The Yellow River, with its extremely high sediment loads, and the Yellow River Estuary (YRE) serve as a vital conduit for material exchange between land and marine environments, where sediment–phosphorus interactions profoundly influence nutrient cycling, ecological health and eutrophication potential. This paper reviews the distribution of phosphorus in overlying water and sediment, the characteristics of phosphorus migration and transformation across the sediment–water interface, and the effecting factors of phosphorus migrate, such as sediment properties and environmental factors in the YRE. Inorganic phosphorus was the dominant form in the overlying water and sediment. Suspended sediment acts as a dynamic reservoir for phosphorus transportation in the YRE. The dynamic estuarine environment promotes sediment deposition, which helps reduce phosphorus levels in the water. Upon entering the Bohai Sea, sediment is transformed into the source of phosphorus. The released phosphorus may increase the nutrient load in shallow Bohai Sea waters. Fine particles demonstrate strong adsorption capacity for reactive phosphorus, acting as the primary carriers for phosphorus migration at the sediment–water interface. The grain size of the suspended sediment in the Yellow River exhibited significant sorting characteristics with varying sediment content, consequently affecting the forms of phosphorus. Likewise, the influence of biogeochemical conditions on the transport and transformation of sediment and phosphorus was further analyzed and the partial least squares-path model of related variables on estuarine phosphorus is constructed to interpret the behavior of sediment and phosphorus in the YRE. Finally, the current situation and indeterminacy of water quality models in the estuary were appraised. The priority of analyzing and revealing the environmental behaviors of phosphorus in a sediment-laden river estuary in the future was further proposed against the present deficiencies. This review holds significant practical importance for enhancing the assessment of ecological environment quality and ecological restoration in the YRE.

Extreme rainfall events significantly affect groundwater systems by altering hydrogeological conditions and accelerating the migration of pollutants, exacerbating the ecological vulnerability of over-exploited areas. However, there is a lack of systematic research on the ecological response mechanisms of microbial communities under extreme rainfall. This study focuses on the over-exploited area in the western North China Plain. Based on 16S rRNA sequencing analysis of 49 groundwater samples collected from the typical alluvial–diluvial plain in the study area impacted by extreme precipitation induced by Typhoon Doksuri, we revealed the effects of rainfall on the taxonomic composition, assembly mechanisms, and environmental drivers of groundwater microbial communities. We found that extreme rainfall influenced the distribution of dominant genera in groundwater and enriched tolerant bacterial communities, further causing a decline in groundwater microbial diversity. Our study confirmed that abundant subcommunities displayed strong microbial collaborations, while rare subcommunities exhibited higher sensitivity and evolved toward opportunistic groups after extreme rainfall. Rainfall influenced the composition of rare taxa, while enhancing the influence of stochastic processes to the assembly of subcommunities. Functionally, confined water favored anaerobic carbon fixation, methanogenesis and dissimilatory sulfate reduction, whereas the Calvin–Benson–Bassham pathway, nitrification, and denitrification were enriched in phreatic water. Additionally, abundant taxa exhibited significantly responses to carbon nutrients in shallow groundwater, whereas rare taxa were governed by mineral ions in deep confined aquifers after rainfall. This study expanded our knowledge of the groundwater microbiome driven by extreme rainfall events and was of great significance to the assessment of ecological stability in the western North China Plain.

Mining can significantly affect the spatial distribution and temporal evolution of groundwater chemistry. From July to August 2024, the research team collected 26 surface water and groundwater samples in the Shengli Coal Mine area of the Mongolian Plateau, conducting comprehensive hydrogeochemical analyses on surface water flowing through the mining area, groundwater within the mining area, seepage water, and groundwater outside the mining area. The results indicate that groundwater in this region is notably affected by human activities such as mining operations. Specifically, in surface water flowing through the mining area, concentrations of total dissolved solids (TDS), sulfates, nitrates, and nickel showed significant increases. Compared to groundwater systems in other areas of the Mongolian Plateau, nickel levels in the mining area’s groundwater were significantly higher, while nitrate levels exhibited the opposite trend. A significant positive correlation was observed between metal element concentrations in surface water and groundwater. The study found that abnormal distributions of heavy metals such as beryllium (Be), thallium (Tl), and tin (Sn) may originate from point-source pollution caused by mining activities. Furthermore, concentrations of manganese (Mn), arsenic (As), and antimony (Sb) in the groundwater of this area exceeded relevant regulatory limits, with arsenic being particularly prominent. The levels of arsenic in both surface water and groundwater may pose carcinogenic risks to human health. This study shows that nearly half of the sampled water bodies in the area require purification treatment to meet drinking water standards, highlighting the urgent need for further attention to water quality safety issues. The conclusions derived from this research provide theoretical support for understanding the long-term evolutionary mechanisms of groundwater in mining areas, while also offering important insights for improving groundwater environmental management and ensuring water resource security in mining regions.