Ionic adsorption on variable charge mineral surfaces. Theoretical charge development and titration curves

Abstract

A completely general theory is presented which can be used to describe both anion and cation adsorption on amphoteric oxide surfaces. It takes account of the fact that both the surfaces and adsorbing species are charged and that the surfaces change their charge when ionic adsorption takes place. The theory is applicable to both specific and non-specifically adsorbed ions. It is shown to account for the pH dependent charge curves of goethite, silica and two tropical soils.