Preparation and Sorption Properties of Cadmium Hexacyanocobaltate(III)

On the use of hexacyanocobaltates in the separation of caesium from radioactive waste solutions

“…The chemical stability of CoHCC in nitric acid makes it more advantageous than its ferrocyanide analogue where oxidation of the latter causes partial dissolution and disintegration [40,41]. The effective capacity of CoHCC for caesium was determined by repeated equilibration and has been found to be 1.01 meq g-1 dry CoHCC [38]. This capacity represents only 42% of the theoretical capacity (2.4 meq g-l) assuming that one Co 2 § ion of CoHCC is exchanged for two Cs § ions [6].…”

“…It has also been found that the presence of monovalent ions increases the sorption of radiocaesium. The relative effect of the monovalent cations can be arranged as follows: Na § = K* >NH +4 >>H + It is of interest to mention that the loading capacity of CdHCC at pH 12 has increased from 25 to 60 g Cs kg 1 CdHCC after being treated with sodium chloride solution 9 The distribution coefficient, kd, which determines directly the extent of caesium removal has been reported [39]. The results indicated the significant effect of pH as well as the treatment of CdHCC with sodium chloride on kd values.…”

“…The sorption properties of CdHCC [39] have been investigated. The results obtained indicated the enhancement of the sorption of caesium after treatment of CdHCC with sodium chloride solution of pH 12.…”

“…These cyano complexes form insoluble salts with the divalent transition metal ions. The composition and sorption capacity of the insoluble hexacyanoferrates(II, III) depend on the experimental conditions and the ratio of the reactants [25,[38][39][40]. There are many reviews dealing with this class of exchangers [15][16][17]41].…”