【摘要】 以湖南省郴州市某河道堆存尾砂为研究对象,分析了尾砂中Cu、Pb、Zn、Mn和As等重金属的形态特征分布,并采用潜在生态危害指数法对河道尾砂重金属潜在生态风险进行了评价。结果显示,Pb、Zn、Cu、Mn和As生物可交换态含量分别为18.66%、6.77%、5.12%、5.00%和0.10%,说明Pb对生物的可利用性较高,给环境造成的潜在风险较大,其他4种元素对生物的可利用性较低,潜在风险较小。5种重金属潜在生态危害系数由高到低排列为:As>Pb>Cu>Mn>Zn,As元素为极强危害等级,Pb元素为很强危害等级,Cu元素为中等危害等级,Mn和Zn元素为轻微危害等级。从生态危害指数来看,As对生态危害指数的贡献最突出,其次是Pb,该河道具有很强的生态风险。更多还原

【Abstract】 With sand tailings heaps in some riverway in Chenzhou city of Hunan province as an example, the morphological distribution of heavy metals,including Cu,Pb,Zn,Mn and As,were analyzed,and potential ecological risk index method was used to assess the potential pollution of heavy metals to the ecology.Results show biological exchangeable states of five heavy metals of Pb,Zn,Cu,Mn and As are 18.66%,6.77%,5.12%,5.00% and 0.10%,respectively,indicating Pb could bring a greater potential risk on the environment due to its higher bioavailabilities,but a lesser potential risk for other four heavy metals.According to their potential ecological risk factors,those five heavy metals are ranked in the following descending order: As>Pb>Cu>Mn>Zn,indicating that As is of the highest hazardous grade,and high grade for Pb,medium grade for Cu,lower grade for Mn and Zn.In terms of ecological risk index,As makes the prominent contribution,followed by Pb,resulting in a higher ecological risk for this riverway.更多还原