| Abstract: | A previously published bidisperse pore model that considers in turn ion interdiffusion in macro- and micro-pores as competitive and step-by-step processes was evaluated. The ion exchange rate of H+/Ni2+ on gel and macroporous strong acid resins was measured under conditions favoring a particle diffusion controlled mechanism. The interdiffusion coefficients were obtained using a bidisperse pore and quasi-homogenous resin phase kinetic models, respectively. The overall rate of H+/Ni2+ exchange on the macroporous resin is lower than in the gel resin. It was shown that ion interdiffusion in the micropores of the porous resin could also be important. |
