Adsorption behaviour of 226Ra and 210Pb onto thermally treated forms of bentonite

This study investigated the sorption selectivity of bentonite and its thermally treated forms, at 150, 300 and 600 °C, for 226 Ra and 210 Pb. Characterisation of adsorbents was performed by applying Fourier transform infrared spectroscopy and a scanning electron microscope. Adsorption data showed the materials illustrated comparable behaviour for 210 Pb, but varied when chemical containments existed in solution. Bentonite heated at 600 °C (B-600) was the best adsorbent for 226 Ra. Influence of macro contaminants revealed K + was the greatest inhibitor for 226 Ra and Ca 2+ for 210 Pb. The data conclude B-600 would be the preferable mineral for constructing engineered disposal facilities.