KINETIC MECHANISMS IN ION-EXCHANGE PROCESSES

The kinetic mechanisms for cationic and chelating ion exchange were in vestigated. The applicability of kinetic equations to fit experimental results was demonstrated using the pore diffusion and unreacted core models and two different experimental systems: K+ -Na+ in sulphonic re sins and metal-Na+ in iminodiacetic chelating resins. Microscopic obse rvations of intraparticle profiles in the case of metal-Na+ exchange s how that the unreacted-core model is adequate for describing such a pr ocess, allowing the calculation of intraparticle diffusivities.