Present study investigated heavy metal pollution in the continuous upper river−estuary−sea systems of the Yellow River Delta (YRD). Significant seasonal differences (p < 0.05) for the heavy metal overall profile were observed, although there were no significant spatial variations among the different water bodies. Positive matrix factorization indicated that heavy metals primarily originated from anthropogenic activities (e.g., oil field development, mining, and agricultural activities). Chemical oxygen demand, water temperature, electrical conductivity, dissolved oxygen, pH, and salinity influenced the distribution of heavy metals in water. The NO3− and total phosphorus concentrations were the main influencing factors in sediment, with both showing positive correlations with all heavy metals. Furthermore, low ecological risks were observed for sediment based on the values of the ecological risk and potential ecological risk indexes in the YRD. This study will assist with the effective control and management of heavy metal pollution in a continuous river−estuary−sea system.

中文翻译：

---

黄河三角洲连续河-河口-海洋系统重金属研究：空间格局、潜在来源及影响因素


本研究调查了黄河三角洲 （YRD） 连续上游河流-河口-海洋系统中的重金属污染。观察到重金属总体剖面的显著季节性差异 （p < 0.05），尽管不同水体之间没有显着的空间变化。正矩阵分解表明，重金属主要来源于人为活动（例如，油田开发、采矿和农业活动）。化学需氧量、水温、电导率、溶解氧、pH 值和盐度影响水中重金属的分布。NO3− 和总磷浓度是沉积物中的主要影响因素，均与所有重金属呈正相关。此外，根据长三角地区生态风险和潜在生态风险指数的值，观察到沉积物的生态风险较低。这项研究将有助于有效控制和管理连续河流-河口-海洋系统中的重金属污染。