某废弃铅锌选矿厂场地土壤重金属污染健康风险评估及其来源解析

Health Risk Assessment and Source Analysis of Soil Heavy Metal Pollution in an Abandoned Lead and Zinc Concentrator

以西北某废弃铅锌选矿厂为研究对象,分析场地土壤中Cu、Zn、Ni、As、Hg、Pb和Cd的含量变化及空间分布特征,对场地土壤进行健康风险评估,并通过主成分和相关性分析探究其来源途径。结果表明:Pb、As、Cd、Zn和Hg在场地土壤中均有不同程度超标,最大超标倍数分别为14.75、7.6、3.71、9.16和1.11,污染较严重的区域主要分布在生产车间、产品沉淀池、原料堆放区和产品堆放区,随着土壤深度的增加,超标重金属的含量均呈下降趋势。Cu、Zn、Ni、As、Pb和Cd的来源途径相同,可能与铅精粉和锌精粉的生产有关;Hg与其他重金属的来源途径无明显相关关系,可能是外来土壤造成的污染。根据场地健康风险评估结果,As、Pb和Cd超过了人体可接受风险水平,需尽快采取有效的修复手段和管控措施。

Taking an abandoned lead-zinc concentrator in Northwest China as the research object,analysis of the content changes and spatial distribution characteristics of Cu,Zn,Ni,As,Hg,Pb and Cd in the soil of the site,conduct health risk assessment on site soil and explore its source through principal component and correlation analysis.The results showed that Pb,As,Cd,Zn and Hg all exceeded the standard in different degrees in the site soil,and the maximum exceedance multiples were 14.75,7.6,3.71,9.16 and 1.11,respectively.The areas with more serious pollution are mainly distributed in the production workshop,product sedimentation tank,raw material stacking area and product stacking area.With the increase of soil depth,the content of excessive heavy metals shows a downward trend.The sources of Cu,Zn,Ni,As,Pb and Cd are the same,which may be related to the production of lead concentrate and zinc concentrate;there is no obvious correlation between Hg and other sources of heavy metals,which may be the pollution caused by foreign soil.According to the results of site health risk assessment,As,Pb and Cd exceed the acceptable risk level for human body,and effective restoration methods and control measures should be taken as soon as possible.