都柳江沉积物重金属污染特征及生态风险

Pollution Characteristic and Ecological Risk Evaluation of Heavy Metals in Duliu River

水体重金属污染源广泛,重金属危害严重,持续时间久,很容易通过食物链对人体造成伤害。对都柳江沉积物重金属污染特征以及潜在生态危害调查分析显示,从上游到下游,都柳江干流沉积物重金属铜、镍、铅、钴、锌含量呈升高趋势,砷、铊含量则呈降低趋势;Hakanson潜在生态危害指数(RI)显示干流RI平均值为6 063,支流的RI平均值为2 328。都柳江干、支流锑的高生态危害对其高生态风险贡献值最大。分析表明,都柳江流域水体污染特征与上游多砷、汞、锑等矿床分布特征相吻合,上游的半坡锑矿、维寨锑矿及中游的兴华锑矿的废污水排放是造成都柳江潜在生态危害高风险的主要原因。

Heavy metal pollution source in river did wide and serious harm, and will cause damage to human being via food chain. The heavy metal pollution also existed in sediments, and led to a potential ecological risk. An thorough investigation for Duliu River shown an increase of Ni, Pb, Zn content and a reduce of As and Tl content. The results also showed that the average RI( the potential ecological risk index) in mainstream is 6 063, but the average RI in brunch is 2 328. The higher RI of Sb contributed most of RI in Duliu river. The study indicated that the pollution character is same with the nonferrous metal mine distribution. Mine waste water from Banpo antimony mine,Weizhai antimony mine and Xinghua antimony mine is the main reason for the high risk of potential ecological hazard in Duliu River.