Competitive sorption of metal ions from binary sulfate solutions with solvent-impregnated resins

Equilibrium and kinetics for the sorption of Cu(II) and Zn(II) from binary sulfate media with macroporous resins containing di(2-ethylhexyl)phosphoric acid (D2EHPA) were studied and compared with those obtained in the single systems. Experiments were performed as a function of aqueous pH, the concentration ratio of metal ions in the aqueous phase, and the concentration of D2EHPA in the resin phase. The rate of sorption was determined using initial rate technique by the Elovich equation. It was shown that the sorption equilibrium of one metal was hardly affected by the presence of the other. However, the sorption rate obtained in the binary systems was always less than that in the single systems. The separation factors based on equilibrium and kinetic aspects were obtained. Finally, the competitive effect in rates was discussed in terms of sorption mechanism.