HiGee-intensified ozonation for enhanced inactivation of waterborne antibiotic-resistant bacteria.

Waterborne antibiotic-resistant bacteria (ARB) threaten the environment and human health, while conventional ozonation exhibits limited inactivation efficiency. To overcome this limitation, this study applied high-gravity technology (HiGee) to enhance ozone mass transfer and ARB inactivation. HiGee technology inherently possesses mechanical inactivation capability. The HiGee-intensified ozonation (HiGee-O3) process achieved 5.3-log inactivation within seconds, approximately tenfold higher than that obtained in a conventional stirred-tank reactor. Process parameters and co-existing substance had significant effect on bacterial inactivation. Radical scavenging experiments suggested that direct molecular ozone oxidation dominated the inactivation, while ·OH-mediated oxidation played a secondary role. Microscopic and spectroscopic analyses revealed that oxidative damage of membrane lipids, proteins, carbohydrates, and nucleic acids, resulting in irreversible cellular damage and bacterial inactivation. Overall, the synergistic effects of shear-induced physical disruption and ozone chemical oxidation actions provided a facile and potent process for curbing antibiotic resistance in the water environment.