Mechanisms of colloid sorption on mineral surfaces: a RBS study

Abstract A novel experimental approach is presented to assess the mechanisms of colloid sorption. In this technique, centimetre-sized sections of individual minerals (silica, muscovite) were contacted with aqueous solutions containing colloidal particles. After mineral/solution separation, the solid surface was analysed by Rutherford backscattering spectrometry (RBS). Information on the amount and depth distribution of retained colloids was obtained. This versatile technique provides insight into the mechanisms of retention and the identification of controlling properties (charge and size of colloids, surface state of minerals).