材料期刊网

以徐州煤矿混推复垦区为研究对象，采用Tessier连续提取法，对该复垦区土壤Zn、Pb、Ni、Mn、Cu、Cr等6种重金属含量进行分析和风险评价．结果表明，除Cr外，复垦区土壤Zn、Pb、Ni、Mn和Cu的含量均大于当地土壤背景值，但均未超过国家土壤环境质量二级标准，不同复垦年限下土壤重金属含量差异较大，Zn、Mn总体上随复垦年限延长，积累越明显．形态分析表明，Pb和Mn以铁锰氧化物结合态为主；Zn、Ni、Cu和Cr以残渣态为主．徐州煤矿复垦区土壤重金属的生物可利用系数（ BF）的平均值大小为Mn＞Pb＞Cu＞Zn＞Cr＞Ni．各重金属的生态风险程度大小为Pb＞Cu＞Ni＞Mn＞Cr＞Zn．徐州煤矿复垦区土壤重金属的潜在生态风险指数范围是16．71—25．94，平均值为21．56，属于轻微生态危害．不同复垦年限下土壤重金属的综合潜在生态风险指数大小为1997年复垦＞2006年复垦＞1987年复垦＞2010年复垦＞塌陷未复垦＞未塌陷，各复垦年限下土壤重金属均属于轻微生态风险．

Soil samples were collected in a Xuzhou reclamation area of coal mine. Five step sequential extraction method was applied to investigate the speciation distribution characteristics of six heavy metals ( Zn, Pb, Ni, Mn, Cu, Cr) in the reclamation soils. Results showed that there was a rather large difference of the heavy metals accumulation under different reclamation years. The concentrations of five heavy metals ( Zn, Pb, Ni, Mn, Cu ) in the reclaimed soil exceeded background value of Jiangsu soil. But the concentrations of all 6 heavy metals in the reclaimed soil were all below the National Soil Environmental Quality Standard of GradeⅡ. Speciation analysis indicated that Pb, Mn were mainly in the Fe?Mn oxide form, while Zn, Ni, Cu, Cr were orimarily in the residual fraction. Bioavailability factor of the heavy metals ranked in the order of Mn > Pb >Cu > Zn > Cr >Ni. The heavy metal ecological risk was in the order of Pb >Cu >Ni >Mn >Cr >Zn. The potential ecological risk index of all heavy metals were between 16.71 and 25.94, the mean value was 21.56, indicating slight pollution. The ecological risk for different reclamation years was in the order of 1997 > 2006 > 1987 > 2010 > un?reclaimed > un?sunken, suggestiag slight pollution.