RES³T - Rossendorf Expert System for Surface and Sorption Thermodynamics

The adsorption of boric acid on magnetite and zirconium dioxide in aqueous suspensions has been characterized through electrokinetic measurements and potentiometric titrations. Both the pzc and the iep shift to lower pH values upon adsorption, remaining equal at all boric acid concentrations studied. From the shifts in pzc, values for the adsorption equilibrium constants are derived using the site-binding model and assuming that boron is placed in the zero plane rather than in the β-plane. The predictions of the model for the pH-dependence of adsorption are compared with available literature values.