秦岭柞水县下梁镇金属矿区土壤重金属富集污染研究

A Study on Heavy Metal Accumulation and Pollution in Soils of Xialiangzhen Metal Mining Area

为了探明矿产资源开发对环境中土壤重金属富集的影响,以地处秦岭的柞水县下梁镇大西沟铁矿矿区及其周围环境土壤为研究对象,采用Cr、Ni、Cu、Zn、Pb、As、Hg和Cd测试分析的国家相关标准及方法,对该矿区及周围环境中的重金属含量进行测试分析,并采用单因子指数法和内梅罗(Nemerow)综合污染指数法对核心区、缓冲区、过渡区和对照区土壤环境质量和污染状况进行评价。结果表明,矿区核心区土壤污染指数除Cr、Cu、As超标外,其余重金属均未超过标准值,其单因子污染指数排序为P_(Cu)>P_(As)>P_(Cr)>P_(Cd)>P_(Zn)>P_(Pb)>P_(Hg);缓冲区土壤污染指数除As、Cu超过标准外,其余重金属均未超过标准,单因子污染指数排序为P_(Cu)>P_(As)>P_(Cr)>P_(Cd)>P_(Zn)>P_(Hg)>P_(Pb);过渡区土壤污染指数除Cu超标外,其余重金属均未超过标准,单因子污染指数排序为P_(Cu)>P_(As)>P_(Cr)>P_(Cd)>P_(Hg)>P_(Zn)>P_(Pb);对照区土壤污染指数均未超标,单因素污染指数排序为P_(Cr)>P_(Cu)>P_(As)>P_(Pb)>P_(Zn)>P_(Cd)>P_(Hg)。潜在生态风险评价分析表明,柞水矿区土壤重金属污染的潜在生态风险是轻微的,今后应加强监测防范土壤的进一步污染而造成中度以上级别的潜在生态风险。

In order to explore the impact of mineral resources development on the accumulation of heavy metals in soils,the Daxigou iron mine area and surrounding areas in Zhashui County were taken as the research objects.The contents of heavy metals,including Cr,Ni,Cu,Zn,Pb,As,Hg and Cd in the soils of the study areas were measured by using the relevant national standards and methods.The environmental quality of the soils and pollution status in core area,buffer area,transition area and control area were evaluated by single factor index method and Nemerow comprehensive pollution index method.The results showed that in the core area,except for Cr,Cu and As,the other heavy metals did not exceed the standard values.The order of single factor pollution index was P_(Cu)>P_(As)>P_(Cr)>P_(Cd)>P_(Zn)>P_(Pb)>P_(Hg).In buffer area,except for As and Cu that exceeded relative standard,the other heavy metals did not exceed the standard,and the order of single factor pollution index was P_(Cu)>P_(As)>P_(Cr)>P_(Cd)>P_(Zn)>P_(Hg)>P_(Pb).In the transition area,except for Cu,the other heavy metals did not exceed the standard values,the order of single factor pollution index was P_(Cu)>P_(As)>P_(Cr)>P_(Cd)>P_(Hg)>P_(Zn)>P_(Pb).In the control area,all the heavy metals did not exceed the standard,the order of single factor pollution index was P_(Cr)>P_(Cu)>P_(As)>P_(Pb)>P_(Zn)>P_(Cd)>P_(Hg).The potential ecological risk assessment showed that the potential ecological risk of heavy metal pollution in the soils of Zhashui mining area was slight,monitoring should be strengthened in the future to guard against further soil contamination resulting in potential ecological risks of medium to high levels.