1中重金属元素的污染特征及来源解析

Pollutioncharacteristics and source apportionment of heavy metals in PM_1 at Dongguan,China

采集了2011年8月—2012年7月间东莞市不同区域两点(A:生活区;B:工业区)的PM2.5～10、PM1～2.5和PM1样品,并用ICP-MS分析了颗粒物上Pb、Cu、Zn、As、Cd、V、Mn、Cr、Hg和Al等10种元素,重点研究了PM1中除Al外其它9种重金属元素的污染特征.分析结果显示,工业区B点PM1中的重金属污染明显较生活区A点严重,9种重金属元素在B点PM1中的浓度是A点的2.3～4.4倍.Zn和Pb是A、B两点PM1中主要的重金属元素,同时各重金属元素质量占PM1质量百分比范围为0.0008%～0.3530%.粒径分布、富集因子分析的结果显示,大部分重金属元素主要富集在PM1中,且主要受人为源的影响.因子分析源解析结果表明,A、B两点PM1主要来源于4类污染源:燃煤源、机动车/工厂燃油源、冶金化工源、土壤尘.污染源特征分析表明,偏北风时东莞地区PM1受局地源远距离输送影响更严重,偏南风时受本地污染源影响更严重.

PM2.5-10, PM1- 2.5 and PMl were sampled from August 2011 to July 2012 at different sites of A and B （A： living area; B： industrial area） in Dongguan, China. In addition, elemental compositions （Pb, Cu, Zn, As, Cd, V, Mn, Cr, Hg and A1） of ambient particles were determined using ICP-MS and characterization of heavy metals in PMl was performed. Our results showed that the concentrations of these heavy metals in PM1 at B site were about 2.3 -4.4 times those at A site, indicating that the heavy metal pollution in PM1 at the industrial site was more serious than that at the living site. Among these nine heavy metals, Zn and Pb were the primary elements in PM1. Heavy metals accounted for 0. 0008% - 0. 3530% of PM1 mass. Size distribution and enrichment factor analysis suggested that most of the nine heavy metals were mainly enriched in PMl and were primarily emitted by anthropogenic sources. Source apportionment analysis further revealed that PM1 at both sites primarily originated from coal combustion, vehicle/industrial oil burning, metallurgic emission and soil dust. Moreover, PM1 in Dongguan was mainly affected by non-local source with north wind and by the local sources with south wind.