干旱区煤矿重金属污染生态风险综合评价——以准东红沙泉煤矿为例

Comprehensive Evaluation of Ecological Risk of Heavy Metal Pollution in Coal Mines in Arid Areas—Taking Zhundong Hongshaquan Coal Mine as an Example

针对干旱脆弱生态区的煤炭资源开采土壤重金属污染问题,以准东红沙泉露天煤矿及其周边地区为研究对象,测定其50个样点的Cr、Cu、Zn、Hg的含量,运用地质累积指数法、潜在生态危害指数法、富集指数及转移系数法,对采样点土壤重金属污染状况进行了综合评价。结果显示:研究区土壤中的Cr、Zn、Hg含量均超过准东地区的背景值,Cr、Cu、Zn之间存在一定相关性,土壤重金属的蓄积与矿区生产活动有关;矿区以及芨芨湖地区地质累积指数分别达到4.81,3.38,表现出中度污染,潜在生态危害指数强度上表现为:矿区>芨芨湖>雀仁乡>将军庙;矿区内琵琶柴对Cu的富集指数达到了1.07,芨芨湖地区琵琶柴对Hg的富集指数达到了4.4,说明琵琶柴对土壤重金属有富集转运作用;土壤重金属含量分布沿道路走向,与煤矿的开发及运输有关,4种重金属含量在非主要运输道路的将军庙路段均低于车流量集中的芨芨湖与矿区中心位置。

Aiming at the problem of heavy metal pollution in soil of coal mining in arid and fragile ecological areas,taking Zhundong open-pit coal mine and its surrounding areas as the research object,the contents of Cr,Cu,Zn and Hg in 50 sampling points were determined.The pollution status of heavy metals in soil was comprehensively evaluated by using geological accumulation index method,potential ecological hazard index method,enrichment index and transfer coefficient method.The results are concluded as follows.Firstly,the contents of Cr,Zn and Hg in the soil of the area exceed the background values of Zhundong area,and there is a certain correlation among contents of Cr,Cu and Zn,and the accumulation of heavy metals in the soil is related to the production activities in the mining area.Secondly,the geological accumulation index of the mining area and Jiji lake area reaches 4.81 and 3.38 respectively,showing moderate pollution.The potential ecological hazard index intensity is as follows:mining area>Jiji lake>Queren town>Jiangjunmiao.Thirdly,the enrichment index of Reaumuria Linn to Cu in the mining area is 1.07,and the enrichment index of Reaumuria Linn to Hg in Jiji lake area is 4.4,which indicates that Reaumuria Linn has an enrichment and transport effect on heavy metals in soil.At last,the distribution of heavy metal content in soil is along the road trend,which is related to the development and transportation of coal mine.The content of four heavy metals in the section of Jiangjunmiao road,which is not the main transportation road,is lower than that in the center of Jiji lake and the mining area where traffic flow is concentrated.