Removal of Ca(II) and Mg(II) ions from solutions to sulfonic cation exchanger based on plasticized polyvinylchloride

The ion-exchange material was obtained by oxidation of the product of the interaction of polyvinyl chloride with an aqueous solution of calcium polysulfide. The structure of the resulting cation exchanger and metal-containing hybrid material was identified by IR spectroscopy and elemental analysis. The kinetics of absorption of metal ions in cation exchange resin was analyzed by using pseudo-first and pseudo-second order models. The rate constants in the adsorption process were calculated. According to the correlation coefficient, it was determined that the sorption process proceeds according to the laws of a pseudo-second order reaction. Based on the equilibrium sorption it was evaluated according to the isotherm models of Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich (D-R). The results showed that the absorption of Ca²⁺ and Mg²⁺ ions from aqueous solutions in cation exchange resin displays the best accordance with the Langmuir monomolecular theory. In addition, the results showed that the cation exchanger (PVC-SO₃H) effectively cleans river water from Ca²⁺ and Mg²⁺ ions for industrial enterprises.