滏阳河河系表层沉积物重金属污染特征及其风险评价

采集滏阳河表层沉积物,分析了6种重金属的污染特征,并采用富集系数法和Hankanson潜在生态危害指数法分析了重金属的来源,进而评价其环境风险.结果表明,沉积物中重金属Cr、Cu、Cd、Pb、Zn、Ni的平均含量分别为340.09、90.28、1.28、65.87、760.71、48.62 mg·kg-1,均在一定程度上超过了河北省土壤元素背景值.重金属富集系数分析结果显示,元素Cd、Zn在整个流域尺度内主要源于人为输入,Cr在邵村排干河段及Cu、Pb、Ni在汪洋沟上游河段受人为排放源影响较大,主要是由于河流沿线城市生产和生活污水的排放造成.单一金属的潜在生态危害指数评价结果显示,沉积物中Cd污染达到极强生态危害,其次为Cu、Pb和Zn,而重金属综合生态危害指数(RI)评价表明,滏阳河沉积物重金属总体处于强生态风险,其中,汶河河段达到很强生态风险.

Characteristics and ecological risk assessment of heavy metal pollution in surface sediments of Fuyang River

In order to study the characteristics of sediment heavy metals pollution in Fuyang River and its tributaries, surface sediment samples were collected, enrichment factors were calculated to trace sources, and the environment risks were assessed using Hankanson potential ecological risk index. The results showed that the average concentrations of Cr, Cu, Cd, Pb, Zn and Ni were 340.09, 90.28, 1.28, 65.87, 760.71 and 48.62 mg·kg^-1, respectively, all of which were higher than soil background values in Hebei Province. Enrichment factor values of those metals revealed that both Cd and Zn were effluent from anthropogenic activities at the whole basin. Anthropogenic activities also contributed significantly to Cr in Shaocunpaigan ditch and Cu, Pb, Ni in the upstream of Wangyanggou ditch, due much to the industrial and domestic wastewater. Potential ecological risk assessment suggested that Cd pollution posed a very high ecological risk in the study area, whereas Ni had a low potential ecological risk. The integrated metal pollution assessment revealed a considerable ecological risk in riverine sediment of Fuyang River system, in particular the Xiao River.