Development of a data base for modelling adsorption of inorganics on iron and aluminum oxides

Although there is an abundance of data for equilibrium adsorption of inorganic ions on hydrous oxides and surface complexation models are capable of fitting the data with only a few adjustable parameters, these models have not been used in practice because of the lack of consensus as to the “best” model and the lack of a coherent compendium of equilibrium adsorption constants. To remedy this situation, a thermodynamic data base for inorganic adsorption is being developed from original data using a simple yet widely applicable model. The resulting data base can be included in general chemical equilibrium computer programs and used to predict adsorption (outside as well as within the range of calibrating data) in aqueous systems containing oxide surfaces. Both the model and the parameter extraction procedure are presented, and results for adsorption of some cations on hydrous ferric oxide are reported and discussed.