With the rapid development of economy and the concentrated populations, more and more pollutants entry into the water environment in coastal areas of the Yangtze River Estuary. Field investigations were conducted twice in this study to evaluate the characteristics of heavy metals in the coastal areas of the Yangtze River Estuary in January 2021. Eight sampling locations were selected as Liu Estuary (LHK), Shi Dong Kou (SDK), Wu Song Kou (WSK), Zhu Yuan (ZY), San Jia Gang (SJG), Chao Yang Nong Chang (CYNC), Da Zhi River (DZH), Nan Hui (NH). Eight sediment samples and eight water samples were collected, and the heavy metal distribution characteristics were analyzed. The results have shown that the concentrations of Cr, Cu, Zn, Cd, and Pb in the surface sediment sample were 51.96-97.25, 18.40-28.03, 46.47-94.45, 0.185-3.095, 11.28-32.08 mg/kg. The Sediment Quality Guideline was used to evaluate the biological effect of sediment. The results show that the most negative impact of heavy metals in these areas were Cr and Cu. They have acute or chronic toxicity to organisms in water, which will reduce the number of organisms.
In recent years, with the rapid development of economy, pollution from industrial and agricultural production enters the Yangtze River Delta and adjacent areas. Although the contaminant can be degraded through various chemistry and biological processes, there are still many contaminants such as heavy metals, which can be accumulated in the environment and harmful for the ecosystems. Heavy metal has become a serious environmental problem due to its toxicity, persistence and difficult degradation (Zhang et al., 2015; Yi et al., 2017; Dou et al., 2013). These heavy metals experience the physicochemical process such as adsorption, analysis, precipitating resuspension in the estuary area (Jian et al., 2003). It causes most heavy metals to transfer in the suspended sediment and is deposited in the bottom sediment. Under the complex hydrodynamic action of the Yangtze River, the high concentration of the heavy metal is easy to discharge, causing secondary pollution of the ecosystem of the Yangtze River (Oh,2009).
This paper investigates the distribution law of heavy metals in sediments in part of the sewage, port, landfill and river intersection, and evaluates heavy metals in the Yangtze River mouth Pollution by Sediment Quality Guideline.
