Morphological characteristics and chemical behaviour of phosphorus at the sediment–water interface in wetland

Abstract

AbstractThe content and adsorption capacity of phosphorus in the surface and bottom sediments of the karst wetland were monitored for 2 months. The results indicated that the total phosphorus concentration in the sediments varied from 217.15 to 1511.84 mg kg−1 and 353.64 to 1650.26 mg kg−1 in summer and autumn, respectively. The adsorption kinetics and isotherm of phosphorus by wetland sediments were systematically studied. The adsorption isotherm conformed well to the Langmuir isotherm model. The maximal adsorption capacity (Qmax), background adsorbed phosphorus (NAP), and equilibrium concentrations (EPCe) in sediments were strongly affected by Eh, pH, the content of inorganic phosphorus (IP), and organic phosphorus (Or‐P). The results of this research will shed light on understanding the biogeochemistry behaviour of phosphorus at the sediment–water interface in karst wetland and the water purification mechanism in wetland sediments on a global scale.