| Mining industry is the pillar industry and basic industry for the development of the national economy,and the treatment of heavy metal pollution in the soil around the mining area is one of the important aspects of environmental protection.This study takes Zaozigou gold mine as the research object.In order to understand the pollution in the mining area,select suitable remediation materials,and formulate effective protection measures.The concentration of heavy metals in the soil,plants,and sediments around the mining area and the physical and chemical properties of the soil are measured.,Calculate the geological accumulation index,risk index,plant enrichment and transportation coefficient and other methods to analyze the pollution degree,source,risk of heavy metals in the soil and the enrichment of heavy metals by native plants.The main conclusions are as follows:（1）The accumulation of heavy metals in the soil of the study area is higher than the background value,and the concentration of As is the highest,which may come from drainage from the mining area.The average values of As,Cd,Zn,Pb,Cr and Hg in the soil in the study area were 292.35,0.37,89.80,30.06,70.42,and 0.083 mg·kg-1,which were all higher than the local natural background value,and the As concentration was the highest.The average PLI of As is 15.30,indicating that the soil is extremely polluted by As.The average concentration of As in the river water is greater than the allowable value of 50μg·L-1,which is 753.52μg·L-1,and the average concentration in the downstream sediments of the river is higher than the severely affected level of 33 mg·kg-1,which is 594.91 and 92.06 mg·kg-1,respectively,which indicates that the increase in As may be related to mine drainage of gold mines.（2）The soil in the study area generally has a very high potential ecological risk and health risk.The PERI of heavy metal contaminated soil is 602.34,which is very high risk.The results of the health risk assessment showed that the HI of As for adults and children were 1.66 and 10.25,respectively.There is a non-carcinogenic health risk and the risk for children is higher.At the same time,the TCR of As in adults and children was 1.1×10-4 and 1.7×10-4,respectively,which exceeded the acceptable range of 1×10-6 to 1×10-4,thus indicating that As has a carcinogenic risk in the study area.（3）Studies on the enrichment of heavy metals in native plants show that Geranium pylzowianum Maxim.,Potentilla fruticosa L.and Artemisia frigida Willd.have the highest BCF-S and TF values for As,and can be used as potential enrichment plants for As restoration.The BCF-S and TF values of Potentilla saundersiana Royle,Swertia tetraptera Maxim.,Carpesium lipskyi Winkl.,Ligularia sagitta（Maxim.）Mattf.,Artemisia frigida Willd.,and Taraxacum mongolicum Hand.-Mazz.are higher for Cd,and can be used as potential enrichment plants for Cd restoration.Potentilla saundersiana Royle,Artemisia frigida Willd.,Potentilla fruticosa L.and Taraxacum mongolicum Hand.-Mazz.have higher BCF and TF values for Pb,which can be used as potential enrichment plants for Pb restoration.Taraxacum mongolicum Hand.-Mazz.and Artemisia frigida Willd.have higher BCF and TF values for Zn,and can be used as potential enrichment plants for Zn repair.The research results can provide references for soil environmental protection in this area. |
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