Removal of Co-60 and Zn-65 from a solution containing sodium salts by Dowex A-1

Removal of 60Co and 65Zn from aqueous solution in a column by the chelating resin Dowex A-l has been studied in its relation to pH, to the concentration of sodium salts added to the influent and to the flow-rate of the influent. It is shown that the decontamination factors (DF) of 60Co and 65Zn both increase consistently with pH between 3.5 and 5.0, beyond which theDF falls back. In relation to sodium salt concentration, the DF value decreases consistently with increasing concentration in the range of 0.1∼1.0N, above which, further addition of sodium salts has no further effect. The DF value is completely independent of flow-rate of the influent in range of 16∼160hr−1 space velocity. It is, further, very little affected by differences in effluent volume, in the range from 6.7 to 1.3×l03 bed volumes. For the regeneration of the resin, about 99.9% of 60Co or 65Zn is removed from the resin by at least 3 bed volumes of 0.1 M EDTA or 0.1 M NTA used as regenerating solution.