Evaluating the effectiveness of ion exchangers for the electrodeionization process

A method for the evaluating the performance of ion exchange resins in the electrodeionization process has been proposed. This method is based on the study of the ion exchange kinetics and involves experimental determination of three parameters: the particle size distribution, the ion-exchange capacity, and ion exchange rate constants. Using these parameters, ionic conductivity has been calculated, the value of which has been used for estimating the effectiveness of ion exchangers. Fourteen brands of cation exchange resins have been studied using the proposed procedure. It has been shown that the best grades are lightly crosslinked Amberlyst BD20 and Amberlyst 131WET. In addition, the “granulate”, a potential ion exchange packing for use in electrodeionization, composed of the ion exchange resin by 60% has been investigated. The rate of ion exchange on the best granulate sample has appeared to be 12 times lower than that on the best ion exchange resins.