Recent advances on iron bound phosphorus in wetland sediments: characteristics, influencing factors, interactions with organic matter and emerging contaminants

Phosphorus (P), as a key limiting element in wetland ecosystems, its occurrence forms, migration and transformation directly affect biological productivity and environmental safety. Among them, iron-bound phosphorus (Fe-P), as the most abundant reactive P form in sediments, dominates the bioavailability of P through the redox-driven dissolution-precipitation process. This work summarizes the data on P components in multiple wetlands around the world to illustrate the significant contribution of Fe-P to the endogenous P in sediments, it critically reviews the extraction, detection and quantification methods of sedimentary Fe-P, as well as their advantages and disadvantages. It also introduces the characteristics and distribution patterns of Fe-P in wetland ecosystems. Subsequently, the impacts of different factors are further analyzed, such as physical and chemical properties like temperature and dissolved oxygen, biological factors such as plants and benthic animals, and the composition of sediments on the release and migration processes of Fe-P. In addition, this work focuses on the interaction between Fe-P and organic matter in sediments, such as algae-derived organic matter and humic acid, as well as emerging contaminants like microplastics and antibiotics. This work looks forward to the future research of Fe-P in wetland sediments, with the hope of providing references for the regulation and management of wetland eutrophication status.