Adsorption characteristics of Eu(III) on colloidal bentonite particles in aqueous solution: impact of colloid concentration, pH, foreign ions, and temperature

The adsorption characteristics of Eu(III) on colloidal bentonite particles were investigated by batch experiments as functions of colloid concentration, pH, foreign ions, and temperature. Bentonite colloids displayed remarkable adsorption ability to Eu(III), the Eu(III) adsorption was significantly affected by solution chemistry. The Eu(III) adsorption increased with colloids concentration and pH increasing. Divalent cations (Ca2+, Mg2+ and Sr2+) and anions (Cl− and SO42−) inhibited Eu(III) adsorption, whereas PO43− greatly enhanced Eu(III) adsorption. High temperature was beneficial for Eu(III) adsorption, the adsorption process was a spontaneous endothermic process. The results suggested that colloids could acted as an efficient carrier for Eu(III) transport.