海陵湾表层沉积物主要重金属污染特征及其来源解析

Pollution characteristics and sources analysis of main heavy metals in surface sediments from the Hailing bay

为了解海陵湾表层沉积物主要重金属的污染特征,本研究以2017年11月海陵湾的采样调查为基础,分析了表层沉积物中铜(Cu)、铅(Pb)、锌(Zn)、镉(Cd)、汞(Hg)、砷(As)和铬(Cr)7种重金属的含量和空间分布特征,利用单因子指数、地累积指数、潜在生态风险指数和一致性沉积物质量基准等指标定量评价了沉积物中重金属的污染特征,利用相关分析和主成分分析探讨了海陵湾表层沉积物中重金属的来源。研究结果显示,除As和Cr外,其余重金属在海陵湾表层沉积物中的含量整体处于较低水平;重金属整体属无污染和轻微生态风险状态,相对污染主要以As、Cr的贡献为主,且这两种重金属的含量在部分站位处于阈值效应含量和可能效应含量之间,有25%~75%的概率引发毒性,产生有害生物效应;Cu、Zn、Cd、Hg和As之间有一定的同源性,主要受地质背景和有机质降解的控制,Pb、Cr和As还分别受到船舶废气、工业废水废气和阳江港煤炭运输的影响。

In order to understand the pollution characteristics of major heavy metals in surface sediments of Hailing bay, based on the sampling survey of Hailing bay in November 2017, this study analyzed the content and spatial distributions of seven heavy metals, and evaluated the marine sediment pollution characteristics by using indicators such as single factor pollution index, geoaccumulation index, heavy metal potential ecological risk and consensus-based sediment quality guidelines. Moreover, the sources of heavy metals in the surface sediments of Hailing bay were analyzed by using correlation analysis and principal component analysis. The results indicated that, except As and Cr, the rest of the heavy metal content in the Hailing bay surface sediments was at a low level as a whole. The heavy metals as a whole are in a state of pollution-free and slightly ecological risk in Hailing bay, and the relative pollution was mainly based on contribution of the contribution of As and Cr. The content of these two heavy metals is between TEC and PEC, with 25% ~ 75% probability of causing toxicity and harmful biological effects. There was a certain homology among the heavy metals in sediments, such as Cu, Zn, Cd, Hg and As, which were mainly controlled by geological background and degradation of organic matter. Pb, Cr and As were also affected by ship exhaust gas, industrial waste gas and coal transportation in Yangjiang port.