Synergistic Piezo-Catalytic Inactivation of Bacteria by Dual-Frequency Ultrasound (120 + 1700 kHz) Using Persulfate and ZnO Nano- and Microparticles

Dual-frequency ultrasound (DFUS) coupled with sonocatalysts has emerged to be an advanced tool for antimicrobial applications in medicine but remains scarcely studied water disinfection. In the present work, we first integrated high-frequency DFUS (120 + 1700 kHz), persulfate (S2O82−) and ZnO nano- (50 nm) microparticles (1 μm) eradicating Escherichia coli Enterococcus faecalis synthetic water. For E. coli, efficiency of DFUS-based processes can ranked as follows: < DFUS/ZnO DFUS/S2O82− DFUS/ZnO/S2O82−. A similar DFUS/ZnO/S2O82− was found more resistant faecalis. absence persulfate, performance 1 μm higher than that observed 50 nm inactivating via kHz/ZnO processes. synergy terms 5-log (total) reduction S2O82−/ZnO-based systems, being (synergistic coefficient = 1.8–3.0). The synergistic effect proposed driven by boosted generation reactive oxygen species sonoporation. This study opens prospects development novel piezo-catalytic systems efficient