Assessing the effectiveness and mechanisms of Fe/PS, Fe/H2O2, and O3 treatment for water disinfection: Spotlight on VBNC bacteria

  • J Environ Sci (China). 2025 Jun:152:389-400. doi: 10.1016/j.jes.2024.05.023.
Zheng Qi  1 ,  Zaihui Huang  2 ,  Chunguang Liu  3
Affiliations
  • 1. School of Environmental Science and Engineering, Laboratory of Marine Ecological Environment in Universities of Shandong, Shandong University, Qingdao 266237, China; Environmental Simulation and Pollution Control State Key Joint Laboratory, School of Environment, Tsinghua University, Beijing 100084, China.
  • 2. School of Environmental Science and Engineering, Laboratory of Marine Ecological Environment in Universities of Shandong, Shandong University, Qingdao 266237, China.
  • 3. School of Environmental Science and Engineering, Laboratory of Marine Ecological Environment in Universities of Shandong, Shandong University, Qingdao 266237, China; Qingdao Key Laboratory of Marine Pollutant Prevention, Shandong Key Laboratory of Environmental Processes and Health, Shandong University, Qingdao 266237, China. Electronic address: [email protected].
PMID: 39617561 DOI: 10.1016/j.jes.2024.05.023
Abstract

Advanced oxidation processes (AOPs) exhibit significant potential for water disinfection due to their generation of large quantities of highly oxidizing free radicals. However, the neglect of viable but nonculturable (VBNC) cells obscures their true disinfection efficacy and potential environmental health risks. Therefore, the study evaluated the disinfection effectiveness and mechanisms of typical AOPs, including Fe/H2O2, Fe/persulfate (PS), and O3, from the perspective of the production of VBNC bacteria. The results indicate that Fe/PS exhibits the strongest Bacterial inactivation rate (99.94%), and the cells lose their ability to reactivate. Fe/H2O2 and O3 induce more cells to enter the VBNC state compared to Fe/PS. Moreover, different AOPs result in varying levels of free radical production and utilization efficiency, with SO4•- and O3 exhibiting greater selectivity in deactivating bacteria compared to HO•. The inhibition of VBNC bacteria production by Fe/PS treatment may be attributed to the combined action of HO• and SO4•- on Microorganisms, leading to oxidative stress and metabolic disruption in bacteria through the inhibition of biofilm formation and aminoacyl-tRNA biosynthesis (p < 0.05), thereby causing direct Bacterial death rather than entry into the VBNC state. In contrast, Fe/H2O2 and O3 result in the upregulation of the metabolism of alanine, aspartate, and glutamate, as well as styrene degradation capacity by the bacteria, leading to the production of more VBNC bacteria. Overall, the study offers insights into mitigating potential biological risks in water disinfection and developing environmentally friendly and efficient disinfection technologies.

Keywords
Advanced oxidation processes; Disinfection; Oxidative stress; Reactive oxygen species; Viable but nonculturable cells.
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