巢湖北岸烔炀河流域池塘沉积物中重金属污染特征

Characteristics of Heavy Metal Pollution in Pond Sediments of the Tongyang River Basin on the North Bank of Chaohu Lake

在巢湖北岸烔炀河流域,选择不同利用类型的池塘钻取了沉积物柱状样,分析了沉积物重金属元素浓度,并剖析了重金属在水平、垂向上的分布特征和污染程度。结果表明,池塘表层沉积物中Cr、As、Hg、Cd、Cu、Pb、Ni、Zn浓度分别为56.5~91.0、6.4~10.1、0.06~0.11、0.10~0.25、18.07~28.77、11.58~17.60、15.94~19.0、42.26~68.07 mg/kg;垂向上随着沉积物深度增加,重金属浓度总体呈下降趋势。烔炀镇老镇区池塘(S1)表层沉积物中重金属浓度高于其他池塘。烔炀河流域池塘沉积物中重金属Cr、Hg、Cu、Zn、As等5种重金属元素具有同源性,受成土母质影响,而Ni、Pb、Cd 3种重金属受人类活动影响;池塘表层沉积物重金属综合潜在生态风险指数处于轻微生态风险。

Columnar sediment samples were collected from ponds of different usage types in the Tongyang River basin on the north bank of Chaohu Lake.The concentrations of heavy metal elements in these samples were examined,and the horizontal and vertical characteristics as well as pollution levels were analyzed.Results reveal that the concentrations of Cr,As,Hg,Cd,Cu,Pb,Ni and Zn in the surface sediments of the ponds ranged 56.5-91.0 mg/kg,6.4-10.1 mg/kg,0.06-0.11 mg/kg,0.10-0.25 mg/kg,18.07-28.77 mg/kg,11.58-17.60 mg/kg,15.94-19.0 mg/kg,and 42.26-68.07 mg/kg,respectively.In vertical direction,the concentrations of heavy metals decreased with sediment depth.The Old Township Pond(S1)suffered from higher levels of heavy metal contamination in surface sediments than other ponds.Five heavy metal elements,namely Cr,Hg,Cu,Zn and As,exhibit homogeneity and are influenced by the soil-forming parent material,while Ni,Pb and Cd are affected by human activities.The comprehensive potential ecological risk index of heavy metals in the surface sediments of ponds in the Tongyang River basin is classified as a slight ecological hazard.