Sorption behavior of thorium(IV) onto activated bentonite

Activated bentonite was obtained from acid activation and purification of raw bentonite, sorption of Th(IV) onto activated bentonite was studied by batch experiments. Characterization of activated bentonite and sorption behavior of Th(IV) demonstrated that Th(IV) could quickly absorbed on activated bentonite, and kinetic process fitted well with the pseudo-second-order model. Sorption percentage of Th(IV) on activated bentonite strongly depended on pH, background anion, ionic strength and temperature, which indicated surface complexation was the main sorption mechanism, physisorption and ion-exchange as secondary factors also participated in sorption processes. The results showed activated bentonite was an efficient material for Th(IV) sorption.