Cu(II) assisted peroxymonosulfate for antibiotic resistant bacteria inactivation: A potential disinfection technology in swimming pool

Xiaohui Lu; Yiwei Chen; Huiyuan Chi; Chendong Zhao; Wei Qiu; Jun Ma; Say Leong Ong; Jiangyong Hu

doi:10.1016/j.scitotenv.2023.162755

Cu(II) assisted peroxymonosulfate for antibiotic resistant bacteria inactivation: A potential disinfection technology in swimming pool

Sci Total Environ. 2023 Jun 10:876:162755. doi: 10.1016/j.scitotenv.2023.162755. Epub 2023 Mar 11.

Authors

Xiaohui Lu¹, Yiwei Chen², Huiyuan Chi³, Chendong Zhao⁴, Wei Qiu⁵, Jun Ma⁵, Say Leong Ong⁶, Jiangyong Hu⁷

Affiliations

¹ State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; College of Environmental Science, Sichuan Agricultural University, Chengdu 611130, China.
² NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, Singapore 117411, Singapore.
³ Department of Civil & Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576, Singapore.
⁴ Department of Civil & Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576, Singapore; College of Environmental and Resource Science, Zhejiang University, Hangzhou 310058, China.
⁵ State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
⁶ NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, Singapore 117411, Singapore; Department of Civil & Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576, Singapore.
⁷ NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, Singapore 117411, Singapore; Department of Civil & Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576, Singapore. Electronic address: ceehujy@nus.edu.sg.

PMID: 36907423
DOI: 10.1016/j.scitotenv.2023.162755

Abstract

Alternative disinfection technology to chlorination is required to control the risk of antibiotic resistance in swimming pools. In this study, copper ions (Cu(II)), which often exist in swimming pools as algicides, were used to activate peroxymonosulfate (PMS) for the inactivation of ampicillin-resistant E. coli. Cu(II) and PMS showed synergistic effects on E. coli inactivation in weak alkaline conditions, obtaining 3.4 log inactivation in 20 min with 10 μM Cu(II) and 100 μM PMS at pH 8.0. Quenching experiments indicated that radicals (i.e., OH and SO₄^-) were not the main disinfectors for E. coli inactivation. Based on the structure of Cu(II) and density functional theory calculations, the Cu(II)-PMS complex (Cu(H₂O)₅SO₅) was recommended as the active species for E. coli inactivation. Under the experimental conditions, the PMS concentration had a greater influence on E. coli inactivation than the Cu(II) concentration, possibly because increasing PMS concentration accelerates ligand exchange reaction and facilitates active species generation. By forming hypohalous acids, halogen ions could improve the disinfection efficiency of Cu(II)/PMS. The addition of HCO₃^- concentration (from 0 to 1.0 mM) and humic acid (0.5 and 1.5 mg/l) did not significantly inhibit the E. coli inactivation. The feasibility of adding PMS to waters containing Cu(II) for the inactivation of antibiotic-resistant bacteria was validated in actual swimming pool waters, where 4.7 log inactivation of E. coli was achieved in 60 min.

Keywords: ARB; Copper; Disinfection; Metal-PMS complexes; PMS; Swimming pool water.

MeSH terms

Anti-Bacterial Agents* / pharmacology
Bacteria
Disinfection
Escherichia coli
Swimming Pools*

Substances

Anti-Bacterial Agents
peroxymonosulfate