Xu Zhen-Cheng, Yang Xiao-Yun, Wen Yong, Chen Gui-Hua, Fang Jian-De
South China Institute for Environmental Science, Ministry of Environmental Protection, Guangzhou 510655, China.
Huan Jing Ke Xue. 2009 Nov;30(11):3262-8.
In order to find out the heavy metals concentrations and their potential ecological risks of the sediments in Beijiang river's upper and middle reaches, 25 sediments specimens were sampled from both the trunk stream and tributaries for analyzing Cu, Pb, Zn, Cd, Ni, Cr, As and Hg. The Index of Geoaccumulation and the Potential Ecological Risk Index were then employed to evaluate the pollution degree of heavy metals in the sediments. The results indicate that the sediments in Beijiang River have been severely contaminated by many heavy metals. The descending order of pollution degree of various metals is: Cd >> Hg > Zn > As > Pb approximately to Cu > Ni > Cr; and similarly the potential ecological risk intensity caused by different metals is: Cd >> Hg > Pb approximately to As > Cu > Zn > Cr, and Cd is the predominant element among them. In general, because the trunk stream receives huge waste discharge, the pollution degree of heavy metals is stronger in the trunk stream than that in the tributaries due to long time accumulation. The Maba River is the worst polluted among the tributaries, and the Zhengshui River and Wongjiang River are next to it.
为了解北江中下游沉积物中重金属含量及其潜在生态风险，从干流和支流采集了25个沉积物样本，分析其中铜、铅、锌、镉、镍、铬、砷和汞的含量。随后采用地累积指数和潜在生态风险指数评估沉积物中重金属的污染程度。结果表明，北江沉积物已受到多种重金属的严重污染。各种金属污染程度由高到低依次为：镉>>汞>锌>砷>铅≈铜>镍>铬；不同金属引起的潜在生态风险强度依次为：镉>>汞>铅≈砷>铜>锌>铬，其中镉是主要元素。总体而言，由于干流接纳大量废弃物排放，长期积累导致干流重金属污染程度强于支流。支流中马坝河污染最严重，其次是浈水和翁江。
