惠州仲恺高新技术开发区土壤重金属的污染及评价

Pollution and Assessment of Soil Heavy Metals in Zhongkai Hi-tech Development Zone of Huizhou

采集仲恺高新区土壤样品53个,测定了样品中铜(Cu)、砷(As)、镉(Cd)、铬(Cr)和铅(Pb)5种重金属的含量。参照国家土壤环境质量标准(GB15618-1995中的一、二级标准),采用单项污染指数法、综合污染指数法以及潜在生态危害法等方法对土壤重金属污染进行评价。结果发现,53个样品中,Cr的含量未有超标,共有3个样品的As和Cd含量超过二级标准,Pb和Cu的含量全部符合二级标准。单因子和综合污染指数表明,研究区域土壤没有受到5种重金属的污染,土壤处于尚清洁状态。重金属元素污染潜在生态危害系数和污染分级统计结果表明,5种重金属并不存在潜在生态危害,Cr的生态危害程度最低。潜在生态危害综合指数表明该区重金属污染潜在生态危害风险等级为轻微。这一研究对进一步明确该区土壤重金属背景值,为政府环境治理决策和其它类似区域的重金属污染研究提供了参考。

53 soil samples were collected from ZhongKai High-tech Development Zone of Huizhou and the content of 5 heavy metals involving copper(Cu),lead(Pb),cadmium(Cd),arsenic(As) and chromium(Cr) were studied. Their pollution status were evaluated according to class I and II of Soi1 Environmental Quality Standard(GB15618—1995),using the single pollution index,comprehensive pollution index and potential ecological harm coefficient methods. Results showed that among the 53 soil samples,no samples showed Cr content exceeding the class II threshold.Cu and Pb contents in all samples were under class II threshold except that in 3 samples As and Cr content exceeded class II threshold. Single pollution index and comprehensive pollution index indicated that the studied soil was not polluted by 5 heavy metals,it is still clean. Results of potential ecological harm coefficient and pollution classification statistics indicated,there was no potential ecological harm of 5 heavy metals for the studied soil. Cr had lowest potential ecological harm to soil among 5 heavy metals. Potential ecological harm complex coefficient indicated that risk level of heavy potential ecological harm in the studied area belong to slight class. This study would not only be helpful to confirm the background value of heavy metal in the studied soil,but also provide useful clue for the government's decision on environmental governance and other similar areas' study on heavy metal.Zhongkai High-tech Development Zonesoilheavy metalpollutionassessment