Effect of Ozone Micronano Bubbles on the Removal of Infectious Pathogens in Contaminated Water: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis

The present study was performed to explore the bactericidal effect of ozone micronano bubbles (OMNBs) against Pseudomonas aeruginosa, Escherichia coli (as gram-negative bacteria), Enterococcus faecalis, and Staphylococcus aureus (gram-positive bacteria). The effects of conventional ozonation (CO) or macrobubbles were also investigated for comparison. Three rates of ozone (10, 5, and 1.7 g/h) in both forms (OMNB and CO) were employed in different time contacts. Samples were collected at different contact times. The most significant bactericidal effect of OMNB was observed in P. aeruginosa and S. aureus at 5 g/h ozone, which killed 100% of these bacteria after 8 and 5 min, respectively, whereas the kill times by CO at the same rates were 120 min for P. aeruginosa and 90 min for S. aureus, E. coli, and E. faecalis showed the same pattern of kill time, 60 and 60 min by CO and 3 and 2 min by OMNB, respectively. Results showed that the removal efficiency was significantly increased compared to the ordinary ozonation at the same ozone rates. According to the results of this study, disinfection of water contaminated with these bacteria can be effectively performed using OMNBs to accelerate and increase the efficiency of the disinfection process. The results may open a new horizon to disinfect medical and food processing instruments and surfaces more effectively without remaining residuals and harm to the environment.