Description of ion-exchange dynamics at an isothermal supersaturation in the presence of colloid particles on the surface of sorbent granules

The hypothesis that an isothermal supersaturation of the solution in ionite s is accompanied by the formation of a layer of colloid particles at the su rface of ionite grains that hampers ion exchange and stabilizes the solutio n is examined. This assumption was used to obtain an expression for describ ing the density of the layer as a function of the concentrations of the com ponents of the solution. The kinetic coefficient of ion exchange was expres sed through the density of the surface layer of particles. A model of the p rocess under study was developed and tested in predicting experimental resu lts; a close agreement between theoretical and experimental values was achi eved.