title: Solar photocatalytic disinfection of E. coli and bacteriophages MS2, ΦX174 and PR772 using TiO2, ZnO and ruthenium based complexes in a continuous flow system.
abstract: The performance of photocatalytic treatment processes were assessed using different photocatalysts against E. coli and bacteriophages MS2, ΦX174 and PR772, in a recirculating continuous flow compound parabolic collector system under real sunlight conditions. Suspended TiO2and ZnO nanoparticle powders and Tris(2,2'-bipyridyl)dichlororuthenium(II) hexahydrate in solution were tested separately, as well as in combination, using E. coli. For a 3-log reduction of E. coli in distilled water, inactivation rates in terms of cumulative dose were in the order Ru(bpy)3Cl2>(TiO2& Ru(bpy)3Cl2)>(ZnO & Ru(bpy)3Cl2)>ZnO>TiO2>photolysis. Reactivation of E. coli was observed following all trials despite the detection limit being reached, although the reactivated colonies were observed to be under stress and much slower growing when compared to original colonies. Treatment with Ru(bpy)3Cl2was also compared against standard photolysis of bacteriophages MS2, ΦX174 and PR772 with the order of photolytic inactivation for a 3-log reduction in terms of cumulative UV-A dose being ΦX174>PR772>MS2. However, MS2 was found to be the most susceptible bacteriophage to treatment with Ru(bpy)3Cl2, with complete removal of the phage observed within the first 15min of exposure. Ru(bpy)3Cl2also significantly improved inactivation rates for PR772 and ΦX174.
authors.affiliation: Department of Civil, Structural and Environmental Engineering, Museum Building, Trinity College Dublin, College Green, Dublin 2, Ireland. Electronic address: macmahoj@tcd.ie.
authors.forename: Joanne
authors.initials: J
authors.lastname: Mac Mahon
authors.affiliation: Centre for Precision Engineering, Materials and Manufacturing Research (PEM), Institute of Technology, Sligo, Ireland; Nanotechnology and Bio-Engineering Research Group, Department of Environmental Science, Institute of Technology Sligo, Ireland.
authors.forename: Suresh C
authors.initials: SC
authors.lastname: Pillai
authors.affiliation: School of Chemistry, Trinity College Dublin, College Green, Dublin 2, Ireland. Electronic address: laurence.gill@tcd.ie.
authors.forename: John M
authors.initials: JM
authors.lastname: Kelly
authors.affiliation: Department of Civil, Structural and Environmental Engineering, Museum Building, Trinity College Dublin, College Green, Dublin 2, Ireland.
authors.forename: Laurence W
authors.initials: LW
authors.lastname: Gill
mesh_terms: D010584:Bacteriophage phi X 174 / Q000187:drug effects / Q000528:radiation effects; D001435:Bacteriophages / Q000187:drug effects* / Q000528:radiation effects; D002384:Catalysis; D004202:Disinfectants / Q000737:chemistry / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects* / Q000528:radiation effects; D017909:Levivirus / Q000187:drug effects / Q000528:radiation effects; D009942:Organometallic Compounds / Q000737:chemistry / Q000494:pharmacology; D010782:Photolysis / Q000187:drug effects* / Q000528:radiation effects; D014025:Titanium / Q000737:chemistry / Q000494:pharmacology; D014466:Ultraviolet Rays; D038301:Virus Inactivation / Q000187:drug effects / Q000528:radiation effects; D018508:Water Purification; D015034:Zinc Oxide / Q000737:chemistry / Q000494:pharmacology
chemical_list: D004202:Disinfectants; D009942:Organometallic Compounds; C415768:tris(2,2'-bipyridyl)ruthenium(II); C009495:titanium dioxide; D014025:Titanium; D015034:Zinc Oxide
keywords: Bacteriophages (MS2, ΦX174 and PR772); E. coli; Ruthenium; Solar photocatalytic; TiO(2); ZnO