Dechlorination of Chloride–Sulfate Solutions Using Ozone

Kinetic characteristics are determined for the release of chlorine during the oxidation of chloride ion in solutions Na⁺–H⁺–HSO\(_{4}^{ - }\)–Cl⁻, Mg²⁺–H⁺–HSO\(_{4}^{ - }\)–Cl⁻, Zn²⁺–H⁺–HSO\(_{4}^{ - }\)–Cl⁻, Cu²⁺–H⁺–HSO\(_{4}^{ - }\)–Cl⁻, Fe³⁺–H⁺–HSO\(_{4}^{ - }\)–Cl⁻, Mg²⁺–H⁺–Cl⁻, and Ca²⁺–H⁺–Cl⁻. With similar experimental parameters, the rate of the reaction acquires considerably different values, depending on the nature of the added salt. This is due to the possible catalysis of the reaction between O₃ and the Cl⁻(aq) cations of some metals; the formation of chloride and sulfate metal complexes, which alters the actual concentrations of reagents; and a change in the solubility of ozone. The solubility of ozone, the values of the Henry constant, and the Sechenov coefficient are found for aqueous solutions of zinc sulfate and magnesium sulfate with concentrations of 0–1 M at temperatures of 20 and 25°C.