The diffusion of H+ and Ni2+ ions in an inorganic cation-exchange matrix

The kinetics of sorption on zirconium hydrophosphates with various water contents was studied. The self-diffusion coefficients of Ni²⁺ and H⁺ and the effective diffusion coefficients of Ni²⁺ ions corresponding to the exchange Ni²⁺ → H⁺ were determined. The self-diffusion coefficients of ions in samples with an 85% water content were as high as 4.17 × 10^?11 m²/s (Ni²⁺) and 5.06 × 10^?10 m²/s (H⁺). Water loss caused by drying the sorbents resulted in a decrease in the rate of ion exchange.