Abstract
Heavy metals present a significant risk to the safety of water environments and aquatic ecosystems due to their resistance to degradation and high levels of toxicity. Field investigations were conducted in this study in Yangtze River Estuary in July, 2021 and February, 2022. Seven sampling locations were selected at Liu He Kou (LHK), Shi Dong Kou (SDK), Wu Song Kou (WSK), Zhu Yuan (ZY), San Jia Gang (SJG), Chao Yang Nong Chang (CYNC), Da Zhi He (DZH). Fourteen sediment samples and fourteen water samples were collected. The heavy metal concentrations (Cr, Ni, Cu, Pb, Zn, Cd) and physicochemical parameters of water quality including Temperature (Temp), pH, Oxygen redox potential (ORP), Dissolved oxygen (DO), Electrical conductivity (EC), Electrical resistivity (RES), Total dissolved solids (TDS), Salinity (SAL) and turbidity (NTU) were investigated. The concentrations of most heavy metals were higher in July compared to February, and exhibited spatial heterogeneity. Principal component analysis (PCA) was used to determine the sources of heavy metals. Steel industry wastewater, domestic and industrial sewage, shipping and vessel emissions were the main sources of heavy metals. Spearman correlation analysis identified Temp, pH, and DO as the key physicochemical parameters of water quality, exhibiting the strongest correlation with heavy metal concentrations in sediment and water samples. These results can provide scientific basis and guidance for the water environmental management of the Yangtze River estuary, making a significant contribution to the protection of water quality and health in this region.
