海州湾表层沉积物重金属的来源特征及风险评价

根据2009年12月海州湾海域17个站位的环境调查资料,通过地统计学方法分析表层沉积物中6种重金属(Cd、As、Cu、Pb、Cr、Zn)的来源特征,采用潜在生态风险指数法进行重金属风险评价.结果表明,重金属分布格局整体呈西南高东北低、随离岸距离增大而减小的趋势;陆源污染输入是海州湾海域重金属的重要污染来源;有机碳含量、底质粒径和硫化物是影响重金属含量及其分布的重要因素;风险评价显示海州湾沉积物重金属总体处于中等生态风险状况,风险相对较高主要分布在龙王河口到临洪河口的近岸海域,潜在生态风险指数Cd>As>Cu>Pb>Cr>Zn,Cd是主要的生态风险贡献因子.

Source Characteristics and Contamination Evaluation of Heavy Metals in the Surface Sediments of Haizhou Bay

Based on the investigation data from 17 sampling stations in the sea area of Haizhou Bay in 2009, the geo-statistics analysis was used to estimate the source characteristics of heavy metals in surface sediments, and the potential ecological risk index was applied to evaluate the status of the ecological risk. The contents of heavy metals showed a landward as well as northeastward increasing trend.The spatial distribution characteristics reflected that land-based inputs of pollution were the main sources of heavy metals. According to the analysis of Pearson correlation coefficients, the contents of organic carbon, sulfide and grain-size of sediments were important factors for the content and distribution of heavy metals. The results of potential ecological risk evaluation indicated that the Haizhou bay as a whole can be ranked as "moderate potential ecological risk". The high risk zone was in the coastal waters between Longwang estuary and Linhong estuary. The sequence of the potential ecological risk posed by the metals was Cd>As>Cu>Pb>Cr>Zn. Cd was the major pollutant among the metals in consideration, while the pollution related to others was less significant.