阿哈水库沉积物重金属形态分布及生态风险评价

On Speciation Distribution and Potential Ecological Risk Assessment of Heavy Metals in Sediments of Aha Reservoir

采用SWB-1型柱状采泥器采集阿哈水库沉积物柱状剖面样,利用BCR连续提取法研究沉积物样品中Cu,Zn,Cd,Pb的赋存形态分布特征,并采用基于重金属形态学研究的次生相与原生相比值法(RSP)对沉积物中4种重金属的潜在生态风险进行了初步评价.结果表明:Zn,Pb,Cu,Cd 4种元素的总量分别为:294.74,43.64,38.68,1.91mg/kg,其中Cu主要以残渣态存在;Zn,Cd主要以弱酸溶态、可还原态和残渣态存在;Pb主要以可还原态和残渣态存在.从RSP污染指数分析,阿哈水库沉积物中4种重金属的潜在生态风险从大到小依次为Cd,Zn,Pb,Cu.

By means of SWB-1 type columnar by the sediment columnar section,Aha Reservoir sediment samples have been collected.The speciation of heavy metals such as Cu,Zn,Cd and Pb in sediments has been studied by sequential extraction procedures,and the potential ecological risk of these heavy metals as-sessed on the basis of the rations secondary phase and primary phase （RSP）.The results show that the av-erage extracted contents of the four elements are found to be Zn：294.74 mg/kg,Pb：43.64 mg/kg,Cu：38.68 mg/kg,Cd：1.91mg/kg.Among which,Cu existed as residue lattice combining form;Zn and Cd existed as acid-soluble form,reducible form and residue lattice combining form;Pb existed as reducible form and residue lattice combining form.Base on the RSP,the potential ecological risk of heavy metals was in the descending order of Cd,Zn,Pb and Cu.