Performance evaluation of ozonation for removal of antibiotic-resistant Escherichia coli and Pseudomonas aeruginosa and genes from hospital wastewater

Abstract

The performance of ozonation for the removal of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) using Escherichia coli and Pseudomonas aeruginosa carrying ARGs from hospital wastewaters was evaluated in this study. Bacterial inactivation was determined using plate count methods and real time PCR for ARG damage (Sul1, blatem, blactx, blavim and qnrS). The reduction rate of bacterial cells and ARGs was increased by different amounts of transferred ozone dose from 11 to 45 mg/L. The concentration of 108 cfu/ml bacteria was reduced to an acceptable level by ozone treatment after a 5 min contact time, Although the removal rate was much higher for concentrations of 106 cfu/ml and 104 cfu/ml bacteria. Overall, the tendency of gene reduction by ozonation from more to less was 16S rRNA > sul1 > blatem > blactx > qnrS > blavim. Given that plasmid-borne ARGs can potentially be transferred to other bacteria even after the disinfection process, our results can provide important insights into the fate of ARGs during hospital wastewater ozonation.

Inactivation of Bacteria and Residual Antimicrobials in Hospital Wastewater by Ozone Treatment

“…These results indicate that the susceptibility to ozone varies among bacterial species. The finding that ESBL-producing pathogenic bacteria, such as E. coli (pink pigment) and Klebsiella (dark blue pigment) exhibit a marked susceptibility to ozone and is consistent with previous reports [ 28 , 45 , 46 ] supports the proposal for the installation of an ozone treatment system in hospital wastewater tanks.…”

Application of Ozonation-Biodegradation Hybrid System for Polycyclic Aromatic Hydrocarbons Degradation

“…Thus, the concentration of ozone is an important factor that influenced this adverse effect on the bacteria. According to the literature reduction rate of Pseudomonas aeruginosa cells increased with the amount of transferred ozone dose increasing from 11 to 45 mg L −1 [ 45 ]. Ozonation with an ozone dose of 5 and 10 mg L −1 was not able to eliminate Pseudomonas from the secondary effluents of two wastewater treatment plants [ 46 ].…”

A sustainable waste-to-protein system to maximise waste resource utilisation for developing food- and feed-grade protein solutions

“…Ozonation is commonly used to treat wastewater containing ARGs and has been applied to solid wastes in previous works. 34–37 However, it requires tightly controlled conditions that are highly dependent on solid waste feedstock properties, such as pH, water content, particle size. 35 Furthermore, the impact on protein quality resulting from ozonation pre-treatment of OFMSW requires further investigation to assess the potential for integration into a waste-to-protein valorisation process system.…”