金沙江上游底泥重金属污染及潜在生态风险评价

对金沙江上游河段4个监测断面底泥中Cr、Pb、Zn、As、Hg、Cu和Cd 7种重金属含量进行分析研究,并进行潜在生态风险评价。结果表明,除Cd和As外,其他重金属的含量均符合GB15618-1995一级标准。Cd的富集程度最高,各采样点底泥中Cd含量均超过三级标准。臧曲河和相古底泥中的As含量高于三级标准。各监测断面的潜在生态风险都很高,Cd的潜在危害指数远大于其他金属,Cd是导致金沙江上游底泥中重金属潜在生态风险增加的主要原因。不同底泥的潜在生态风险依次为:臧曲河>相古>奔子栏>河坡。

Assessment of Heavy Metal PoUution in Sediment and Potential Ecological Risk in Upper Reach of Jinsha River

The heavy metal contents of Cr, Pb , Zn, As, Hg, Cu and Cd at the four monitoring points of the up- per Jinsha River are analyzed, and the potential ecological risk is evaluated. It shows that the contents of all of these metals are in compliance with the first grade of GB15618 - 1995, except for Cd and As. Cd has the highest concentration in the sediments, and it exceeds Grade Ⅲ of the standards in all sampled sediments. The content of As in Zangqu River and Xianggu sediments also exceeds Grade Ⅲ of the standards. The potential ecological risk of all the monitoring points is high. The potential hazards index of Cd is much greater than the other metals, and it in- tensifies the potential ecological risks in the sediments of the upper Jinsha River. The potential ecological risk in different sediments is ranked as Zangqu River 〉 Xianggu 〉 Benzilan 〉 Hepo.