Green rusts as a new solution to sequester and stabilize phosphate in sediments under anoxic conditions and their implication for eutrophication control

•GRs can rapidly adsorb phosphate from anoxic waters with high adsorption capacities.•GRs can effectively sequester P against interfering ions and soil particles.•The presence of P can in return stabilize GRs against oxidation.•The release of P is efficiently restricted from sediment column by GRs.•Surface anionic exchange is the major mechanisms governing P sequestration by GRs.