Effect of leaching on the heavy metal forms in polluted soil around the mining area
In this paper,the heavy metal polluted soil around the Dabaoshan mining area in Shaoguan City,Guang-dong Province was taken as the research object,and the EDTA,citric acid,and oxalic acid was used as leaching agents to remove the Pb,Zn,Cu,and Cr in the soil.In addition,the changes of heavy metals forms in the soil before and after leaching were studied to analyze the influence of the existing forms of heavy metals on the leaching effect and the effect of the leach-ing on the heavy metals forms.The results showed that the overall removal effects of the three leaching agents on Pb,Zn,Cu and Cr were in order of oxalic acid>EDTA>citric acid,Cu>Cr>Zn>Pb.Using the Tessier five-step extraction method to an-alyze the heavy metals forms of the soil before and after oxalic acid leaching,it was found that the leaching effect has a cer-tain relationship with the existence of heavy metals,and leaching can effectively remove heavy metal ions in the form of ex-changeable and carbonate-bound states.Compared with the heavy metal forms in the soil before leaching,the proportions of the exchangeable state and carbonate-bound state after leaching decreased,the proportions of the iron-manganese ox-ide-bound state and organic-bound state increased overall,and the proportions of the residue state increased obviously,it can effectively reduce the environmental risk of heavy metals in the soil.
Mining areaSoilLeachingHeavy metal formOxalic acids
万方数据
维普
