Removal of radiocobalt from EDTA-complexes using oxidation and selective ion exchange

摘要

Methods for the removal of radiocobalt from an ethylenediaminetetraacetic acid (EDTA) complexnof Co(II) (aqueous solution containing 10mM Co(II) and 10mMor50mM EDTA traced with 57nCo) arenpresented. The studies examined a combination of different oxidation methods and the sorptionnofn57nCo on a selective inorganic ion exchange material, CoTreat. The oxidation methods usednwere ultraviolet (UV) irradiation with and without hydrogen peroxide (H2O2), as well as ozonationnalone or in combination with UV irradiation. Also, the possible contribution of Degussa P25 TiO2nphotocatalyst to degradation of EDTA was studied. The best results for the equimolar solution ofnCo(II) and EDTA were achieved by combining ozonation, UV irradiation, Degussa P25 TiO2 andnCoTreat, with approximately 94% sorption ofn57nCo. High values for the 57nCo sorption were alsonachieved by ozonation (,88%) and UV irradiation (,90%) in the presence of CoTreat and DegussanP25 TiO2. A surplus of EDTA over Co(II) was also tested using 10mM Co(II) and 50mM EDTA.nOnly a slight decrease, to ,88% sorption ofn57nCo, was detected compared to the value (,90%)nobtained with 10mM EDTA.