Sorption of CMID-containing cations on strongly basic anion exchangers

It is shown that strongly basic anion exchangers AV-17 and Varion-AD in definite conditions are able to retain Cr(III)-containing ions from Cr(III) sulfate solution. It is found that the sorption of Cr(III)-containing ions on the polymers is essentially dependent on the pH, temperature, and Cr(III) sulfate concentration. The maximum temperature dependence of sorption was found to be about 60 degrees C. The sorption isotherms are well described by Langmuir's equations. The sorption kinetics is determined by the diffusion of Cr(III)-containing ions into polymer's phase. It is assumed that the Cr(III)-containing ions are retained through formation, in polymer's phase, of the jarosite-type mineral compounds: R4N[Cr-3(OH)(6)(SO4)(2)], H3O[Cr-3(OH)(6)(SO4)(2)], and K[Cr-3(OH)(6)(SO4)(2)]. For comparison of sorptional capacities, the sorption of Cr(III)-containing ions was determined on different cation and anion exchangers. (c) 2006 Wiley Periodicals, Inc.