电子废弃物拆解旧场地土壤重金属污染特征及生态风险评价初探

目的]探讨历史污染与潜在生态风险之间的相关性。方法]采用野外采样和实验室分析相结合的方法,以某电子废弃物拆解旧场地表层土壤为研究对象,分析了土壤中重金属Cd、Ni、Cr、Cu、Pb、As和Hg的含量及污染特征,并在此基础上采用地累积指数法和潜在生态危害指数法对土壤重金属污染进行了生态风险评价。结果]研究区仍受到一定程度的重金属污染,土壤中各元素的含量均高于背景值,其富集程度依次为Cd>Hg>Cu>Cr>Pb>Ni>As;研究区土壤的潜在生态风险级别为D级,生态危害程度为很强,7种重金属中元素Cd的风险指数最高。结论]因历史污染源造成的生态风险存在。

Typical Characteristics of Soil Heavy Metal Pollution of a Land Where Deserted Electronic Equipment was Taken Apart and Assessment of Its Ecological Risk

Objective] The study aims to discuss the correlation between historical pollution and potential ecological risk.Method] Through field sampling and laboratory analysis,the content of heavy metals(Cd,Ni,Cr,Cu,Pb,As and Hg) in the surface soil of an old electronic waste land and their pollution characteristics were analyzed,and then its ecological risk was assessed by using geo-accumulation index and potential ecological harm index.Result] The study farmland was polluted by heavy metals to some extent,and the contents of various heavy metals were above the background values,and they were arranged in order of content as follows: Cd>Hg>Cu>Cr>Pb>Ni>As.The potential ecological risk of the soil ranked Class D,and its ecological harm was very high.Among the seven heavy metals,the ecological risk index of Cd reached the top.Conclusion] There existed potential ecological risk caused by historical pollutants in the study farmland.