【摘要】 为评估不同粒径降尘重金属形态与有机物含量的相关性,测定山西运城市3种不同粒段降尘颗粒中不同形态As、Pb、Cd、Cr、总有机碳(TOC)及水溶性有机碳(WSOC)含量,并对重金属富集因子、生物有效性以及重金属赋存形态与有机碳含量之间的关联性进行了分析.结果表明:降尘中金属总含量呈现As>Cr>Pb>Cd,随粒径增大,富集重金属总量升高,不同粒段重金属形态区别不明显;随着粒径的减少,降尘中WSOC和TOC明显降低;降尘TOC和WSOC含量与某些形态的Pb、Cd、Cr之间具有较好的相关性,与As相关性较差;富集因子(EF)呈现Cd>As>Pb>Cr,其中Pb和Cd具有潜在的健康风险,Cr、As属于较稳定的元素.降尘颗粒来源不同,赋存有机物和重金属行为差异明显,不同粒段降尘颗粒环境风险不同.更多还原

【Abstract】 In order to evaluate the correlations between concentrations of heavy metal species and organic carbon in dustfall, dust samples were collected in Yuncheng city, Shanxi province, and then they were separated into three particle sizes. In this study, the chemical species of As, Pb, Cd, Cr, total organic carbon(TOC) and water-soluble organic carbon(WSOC) were measured, and their correlations were analyzed. In addition, enrichment factors of heavy metals and their bioavailability were determined. Results showed that the total metal concentrations decreased in the following order: As > Cr > Pb > Cd, and the accumulation of all heavy metals increased with increasing particle size, while little difference was found in the chemical species of heavy metals among different particle sizes. The concentrations of WSOC and TOC in dust decreased with the decreases of particle size. The concentrations of TOC and WSOC in dust showed good correlations with some chemical species of Pb, Cd and Cr but a poor correlation with As. The enrichment factor(EF) of heavy metals decreased as follows: Cd > As > Pb > Cr, where Cr and As were relatively stable with little ecological risk, while Pb and Cd exhibited potential health risks. There were significant differences in the behavior of organic compounds and heavy metals, as well as the environmental risks of dust particles in different particle sizes from diverse sources.更多还原