UO22+ sorption on bentonite

The capacity of bentonite and purified bentonite to remove UO22+ ions from aqueous solutions has been investigated, The UO22+ uptake in these clays was determined for 0.2 and 0.002M uranyl nitrate solutions. It was found that under these conditions (0.2M) the maximum UO22+ uptake was 1.010+/-+/-0.070 meq UO22+/g of bentonite and 0.787+/-0.020 meg UO22+/g of purified bentonite. In purified bentonite UO22+ sorption is irreversible up to 50 hours as no desorption was observed. Such is not the case in the natural bentonite. X-ray diffraction, thermal analyses, and transmission electron microscopy were used to characterize the solids. The uranium content was determined by neutron activation analysis.