| Popis: |
Columns packed either with bentonite and quartz or only with quartz were used to investigate the sorption and desorption of U(VI) in the presence or absence of sulfate, carbonate, and phosphate at pH 6.5. A considerable difference in the breakthrough and desorption curves was revealed for columns with and without bentonite. With bentonite in the system considerable differences were obtained with respect to the presence of the ligands sulfate, phosphate, and carbonate. With sulfate a slight decline of uranium sorption was found, while phosphate enhanced sorption slightly. On contrary, carbonate suppresses uranium sorption to a high extent. Distinct differences were obtained for the desorption, however, in all experiments it could be shown that more uranium was desorbed than previously sorbed, indicating that the natural bentonite contained substantial amounts of uranium. |
