{"title":"[Synergistic Disinfection Effects of Dual-wavelength Ultraviolet and Its Impact on Photoreactivation and Dark Repair].","authors":"Tian-Hong Zhou, Yuan-Fu Liang, Zhe Sun, Meng-Kai Li, Jia-le Wang, Wen-Tao Li, Wei-Wei Ben, Guo-Zhen Zhang, Zhi-Min Qiang","doi":"10.13227/j.hjkx.202401163","DOIUrl":null,"url":null,"abstract":"<p><p>Ultraviolet-C (UV-C) irradiation can effectively deactivate pathogenic microorganisms. The far UV-C (200-230 nm) and conventional UV-C (250-280 nm) can damage the proteins and nucleic acids of pathogenic microorganisms, respectively. The combination of far and conventional UV-C has the potential of synergistic inactivation. However, relevant studies remain limited owing to the lack of appropriate experimental setups. Therefore, this study established a mini-fluidic photoreaction system equipped with a KrCl excimer lamp and a low-pressure mercury lamp. This system could independently/simultaneously deliver stable 222 nm (far UV-C) and 254 nm (conventional UV-C) irradiations. Subsequently, the system was used to investigate the synergistic effect of dual-wavelength UV-C (the combination of 222 nm and 254 nm UV-C) on <i>Escherichia coli</i> (<i>E. coli</i>) inactivation and the subsequent impact on photo- and dark-reactivation. The results indicated that dual-wavelength UV-C had a significant synergistic effect on <i>E. coli</i> inactivation, with a synergistic coefficient up to 2.2. Additionally, comparing to 254 nm UV irradiation, the photo-reactivation of <i>E. coli</i> after dual-wavelength UV-C irradiation was weakened, with the maximum lg reactivation percentage reducing from 50.8% to 36.1%. Furthermore, <i>E. coli</i> after dual-wavelength UV-C irradiation exhibited dark decay, in which the inactivation efficiency was further enhanced during dark treatment. Therefore, these results suggest that dual-wavelength UV-C could inhibit the light reactivation and dark repair of <i>E. coli</i>, ensuring the water biosafety, as well as providing reference for the development of effective and safe water disinfection technologies.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1443-1449"},"PeriodicalIF":0.0000,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"环境科学","FirstCategoryId":"1087","ListUrlMain":"https://doi.org/10.13227/j.hjkx.202401163","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"Environmental Science","Score":null,"Total":0}
引用次数: 0
Abstract
Ultraviolet-C (UV-C) irradiation can effectively deactivate pathogenic microorganisms. The far UV-C (200-230 nm) and conventional UV-C (250-280 nm) can damage the proteins and nucleic acids of pathogenic microorganisms, respectively. The combination of far and conventional UV-C has the potential of synergistic inactivation. However, relevant studies remain limited owing to the lack of appropriate experimental setups. Therefore, this study established a mini-fluidic photoreaction system equipped with a KrCl excimer lamp and a low-pressure mercury lamp. This system could independently/simultaneously deliver stable 222 nm (far UV-C) and 254 nm (conventional UV-C) irradiations. Subsequently, the system was used to investigate the synergistic effect of dual-wavelength UV-C (the combination of 222 nm and 254 nm UV-C) on Escherichia coli (E. coli) inactivation and the subsequent impact on photo- and dark-reactivation. The results indicated that dual-wavelength UV-C had a significant synergistic effect on E. coli inactivation, with a synergistic coefficient up to 2.2. Additionally, comparing to 254 nm UV irradiation, the photo-reactivation of E. coli after dual-wavelength UV-C irradiation was weakened, with the maximum lg reactivation percentage reducing from 50.8% to 36.1%. Furthermore, E. coli after dual-wavelength UV-C irradiation exhibited dark decay, in which the inactivation efficiency was further enhanced during dark treatment. Therefore, these results suggest that dual-wavelength UV-C could inhibit the light reactivation and dark repair of E. coli, ensuring the water biosafety, as well as providing reference for the development of effective and safe water disinfection technologies.