江西某铅锌矿区土壤重金属形态分析及风险评价

Speciation Analysis and Risk Assessment of Heavy Metals in the Soil of a Lead-Zinc Mining Area

这是一篇矿山环境工程领域的论文。土壤重金属污染影响时间长,具有较高的生物毒性,严重威胁人类健康。为了研究铅锌矿区土壤重金属污染现状和评估重金属污染风险,以江西某铅锌矿区为研究对象,采用改进BCR连续提取法分析了某铅锌矿区土壤样品重金属元素(Cu、Pb、Zn、Cd)形态,并对重金属元素相关性进行了研究,利用风险评价编码法和次生相与原生相分布比值法评价了重金属元素的环境风险。结果表明:铅锌矿区土壤中Cu、Zn、Cd、Pb元素全量超标,Cu、Zn、Pb元素以残渣态为主,相较于Cu、Zn、Pb元素,土壤样品中Cd元素酸可提取态含量高,生物有效性强,Cd元素污染严重。矿区土壤样品中Cu、Zn、Pb元素残渣态含量均与全量呈极显著正相关,Cd元素残渣态与全量相关性不显著;酸可提取态中Cu、Zn、Cd、Pb元素含量呈极显著正相关,酸可提取态与pH值呈负相关。风险评价编码法和次生相与原生相分布比值法分析的结论较为一致,均为Cd元素污染严重,环境风险高,Cu、Pb、Zn元素污染较轻,环境风险低。本文可为铅锌矿区土壤重金属污染防治提供参考。

This is a paper in the field of mining environmental engineering.Heavy metal pollution in soil has a long-time impact,with high biological toxicity and serious threat on human health.In order to study the present situation of soil heavy metal pollution in a lead-zinc mining area and assess its risk,a lead-zinc mining area was taken in Jiangxi as the study object,and the speciation contents of heavy metal elements(Cu,Pb,Zn,Cd)in the soil samples of a lead-zinc mining area were analyzed by themodified BCR successive extraction,and the correlation of heavy metal elements was studied.The environmental risk of heavy metal elements was evaluated by the method of risk assessment coding(RAC)and ratio of secondary phase and primary phase(RSP).The results showed that:The Cu,Zn,Cd and Pb elements in the soil of the lead-zinc mining area exceeded the standard,and the Cu,Zn and Pb elements were mainly in residual state.Compared with Cu,Zn and Pb,Cd element had a higher content of acid extractable state,and its bioavailability was strong,so the pollution of Cd element was serious.The residual-state contents of Cu,Zn and Pb in the soil samples of the mining area were significantly positively correlated with the total contents,while the residual-state contents of Cd were not significantly correlated with the total contents.The contents of Cu,Zn,Cd and Pb in the acid extractable state were significantly positively correlated,but the contents of acid extractable state was negatively correlated with pH value.The conclusion of risk assessment coding method and ratio method of secondary phase and primary phase was relatively consistent,which showed that the pollution of Cd element was serious with a high environmental risk,while that of Cu,Pb,Zn elements was relatively light with a low environmental risk.This paper is expected to provide reference for the prevention and control of soil heavy metal pollution in the lead-zinc mining area.