Oxidative paraben removal with chlorine dioxide: Reaction kinetics and mechanism
This study investigated the reactivity and mechanism of paraben oxidization by chlorine dioxide. Degradation kinetics of methylparaben (MeP) and propylparaben (PrP) followed pseudo-first-order kinetics, and were studied in a pH range of 4.0–7.0 at 15 ± 1 °C. The k app values were 84.3 M −1 ·s −1 and 83.2 M −1 ·s −1 for MeP and PrP, respectively, when pH value was 5.0 and the temperature was 15 ± 1 °C. The rate constants depended on the solution pH, temperature, humic acid, and HCO 3 – concentrations. At pH values of 4–5.0, k app increased slowly, while at a pH value of 7.0, k app increased rapidly. The reaction rate constants increased with increasing temperature. Furthermore, the reaction rate was inhibited by humic acid addition, while the reaction rate increased after addition of HCO 3 – . Two main degradation products were identified by GC–MS and the reaction pathways were proposed.
危险品化学品经营许可证（带存储）