title: Disinfection and Mechanistic Insights of Escherichia coli in Water by Bismuth Oxyhalide Photocatalysis.
abstract: This study demonstrates the potential of a new BiOCl0.875Br0.125photocatalyst to disinfect Escherichia coli in water under simulated solar irradiation. Photocatalytic efficiency was examined for different photocatalyst loadings, solar wavelengths, exposure times, photocatalyst concentration × contact time (Ct) concept and with the use of scavengers. To elucidate the inactivation mechanism, we examined DNA damage, membrane damage, lipid peroxidation and protein release. Both photolysis and photocatalysis were negligible under visible irradiation, but enhanced photocatalytic activity was observed under solar UVA (λ > 320 nm) and UVB (λ > 280 nm), with 1.5 and 3.6 log inactivation, respectively, after 40 min of irradiation. The log inactivation vs Ct curve for E. coli by UVA/BiOCl0.875Br0.125was fairly linear, with Ct = 10 g L-1× min, resulting in 2 log inactivation. Photocatalytic treatment led to membrane damage, but without lipid peroxidation. Accordingly, protein was released from the cells after UVA or UVA/BiOCl0.875Br0.125treatment. Photocatalysis also increased endonuclease-sensitive sites vs photolysis alone, by an unknown mechanism. Finally, E. coli inactivation was not influenced by the addition of tert-butanol or l-histidine, implying that neither hydroxyl radicals nor singlet oxygen reactive species are involved in the inactivation process.
authors.affiliation: School of Mechanical Engineering, Tel Aviv University, Tel Aviv, Israel.|The Water Research Center at Tel-Aviv University, Tel Aviv, Israel.
authors.forename: Ilana
authors.initials: I
authors.lastname: Sherman
authors.affiliation: Department of Biology and Environment, Faculty of Natural Sciences, University of Haifa, Oranim, Tivon, Israel.
authors.forename: Yoram
authors.initials: Y
authors.lastname: Gerchman
authors.affiliation: Casali center of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel.
authors.forename: Yoel
authors.initials: Y
authors.lastname: Sasson
authors.affiliation: Casali center of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel.
authors.forename: Hani
authors.initials: H
authors.lastname: Gnayem
authors.affiliation: School of Mechanical Engineering, Tel Aviv University, Tel Aviv, Israel.|The Water Research Center at Tel-Aviv University, Tel Aviv, Israel.
authors.forename: Hadas
authors.initials: H
authors.lastname: Mamane
mesh_terms: D001729:Bismuth / Q000737:chemistry*; D004926:Escherichia coli / Q000528:radiation effects*; D050296:Microbial Viability / Q000187:drug effects / Q000528:radiation effects; D055668:Photochemical Processes; D013472:Sunlight; D014466:Ultraviolet Rays; D014867:Water / Q000737:chemistry; D014871:Water Microbiology
chemical_list: D014867:Water; C044685:bismuth oxychloride; D001729:Bismuth