Thermodynamic Equilibrium between an Ionite's Gel Part and a Simple-Salt Solution with Allowance for Water Dissociation

When solving an ion-exchange equilibrium problem it is usually taken into account that the ionite, according to a two-phased model, comprises microphases of a gel and an equilibrium solution. The question of equilibrium in this case involves the necessity to take into account not only ions of salt contained in an aqueous solution, but ions of hydrogen and hydroxyl, which emerge in the water dissociation process, as well. Setting up such a problem is dictated, for example, by the application of electrodialysis for the production of deeply-desalinated water. In the work, for a solution of a simple salt, relations are established, which allow one to compute complete ionic composition of phases of solution and gel on the basis of specified values of concentrations of cations and anions of salt in solution.