Static and kinetic studies of the adsorption/desorption of H⁺ and OH^- ions on alumina in aqueous NaNO₃ solution

The adsorption/desorption of H⁺ and OH^- ions under static conditions on to alumina in aqueous NaNO₃ solution was studied at 30°C by potentiometric titration and calculations undertaken using the triple layer model (TLM). Intrinsic dissociation constants and intrinsic complexation constants at 30°C were used to calculate surface charge density, surface potential and surface species as a function of pH and ionic strength (I). Related adsorption/desorption studies of H⁺ and OH ions under dynamic conditions on to alumina in aqueous NaNO₃ solution were studied by means of the concentration-jump technique. Mechanistic information regarding H⁺ and OH^- ion adsorption/desorption on to alumina was discussed using the experimental data in conjunction with the TLM.