滏阳河表层沉积物重金属的赋存形态研究

Heavy metal speciation in the surface sediments of Fuyang River

利用BCR三步提取法测定滏阳河表层沉积物中重金属Cu、Cr、Cd、Pb、Zn、Ni的赋存形态,分析环境因子与其赋存形态的关系,并采用污染评估指数法(RAC)评价沉积物中重金属的生态风险程度.结果表明,不同重金属元素赋存形态存在较大差异,Cu、Cr主要以有机物及硫化物结合态存在;Cd、Zn主要以酸可提取态存在;Pb、Ni的主要赋存形态为残渣态.相关性分析显示,有机质及含硫量均与可氧化态相关性显著.评价结果显示6种元素中,Cd、Zn存在的生态风险最大,均属于高风险程度,Ni处于中度风险程度,Cu、Pb存在低风险,Cr基本处于无风险范围.

The Community Bureau of Reference （BCR） extraction technique was applied to examine the speciation of six heavy metals （ Cu, Cr, Cd, Pb, Zn and Ni） in the surface sediment of Fuyang River, China. The relationship between environmental factors and heavy metal speciation were analyzed. And the environmental risk was assessed using the Risk Assessment Code （RAC）. The results showed that there was a prominent difference among the chemical speciation of six heavy metals. Cu and Cr existed mainly in organic and sulfide bound-state; Cd and Zn in acid-soluble fraction. And Pb and Ni exsited mainly in residual fraction. The correlation analysis indicated that both of the organic matter and sulfur content were positively correlated with the oxidizable fraction of the six heavy metals. The results of RAC implied that Cd and Zn were high risk elements, Ni was medium risk, Cu and Pb posed low risk, while Cr posed no risk.