Chloride/sulfate exchange on anion resins. Kinetic investigations. Chemical control in selective exchanges

Rate determinations for the Cl^-/SO⁼₄ exchange on anion resins in very diluted systems (1 ÷ 6 × 10^-3N), where resin selectivities for the divalent ion are drastically raised by the electroselectivity effect, show convincing evidence that the chemical reaction rate on fixed charges controls the overall process kinetics. Activation energies, in particular, (up to 16.83 kcal/eq) are definitely out of the range for usual diffusion-controlled kinetics.A spherically-symmetrical diffusion model with a billiard-ball-like mechanism of site-to-site jumping of ions inside the resin is suggested.