尾矿库尾砂及周边农田土壤重金属形态分布及其生物有效性

Speciation and Bioavailability of Heavy Metals in Tailings and Agricultural Soils

采用BCR(community bureau of reference)连续提取法对大宝山矿山槽对坑尾矿库尾砂和周边农田土壤重金属Cd、Pb、Cu和Zn的形态分布及其生物有效性进行了分析。结果表明,尾砂中Cd、Pb、Cu和Zn残渣态占绝对优势,占其总量的百分数均在85%以上。农田土壤中Cd、Cu和Zn都以残渣态为主,分别占其总量的60%、60%和90%以上,Pb以残渣态和可还原态为主,占其总量的93.44%。农田土壤重金属有效性较尾砂大,尾砂和农田土壤重金属生物有效性均以Pb为最高。

The three-step BCR （community bureau of reference ） sequential extraction procedure method was used to analyse the speciation and bioavailability of heavy metals （ Cd, Pb, Cu and Zn ） in tailings and agricultural soils around Caoduikeng mine tailing in Dabaoshan mountain area, Guangdong Province, China. Results showed that Cd, Pb, Cu and Zn were dominated by the residual fraction. The residual fraction of each metals accounted for more than 85% of the total content in mine tailing. And the Cd, Cu and Zn in agricultural soils were predominately located in residual fraction. The residual fractions of Cd, Cu and Zn accounted for more than 60%, 60% and 90% of their total contents, respectively. However, Pb was dominantly released in the reducible and residual fractions. The both fractions accounted for 93.44% of the total contents in agricultural soils. The bioavailabilities of heavy metals in agricultural soils were higher than those in mine tailings. And Pb had the highest bioavailability among these metals in the two both of tested samples.