Comparative study on concentrating U (VI) as arsenazo-III complex on some ion exchangers from intermediate acidic solutions

The distribution of U(VI) between the cation exchanger dowex-50 W X 8, the anion exchanger AG-2 X 8 and the chelating resin chelex-100 and aqueous acidic solutions of arsenazo-III was investigated. The effect of the acidity and arsenazo-III concentration on the distribution of U (VI) between the three exchangers was studied. Chelex-100 was found to be very specific for the sorption of U(VI)-arsenazo-III complex as well as for arsenazo-III itself. The sorption of U (VI)-de complex on chelex-100 decreases with increasing the acidity of the arsenazo-III solutions within the studied range (0.5-1.5 N HCl). The results obtained also show that the sorption of U(VI) -arsenazo-III complex on chelex-100 is the highest compared to the other two exchangers under similar conditions. This high sorption of U(VI)-arsenazo-III complex on chelex-100 is attributed to ion association mechanism, where formation of salt-like compounds through reaction between the functional groups of the resin i.e. Iminodiacetic and the different acidic groups of U(VI)-arsenazo-III complex as well as the arsenazo-III. 4 figs