| 工矿型绿洲城郊排污渠沉积物重金属的形态分布规律及风险评价 |
| 摘要点击 3093 全文点击 1380 投稿时间：2014-06-25 修订日期：2014-09-04 |
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| 中文关键词 工矿型绿洲 沉积物 重金属 形态 风险评价 |
| 英文关键词 industrial oasis sediment heavy metals speciation risk assessment |
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| 中文摘要 |
| 采用 Tessier连续提取法、相关分析、富集因子法 (EF)和风险评价编码法 (RAC),研究了干旱区工矿型绿洲(以白银为例)城郊排污渠沉积物重金属 Cu、Zn、Cd、Pb、Ni、Cr的形态分布规律及潜在环境风险. 结果表明, 东、西大沟沉积物中各重金属元素平均含量除 Cr外, 均明显高于甘肃省土壤背景值. 富集因子法评价表明, 东、西大沟沉积物中 Cd富集较为严重, 达极强污染水平. 形态分析表明, 东大沟沉积物中 Zn、Ni、Cr以残渣态为主, Cu、Cd以有机结合态为主, Pb以铁锰氧化物结合态为主; 西大沟沉积物中 Pb以铁锰氧化物结合态为主, 其余元素均以残渣态为主. 风险评价编码法 (RAC)结果显示, 东大沟沉积物各重金属的风险等级为:Ni>Cd>Pb>Cu>Zn>Cr,其中 Ni的风险等级最高, 处于高风险水平; 西大沟沉积物各重金属的风险等级为:Pb>Cd>Ni>Cu>Zn>Cr. 其中 Cd、Pb、Ni风险等级最高, 处于高风险水平. |
| 英文摘要 |
| The speciation distribution and potential environmental risk of Cu, Zn, Cd, Pb, Ni, Cr in sediments in suburban outfall of industrial oasis region, Baiyin City were studied by Tessier sequential extraction method, correlation analysis, enrichment factor (EF) and risk assessment code (RAC). The results indicated that, the average concentration of heavy metals in sediments samples of Dongdagou and Xidagou streams exceeded the background levels in Gansu Province, with Cr, as an exception. The enrichment factor suggested that the enrichment of Cd in sediments of Dongdagou and Xidagou streams were very serious, which posed a strong pollution level. Furthermore, the analysis of chemical speciation indicated that Zn, Ni, and Cr in sediments of Dongdagou stream were mainly dominated by the fraction of residual, the existence of Cu and Cd was mainly in organic forms, while Pb was composed mostly by its Fe-Mn oxides fraction; Pb in sediments of Xidagou stream existed by Fe-Mn oxides fraction, other metals mainly appeared with the residual fraction. The risk assessment code (RAC) showed that the risk level of heavy metals in sediments of Dongdagou stream descended in the order: Ni>Cd>Pb>Cu>Zn>Cr, Ni posed a highest risk level. The risk level of heavy metals in sediments of Xidagou stream decreased in the order: Pb>Cd>Ni>Cu>Zn>Cr, Cd, Pb and Ni posed a highest risk level. |
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