The Adsorption of Zinc(II) on Anion-exchange Resins. II. Stoichiometry, Thermodynamics, Loading Studies, Dowex-2 Adsorption and Factors Influencing the Rate of the Adsorption Process

Abstract

The adsorption of macroscopic amounts of zinc(II) on Dowex 1-XB chloride has been studied at room temperature; the chloride content of the resin doubles with the equivalent adsorption of zinc(II) species. The adsorption of tracer zinc(II) on Dowex 1-X8 chloride from LiCl and HC1 solutions at 0.25 and 49 deg has been studied, and the results indicate the presence of a secondary process resulting in apparent resin adsorption at high LiCl concentrations. Loading studies indicate that the equivalent capacity of Dowex l for zinc(II) chloro- complex ions is the same as for chloride ion, thus rendering unlikely the supposition that the adsorption process is other than ion exchange with the resin functional groups. The adsorption of tracer zinc(II) on Dowex 2 from HCl and LiCl solutions, while somewhat less, is substantially the same as on Dowex 1. The influence of resin mesh and amount, the concentration of various constituentc; in the solution phase, and solvent composition on the rate of the adsorption and desorption processes has been studied together with the rate of exchange of radiozinc(II) between resin and solution phases. (auth)