兴化湾海域水体和表层沉积物中重金属分布及其源解析

Heavy Metal Distribution and Its Source Analysis in Seawater and Sediments of Xinghua Bay

根据2015年春季兴化湾海域的环境调查资料,对海水和沉积物中的重金属分布及其来源进行了探讨。采用单因子污染指数法和地质累积指数法对海水和沉积物污染程度进行评价,并利用主成分分析法对其重金属的潜在来源进行解析。结果显示:表层海水中重金属Cd,As和Cr质量浓度符合海水水质一类标准,重金属Cu,Pb,Zn,Hg质量浓度均符合海水水质二类标准;表层沉积物中重金属Cu,Pb,Zn,Hg,As,Cd,Cr含量均符合海洋沉积物质量一类标准。地质累积指数评价结果显示,沉积物中重金属Cd总体为污染,其余6种重金属为清洁水平。表层沉积物中重金属间相关性分析表明,Hg与Cu,Zn之间具有相似的来源特征。研究区重金属潜在来源主要为江阴港周边入港船舶排放、生活污水和工农业生产的输入、周边河流输入和大气沉降等。

Based on the field survey data of seawater and surface sediments obtained from Xinghua Bay in the spring of 2015, this study analyzed and discussed the spatial distribution and sources of heavy metals were. By using methods of single factor contaminant and the geoaccumulation indices, this study evaluated the contamination level of the seawater and the surface sediments. The results showed that, in the surface seawater, the contents of Cd, As and Cr met the first class standard of seawater quality, and those of Cu, Pb, Zn and Hg were in line with the second class standard. In the surface sediments, the contents of Cu, Pb, Zn, Hg, As, Cd and Cr were in accordance with the first class of marine sediment quality standards. The evaluation results based on the method of geoaccumulation indices showed that Cd in the sediment was generally polluted and the remaining six elements were in clean level. The correlation analysis for heavy metals in surface sediments showed that Hg, Cu and Zn have similar source characteristics. Finally, we suggested that the potential sources of the heavy metals are mainly the marine traffic pollution, harbor dredging, terrestrial pollution via rivers and atmospheric deposition.