Phosphorus adsorption on natural sediments: Modeling and effects of pH and sediment composition

The effect of pH in a wide range on adsorption process was investigated and H2PO4− was presumed to be the preferential sorption species in overall sorption process. The fact that the amount of P sorbed and zeta potential of sediment particles have no necessary relationship reveals that a strong contribution to the P binding still comes from a ligand-exchange process on the Me-OH2+ and Me-OH sites rather than electrostatic attraction. In addition, the influence of oxidation-reduction potential (ORP) was investigated and discussed and the dual nature of sediments as a pool or source of P in natural waters was evaluated in site T1-T4.