Mobility of Cr(VI) anions in the phase of the amphoteric inorganic ion exchanger

Abstract

The method of impedance spectroscopy has been used to investigate hydrogel and xerogel of hydrated zirconium dioxide containing Cr(VI) obtained from cation-and anion-substituted forms of an ion exchanger. It is shown that a complex composition of the amphoteric inorganic ion exchanger as well as protonization of its functional groups producing a substantial impact on the value of its electrical conductivity do not make it possible to assess mobility of sorbed ions. Nonetheless, the effective values of internal diffusion mobility of Cr(VI) may be obtained by the kinetic method: diffusion coefficients corresponding to the Cr(VI) → OH constitute 8.57 × 10−12−6.85 × 10−11 m2/s or hydrogel and 3.33 × 10−13−5.45 × 10−12 m2/s for xerogel depending on the sorbate concentration.