title: Sonophotocatalytic inactivation of E. coli using ZnO nanofluids and its mechanism.
abstract: The present study evaluated inactivation efficiency of a sonophotocatalytic process using ZnO nanofluids including ultrasonic parameters such as power density, frequency and time. The result showed that inactivation efficiency was increased by 20% when ultrasonic irradiation was combined with photocatalytic process in the presence of natural light. Comparison of inactivation efficiency in photocatalytic, ultrasonic and sonocatalytic processes using Escherichia coli as a model bacteria identified that inactivation efficiencies are shown in the following order: ultrasonic irradiation<sonocatalysis<photocatalysis<sonophotocatalysis. Furthermore, inactivation mechanism of sonophotocatalysis was proposed. Studies of reactive oxygen species (ROS) and zinc ions (Zn2+) release evaluation revealed that ROS play a key role in bacterial inactivation rather than Zn2+. Permeability of outer membrane (OM) and inner membrane (IM) of E. coli bacterial cells were studied and exhibited that sonophotocatalysis increased the permeability of OM and IM significantly. The enhanced bacterial inactivation effect in sonophotocatalytic process contributed to acoustic cavitation, sonocatalysis of ZnO and sonoporation phenomenon.
authors: Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing 100083, PR China; School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, PR China. Electronic address: linglingzhangll@hotmail.com.
authors: Lingling
authors: L
authors: Zhang
authors: Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing 100083, PR China; School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
authors: Huan
authors: H
authors: Qi
authors: Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing 100083, PR China; School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
authors: Zhengxu
authors: Z
authors: Yan
authors: School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
authors: Yu
authors: Y
authors: Gu
authors: School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
authors: Weiqiang
authors: W
authors: Sun
authors: Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing 100083, PR China; School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
authors: Abraham Amenay
authors: AA
authors: Zewde
mesh_terms: D002384:Catalysis; D002463:Cell Membrane Permeability / Q000187:drug effects; D004926:Escherichia coli / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D050296:Microbial Viability / Q000187:drug effects*; D049329:Nanostructures / Q000737:chemistry*; D055668:Photochemical Processes; D017382:Reactive Oxygen Species / Q000378:metabolism; D000069453:Ultrasonic Waves; D015034:Zinc Oxide / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D017382:Reactive Oxygen Species; D015034:Zinc Oxide
keywords: Inactivation; Inactivation mechanism; Nanoparticles; Sonophotocatalytic; Ultrasonic irradiation; ZnO