人为活动对城市湖泊沉积物重金属污染的影响——以武汉墨水湖为例

人类活动使得大量的重金属向水环境中排放,导致了城市湖泊严重的重金属污染.为了研究中国的工业化、城市化发展对城市水体重金属污染的影响,以武汉墨水湖为例,测定了沉积物中几种常见痕量重金属Zn、Pb、Ni、Cu、Cr的含量和富集系数,并运用主成分分析对重金属的污染来源进行了初步探讨.结果表明,墨水湖表层沉积物重金属污染程度较重,主要受人为输入的影响;5种重金属在全湖区域上具有比较高的富集系数,尤以排污口为甚,排污口是重金属富集的主要区域.主成分分析表明,Pb可能主要来自于暴雨径流面源,而Cr可能主要来自于工矿企业的点源排放,其他3种金属则有着大小相当的点、面源输入贡献。以上结果表明,城市化和工业化进程已经给城市湖泊带来了很高的重金属污染负荷.

Metals in Sediments of an Urban Lake in China as Archives of Anthropogenic Activities-A Case Study of Moshui Lake in Wuhan

The pollution status of heavy metal in an urban lake—Moshui Lake in Wuhan city, China was studied by determining contents and enrichment factors of 5 trace heavy metals—Zn, Pb, Ni, Cu and Cr, which were inputted into lake by anthropogenic activities and were preserved in lake sediments. The input sources of these metals were also explored by Principal Component Analysis(PCA). High heavy metal pollution extent was found in the whole urban lake due to anthropogenic activities. The highest enrichment factors were found in the waste water input estuary. PCA analysis of acid extractable heavy metal contents showed that Pb might mainly come from non-point sources, while Cr might mainly come from point sources(industrial and mining enterprises). The data showed that urbanization and industrialization process had caused high loads of heavy metals to the urban lakes.