广西企沙半岛近岸表层海水重金属分布、来源及生态风险评价

为研究企沙半岛近岸表层海水重金属的含量分布特征及质量现状，笔者于2020年11月在企沙半岛近岸海域采集表层海水样品67份，分析海水的理化性质和6种重金属含量。结果显示，As、Cd、Cr、Cu、Pb、Zn的含量分别为（2.06±0.89）μg/L、（0.08±0.06）μg/L、（2.13±0.76）μg/L、（1.91±0.74）μg/L、（0.22±0.19）μg/L、（16.17±12.89）μg/L。与研究区近10年的数据相比，Cr与As有所增加，其他元素的含量大致持平或略有下降。重金属的分布范围不具有明显的规律性，推断可能有不同的来源。研究区大部分海水符合《海水水质标准》（GB 3097-1997）一类水质标准，少数符合二类、三类水质标准。影响水质的元素主要为Cu和Zn，水质综合指数结果表明，海水为清洁级。利用风险熵对海洋生物的重金属生态风险进行评价，结果表明，Cu、Zn、As存在生态风险。相关性分析和聚类分析显示，重金属含量与总磷、盐度有一定的关系。利用PCA-MLR模型对重金属的来源进行解析，得出船体涂料及废水、自然背景岩石风化、工业及养殖废水3种来源贡献率分别为41%、4...

Distribution,source analysis and ecological risk assessment of heavy metals in surface seawater near Qisha peninsula,Guangxi

In order to study the distribution characteristics and quality status of heavy metals (HMs) in the surface seawater near Qisha peninsula, 67 surface seawater samples were collected in the coastal waters of Qisha peninsula in November 2020 to analyze the physical and chemical properties and HMs content in seawater. The results showed that the contents of As, Cd, Cr, Cu, Pb and Zn were (2.06 ± 0.89) μg/L, (0.08±0.06) μg/L,(2.13±0.76) μg/L, (1.91±0.74) μg/L, (0.22±0.19) μg/L and (16.17±12.89) μg/L respectively. Compared with the data in the past 10 years, the concentration of Cr and As was increased, and other elements were roughly the same as or slightly decreased. The distribution range of HMs has no obvious similarity, indicating that they may have different sources. Most of the seawater meets the seawater quality class I, and a few sites are in class II and class III. The elements affected the water quality were mainly Cu and Zn. The comprehensive water quality index (WQI) showed that the surface seawater was at clean level. Using risk quotient (RQ) to evaluate the ecological risk of HMs to marine organisms, it was considered that the main risk elements were Cu, Zn and As. With the correlation analysis and cluster analysis, it was considered that the content of HMs had a certain relationship with total phosphorus and salinity. PCA-MLR model was used to analyze the sources of HMS. Three sources such as hull coating and wastewater, natural background rock weathering and industrial and aquaculture wastewater were get, and the contribution rates were 41%, 48% and 11% respectively.