Th(IV) adsorption onto titanium tetrachloride modified sodium bentonite

Ti(OH) 4 and TiCl 4 modified bentonite (Ti–Na-bent) were applied in the removal of Th(IV) from aqueous solution. Effect of different factors such as pH, contact time, temperature, initial concentration of Th(IV) and efficiency of them for thorium adsorption are investigated. Ti–Na-bent showed high adsorption capacity (q m = 231.37 mg/g) and quick adsorption kinetics at lower pH. The adsorption mechanisms involved are: (1) Th 4+ , [Th(OH) 4− n ] n + complexed on the outer-sphere of Na-bent and Ti–Na-bent. (2) Ion exchange between Th 4+ , [Th(OH) 4− n ] n + and exchangeable cations of Na-bent and the H on the hydroxyl group of Ti(OH) 4 . Ti–Na-bent manifested high adsorption capacity for Th(IV), good acid resistance and long-term adsorption stability.