Catalytic wet peroxide oxidation (CWPO) is a novel, alternative technology to conventional disinfection methods that are widely used to control microbial parameters in drinking water. To assess its effectiveness, new studies revealing the kinetics of MS2 coliphage inactivation by CWPO technology are required. This investigation therefore aimed to perform mathematical modelling of MS2 inactivation through CWPO technology activated by an Al/Fe-pillared clay catalyst (Al/Fe-PILC) in the presence of a synthetic surrogate of dissolved natural organic matter. The inactivation constant was obtained from two different statistical approaches, and the experimental data were better fitted to the pseudo-first-order Chick-Watson model in which the inactivation rate is constant. For this model, the maximum inactivation rate was k = 0.1648 min-1, which was achieved in the MS2-3 catalytic test using an initial mass ratio of peroxide to active iron (Feact) of 1.2 mg H2O2/mg Feact. To estimate the inactivation rate due to reactive oxygen species (ROS), we supposed that the inactivation constant depends on both ROS and Feact. In this case, the maximum inactivation rate due to ROS was kr = 2.4 × 10-9 min-1 (using 1.17 mg H2O2/mg Feact), which was achieved in the MS2-10 trial; both cases led to the conclusion that the optimal initial ratio of peroxide to active Fe in the catalyst in CWPO activated by Al/Fe-PILC was close to 1.2 mg H2O2/mg Feact. These kinetic studies showed that rapid inactivation takes place very early in the reaction, followed by slow inactivation during the remaining period of the recorded reaction time. This research revealed the strong potential of CWPO technology to improve microbiological parameters in drinking water due to the high catalytic performance in the heterogeneous Fenton reaction displayed by Fe sites incorporated in the Al/Fe-PILCs.
Keywords: Al/Fe-PILC; CWPO; Inactivation; Kinetics; MS2 coliphage; Mathematical modelling.