铜陵某富硫尾矿库周边土壤重金属污染特征及风险评价  

Heavy metal pollution characteristics and risk assessment of soil around a sulfur-rich tailings pond in Tongling

作　　者：夏毅民 郑刘根[1] 邱征 汪雲龙 李杨[1] XIA Yimin;ZHENG Liugen;QIU Zheng;WANG Yunlong;LI Yang(Anhui Province Engineering Laboratory for Mine Ecological Remediation,School of Resources and Environmental Engineering,Anhui University,Hefei Anhui 230601)

机构地区：[1]安徽大学资源与环境工程学院,安徽省矿山生态修复工程实验室,安徽合肥230601

出　　处：《环境污染与防治》2020年第4期493-499,共7页Environmental Pollution & Control

基　　金：国家自然科学基金资助项目(No.41373108、No.41702176);安徽省重点研究与开发计划项目(No.201904a07020027)。

摘　　要：铜陵某尾矿库堆积大量富硫尾矿,为研究其氧化状况及对周边土壤的污染情况,在尾矿库和周边采集尾矿及土壤样品,测试分析尾矿及土壤样品典型重金属(Hg、As、Cr、Cd、Pb、Zn)含量和赋存形态,并基于单因子污染指数法和内梅罗综合污染指数法对土壤污染状况进行了评价。结果表明:(1)尾矿中Fe2O3平均占比达到38.08%(质量分数,下同),S平均占比达到5.34%;(2)尾矿库周边土壤中Cd、As、Zn、Hg严重超标,分别为《土壤环境质量农用地土壤污染风险管控标准(试行)》(GB 15618—2018)风险筛选值的6.3、3.7、1.8、1.5倍;(3)土壤中重金属主要以残渣态形式存在,但Cd、Hg、Zn的非残渣态平均占比均达到25%以上,生物有效性较高,对周边环境存在潜在危害;(4)两种污染指数法评价结果表明,尾矿库周边土壤以Cd、As、Zn污染为主,该富硫尾矿库已对周边环境造成重度污染。A large amount of sulfide-rich tailings were accumulated in a tailings pond in Tongling.In order to study the oxidation status of the tailings and the tailings’pollution to the surrounding soil,tailings and soil samples were collected in the tailings pond and surrounding areas.The concentration and occurrence of typical heavy metals(Hg,As,Cr,Cd,Pb,Zn)in tailings and soil samples were determined.By adopting both the single factor index method and the Nemerow muti-factor index method,the pollution indices were calculated to assess soil pollution extent.The results showed that:(1)the average proportion of Fe2O3 in tailings was 38.08%(mass fraction,the same below)and the average proportion of S was 5.34%.(2)The concentrations of Cd,As,Zn and Hg in the soil samples around the tailings pond were seriously out of standard,which were 6.3,3.7,1.8 and 1.5 times of the risk screening values of“Soil environmental quality-risk control standard for soil contamination of agricultural land”(GB 15618-2018),respectively.(3)The heavy metals in soils mainly existed in the form of residue.The proportion of non-residual state of Cd,Hg and Zn was more than 25%of total concentrations,which indicated that the bioavailability of heavy metals was high.This had caused great potential harm to the surrounding environment.(4)The calculated pollution indices showed that the soils around the tailings pond was dominated by Cd,As and Zn pollution.The sulfide-rich tailings pond in the studying area had caused serious pollution to the surrounding environment.

关 键 词：尾矿库 土壤 重金属 赋存特征 污染评价 

分 类 号：X53[环境科学与工程—环境工程]