Removal of metal pollutants (Cd,U) from pyhosphoric acid (PA) solutions by ion exchange: I Batch and column extractions

摘要

This paper presents the results of a series of batch and column sorption experiments to remove metal pollutants such as Cd(II) and UO_2(II) from PA solutions using ion exchange resins. Aminomethylphosphonic acid resin (Purolite S940) was found to be a potential one for uranium removal from PA solution. However, uranium loading on the resin was strongly influenced by the acid strength of the PA solution. The loaded uranium was quantitatively eluted with 1M Na_2CO_3. Diphonix~(TM) resin containing both sulphonic and gemdiphophonic acid groups was used for column removal of Cd(II) from PA solution. As we observed in the case of uranium, the acid concentration strongly influenced the sorption/elution behavior of Diphonix~(TM) resin for Cd(II). The results of Cd(II) removal were compared with those obtained using a commercial sulphonic acid type ion exchange resin Purolite CT-175.