Sorption of barium on kaolinite, montmorillonite and chlorite

The sorption characteristics of the Ba2+ ion on kaolinite, montmorillonite and chloritetype clays were studied using the batch method. Barium-133 was used as a tracer. The Ba2+ ion concentrations ranged from 10-8 to 10-5 mol l-1; synthetic groundwater was used and the grain size of all the solid particles was <40 μm. About 6, 8 and 12 d of shaking were necessary to reach equilibrium for chlorite, kaolinite and montmorillonite, respectively. The sorption isotherms were described best by Freundlich and Dubinin - Radushkevich type isotherms. Sorption was predominantly reversible for kaolinite and partly reversible for montmorillonite and chlorite.