ADSORPTION OF PHOSPHORUS IN SATURATED SLAG MEDIA COLUMNS

Adsorption of phosphorus (P as phosphates) in saturated slag media (du st and cake) columns was studied to assess the slag media's capability in removing P from wastewater. Prior to the experiments, slag media w ere completely washed to rinse off the soluble metal ions which are ge nerally responsible for forming insoluble precipitates. Experimental d ata revealed that the adsorption capacities of washed slag media are s till much higher than that of a sandy roam soil.Two dynamic models wer e tested for simulating the adsorption behavior of phosphorus in colum ns packed with slag media. The model employing the intraparticle trans port through surface diffusion is successful, while a simplified model based on the linear driving force approximation (LDFA) could not pred ict the column behavior properly at low concentrations, particularly o n the cake slag. (C) 1997 Elsevier Science B.V.