盐城北部潮间带表层沉积物重金属分布特征及污染评价

对采自盐城北部潮间带的241个表层沉积物样进行测试分析,探讨了沉积物中重金属(Cu、Pb、Zn、Cr、Cd、As、Hg)空间分布特征及各元素相关关系,并采用Hakanson潜在生态风险指数法进行了污染评估。结果表明:1)研究区重金属Zn、Pb、Hg含量均符合国家规定的一类沉积物标准,Cr、Cd、Cu、As含量在大部分站位也都低于一类沉积物标准,其中Cr仅在个别站位处达到二类沉积物标准,Cd、Cu、As在少数站位达到二类沉积物标准。2)研究区Cu、Pb、Zn、As四种元素在物源或迁移累积特征上具有相似性,Cd元素不受元素粒度控制律控制。3)研究区重金属总体污染和潜在生态危害处于低风险级别,重金属潜在生态危害系数由大到小依次为:CdAsCuPbCrZnHg。

Distribution and pollution assessment of heavy metals in surface sediments of the intertidal zone in the North Yancheng

The heavy metals(Hg, As, Cu, Pb, Zn, Cd, Cr) were analyzed for 241 surface sediment samples collected over intertidal mud flat of Northern Yancheng. Then we studied their spatial distribution patterns, and correlations among heavy metal concentrations. The ecological risk regarding heavy metals was assessed by using Hakanson Potential Ecological Risk Assessment Mothed.(1) The concentrations of Zn, Pb and Hg reached National First-class Sediment Standard. However, only most samples of Cr, Cd, Cu concentrations reached National First-class Sediment Standard, others meeting National Second-class Sediment Standard.(2) The source and accumulation of Cu, Pb, Zn and As were similar. The Cd concentration was not grain-size dependent.(3) We concluded that the potential ecological risk was low in the study area. The potential ecological risk was Cd Hg As Cu Pb Cr Zn.