我国东南某海湾底泥重金属污染评价及分析

Assessment and Analysis of Heavy Metal Pollution in Sediment of a Bay in Southeast China

摘要:

对我国东南沿海某封闭海湾底泥中7种重金属（Cd、Pb、Cr、Cu、Zn、As、Hg）污染现状进行评价：表层底泥Cd、Pb、Cr、Cu、Zn、As单一污染物潜在生态风险系数（Eri）评价均为低生态风险，Hg单一污染物潜在生态风险系数（Eri）评价为低至重生态风险；多种重金属污染物潜在生态风险系数（RI）评价结果均为低至中等生态风险。同时，研究发现，重金属垂向浓度分布随着采样深度的增加逐渐降低。经分析，底泥重金属污染主要为沿岸入湾河流污染和雨季排口溢流污染。最终，根据重金属污染特征和评价结果，对该封闭海湾底泥分区分质疏浚以及疏浚后底泥就地消纳等资源化利用的可行性路径进行了探讨。该研究为封闭海湾重金属污染表征、底泥疏浚和疏浚后底泥资源化利用提供了技术支撑。

Abstract:

The pollution status of seven heavy metals (Cd, Pb, Cr, Cu, Zn, As and Hg) in the sediment of a closed bay in the southeast coast of China is assessed. The potential ecological risk coefficient (Eir) of the single pollutants Cd, Pb, Cr, Cu, Zn and As in the surface sediment is evaluated as low ecological risk. The potential ecological risk coefficient (Eir) of a single pollutant in Hg is evaluated as low to severe ecological risk. The potential ecological risk coefficient (RI) evaluation results of multiple heavy metal pollutants are all low to moderate ecological risks. Meanwhile, the research shows that the vertical concentration distribution of heavy metals gradually decreases with the increase of sampling depth. After analysis, the main sources of heavy metal pollution in the sediment are the pollution from the rivers flowing into the bay along the coast and the overflow pollution from the discharge outlets during the rainy season. Finally, based on the characteristics and evaluation results of heavy metal pollution, the feasible paths for resource utilization of the sediment in the closed bay are discussed, including zoning and quality dredging, and on-site consumption of dredged sediment. The study provides the technical support for the characterization of heavy metal pollution in closed bays, the sediment dredging, and the resource utilization of dredged sediment.