Enhanced inactivation of Escherichia coli by ultrasound combined with peracetic acid during water disinfection

Yun Bai; Chunhai Shi; Yuanhang Zhou; Yingying Zhou; Haocheng Zhang; Ruiting Chang; Xueli Hu; Jiawei Hu; Chuanyao Yang; Kedi Peng; Ping Xiang; Zhi Zhang

doi:10.1016/j.chemosphere.2023.138095

Enhanced inactivation of Escherichia coli by ultrasound combined with peracetic acid during water disinfection

Chemosphere. 2023 May:322:138095. doi: 10.1016/j.chemosphere.2023.138095. Epub 2023 Feb 7.

Authors

Yun Bai¹, Chunhai Shi², Yuanhang Zhou¹, Yingying Zhou¹, Haocheng Zhang¹, Ruiting Chang¹, Xueli Hu¹, Jiawei Hu¹, Chuanyao Yang³, Kedi Peng¹, Ping Xiang⁴, Zhi Zhang⁵

Affiliations

¹ Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing, 400045, China.
² Northwest China Municipal Engineering Design and Research Institute, Lanzhou, 730000, China.
³ Analysis and Testing Center, Chongqing University, Chongqing, 400045, China.
⁴ Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing, 400045, China. Electronic address: Xiangping74@cqu.edu.cn.
⁵ Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing, 400045, China. Electronic address: zhangzhicqu@cqu.edu.cn.

PMID: 36758811
DOI: 10.1016/j.chemosphere.2023.138095

Abstract

Peracetic acid (PAA) is a desirable disinfectant for municipal wastewater because of its potent disinfection performance and limited toxic by-products. This study explored the efficiency and mechanism of Escherichia coli inactivation by PAA combined with ultrasound simultaneously (ultrasound + PAA) or (ultrasound → PAA) sequentially. The result showed that 60 kHz ultrasound combined with PAA sequentially (60 kHz → PAA) had excellent inactivation performance on E. coli, up to 4.69-log₁₀. The result also showed that the increase of pH and humic acid concentration in solution significantly reduced the inactivation efficiency of 60 kHz → PAA treatment. We also observed that the increase of temperature was beneficial to the disinfection, while anions (Cl^-; HCO₃^-) had little effect. With 60 kHz → PAA, the PAA and the synergism between PAA and ultrasound played major contribution to the inactivation, which we assumed might be due to both the diffusion of PAA into the cells and the damage to the cytomembrane by ultrasound, as evidenced through the laser confocal microscopy (LSCM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The inactivation mechanism involved the destruction of cell membrane and loss of intracellular material. Empirically, 60 kHz → PAA was found to be effective for the inactivation of E. coli in actual wastewater, and the regrowth potential of E. coli treated by 60 kHz → PAA was significantly lower than that treated only by PAA.

Keywords: E. coli; Efficiency; Influencing factors; Mechanism; Ultrasound.

MeSH terms

Disinfectants* / pharmacology
Disinfection
Escherichia coli / metabolism
Peracetic Acid / pharmacology
Wastewater
Water Purification*

Substances

Peracetic Acid
Wastewater
Disinfectants