Hydrogen peroxide-assisted pasteurization: An alternative for household water disinfection

Abstract

Decentralized treatments applied at the household level may be alternatives to positively impact global health. Pasteurization is a conventional disinfection method and efforts have been made to increase its efficiency and productivity in point-of-entry (POE) applications. To overcome limitations associated to this practice, we hypothesized that including oxidation prior to pasteurization would improve the treatment. This research aimed to evaluate the performance of hydrogen peroxide-assisted pasteurization and effects of H2O2 concentration and temperature organized by a full factorial experimental design. At optimal conditions, >9.3 log10 inactivation of Escherichia coli and >5.8 log10 Phi X174 bacteriophage were obtained. Observed values were modeled as empirical equations for E. coli and phage inactivation (R2 = 0.76 and 0.72, respectively). Temperature did not lead to significant differences in H2O2 residual, which is favorable for practical implementation. Synergistic effects were found for E. coli, and inactivation of Phi X174 tops results obtained by individual disinfection by pasteurization and H2O2 oxidation. Our study also suggests H2O2-assisted pasteurization increases oxidation potential, inferred by cell lysis and protein removal. Additionally, analyzing disinfection and H2O2 residuals during temperature ramp time endorsed that inactivation might happen at lower temperatures, and stability of H2O2 may provide a safer setup when heat sources cannot guarantee pasteurization to occur. Broadly, our research underscores potentials of H2O2-assisted pasteurization and, although we recommend further assessments considering pathogens, as well as case studies for specific scenarios, we believe H2O2 may improve performance and resilience of classic disinfection by pasteurization as a POE solution.