河流底泥重金属污染及潜在生态风险评价——以湘江株洲段为例

Pollution and Potential Ecological Risk Assessment of Heavy Metals in River Sediments——Case Study on the Zhuzhou Section of Xiang River

通过对湘江株洲段6个监测断面左右两岸共32个底泥样品重金属Pb,Zn,Cd,As,Hg和Cr质量比进行分析研究,并进行潜在生态风险评价。结果表明:霞湾断面是重金属富集最严重的断面;Cd,Hg和As的含量均超过GB15618-1995三级标准和长沙-湘潭-株洲3市土壤背景值;重金属含量大部分分布特征为右岸高于左岸;从重金属污染的潜在生态风险看,湘江株洲段各监测断面潜在生态风险都很高;各重金属元素对生态风险影响程度从大到小的顺序为:Hg>Cd>As>Pb>Zn>Cr。

The contents of heavy metals including Pb, Zn, Cd, As, Hg and Cr in 32 sediment samples collected from the both banks of Zhuzhou section of Xiang River were analyzed, and the potential ecological risk was evaluated. It is concluded that Xiawan section concentrates the heavy metal most, where the contents of Cd, Hg and As exceeded the three standard GB15618-1995 and the background level of soils in the cities of Changsha, Xiangtan and Zhuzhou. The heavy metals distributes as the right bank higher than the left bank. The potential ecological risk of heavy metals are very high at all the monitoring spots in Zhuzhou Section of Xiang River. The influence degrees of potential ecological risk of heavy metals rank as Hg 〉 Cd 〉 As 〉 Pb 〉 Zn 〉 Cr.