ABSTRACT
A detailed knowledge of the kinetics of ion exchange is important not only for economic employment of ion exchange materials in the laboratory and in industry but also for a better understanding of these processes in natural systems, as e.g., in the soil or in biological membranes. Usually, ion-exchanger materials are employed, which are homogeneous with respect to quantities which affect the rate of ion exchange, are selected for such investigations to avoid complicating the derivation and validation of rate equations unnecessarily. The chapter outlines the derivation of the rate equation used subsequently for film diffusion controlled ion-exchange processes in homogeneous systems. It discusses the mixtures of ion-exchanger particles which differ in their kinetic properties to examine the consequences of heterogeneity.
