摘要
以大兴安岭中南段农牧交错带一废弃铅锌矿为例,采集不同深度土壤样品,综合运用多种统计方法,结合典型剖面深浅层土壤重金属含量对比分析阐述了矿区重金属的空间分布特征,运用地累积指数法和生态风险评价法评价了矿区重金属累积程度和潜在生态风险,并对重金属来源和迁移转化驱动因子进行了剖析。结果表明,研究区表层土壤特征累积污染元素为Cd、Zn、Pb和As,超农用地土壤污染风险筛选值比例分别为53.62%、46.38%、44.93%和37.68%。重金属地累积程度由强至弱依次为:Cd>Zn>Pb>As>Cu>Cr>Ni>Hg,地累积程度达中等—强累积以上水平Cd、Zn、Pb和As样品占比分别为44.93%、39.13%、20.09%和14.96%,Cu、Cr、Ni和Hg元素累积程度较低。土壤重金属综合潜在生态风险总体属中度水平,7.25%土壤样品点达高风险水平。矿区重金属高值区主要位于矿山构筑物周边和尾矿库下风向,重金属垂向迁移深度有限,空间迁移分布主要受风力作用驱动,土壤Cd、Zn、Pb、As和Cu元素来源于成土母岩风化和人为活动共同作用,其它元素受人为活动影响相对较小。研究表明,矿区土壤重金属来源及迁移主要为原生地质环境影响,还与人类采选矿活动密切相关。
The spatial distribution and ecological risk assessment of soil heavy metals are of great significance to the environmental protection and restoration of the mining area.Soil samples of different depths were collected in an abandoned lead-zinc mine in the farming pastoral ecotone of the central and southern Greater Xing’an Mountains.The spatial distribution characteristics of the heavy metals were assessed by multivariate statistical methods and comparative analyzing of heavy metal contents in typical soil profiles.The results indicated that Cd、Zn、Pb and As were the characteristic cumulative pollutants in the topsoil,and the proportion of Cd、Zn、Pb and As content in soil exceeding the standard of risk screening value of soil pollution in farmland was 53.62%,46.38%,44.93%and 37.68%respectively,The average accumulation index of topsoil followed an order of Cd>Zn>Pb>As>Cu>Cr>Ni>Hg.The Index of geo-accumulation that classified as the moderate to strong level of soil Cd、Zn、Pb and As content accounted for 44.93%、39.13%、20.09%and 14.96%respectively.The accumulation of Cu,Cr,Ni and Hg was relatively lower in soil.The potential ecological risk of heavy metals belongs to the moderate level in the mass,while 7.25%of the soil sample categorized as the high-risk level.The concentration area of heavy metals in the mining area was mainly located around the mine structures and downwind of the tailings pond.The vertical migration depth of heavy metals was limited,and the spatial migration distribution is mainly driven by the action of wind.The Cd,Zn,Pb,As and Cu in the soil were derived associated with the combination of parent material and anthropogenic contributions.Cr,Ni and Hg were less affected by human activities and were at relatively low pollution level.
作者
李多杰
孙厚云
卫晓锋
黄行凯
陈自然
李健
郭颖超
LI Duojie;SUN Houyun;WEI Xiaofeng;HUANG Xingkai;CHEN Ziran;LI Jian;GUO Yingchao(Beijing Institute of Geology for Mineral Resources Co.,Ltd.,Beijing 100012;School of Water Resources and Environment,China University of Geosciences,Beijing 100083;Chengde huakan 514 geological and mineral testing research Co.,Ltd.,Chengde 067000)
出处
《矿产勘查》
2021年第4期1030-1039,共10页
Mineral Exploration
基金
中国地质调查局项目大兴安岭中南段有色金属基地综合地质调查(编号:DD20190815)资助。
