title: Photocatalytic inactivation of viruses using titanium dioxide nanoparticles and low-pressure UV light.
abstract: The carcinogenic potential of chlorine disinfection by-products and recent changes in water quality regulations have led to a greater emphasis on alternative disinfection mechanisms. In this study, the efficacy of bench-scale and pilot-scale titanium dioxide (TiO(2)) photocatalytic disinfection was explored using four bacteriophages (MS2, PRD1, phi-X174, and fr). The optimized bench-scale experiments indicated that 1 mg/L of Degussa P25 TiO(2) irradiated by low-pressure ultraviolet (UV) light reduced the dose requirements for viral inactivation in comparison to UV light alone. The highest UV dose reductions for 4-log inactivation of PRD1, MS2, phi-X174, and fr were 19%, 15%, 6%, and 0%, respectively. Bench-scale photocatalysis was inhibited by limited adsorption of the viruses onto the TiO(2) nanoparticles, as indicated by the poor results for high TiO(2) concentrations. Subsequently, pilot-scale experiments were completed using the Photo-Cat Lab from Purifics. The annular reactor configuration and increased viral adsorption dramatically improved photocatalytic inactivation for samples with high TiO(2) concentrations. Using the Photo-Cat Lab, 2-log inactivation of the bacteriophages was achieved with 400 mg/L of Degussa P25 TiO(2) and a UV dose of approximately 34 mJ/cm(2) (energy consumption of 0.33 kWh/m(3))-a 700-fold decrease in energy use compared to bench-scale photocatalysis.
authors.affiliation: National Science Foundation Water Quality Center, Department of Civil and Environmental Engineering, Arizona State University, Tempe, Arizona 85287-5306, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Gerrity
authors.forename: Hodon
authors.initials: H
authors.lastname: Ryu
authors.forename: John
authors.initials: J
authors.lastname: Crittenden
authors.forename: Morteza
authors.initials: M
authors.lastname: Abbaszadegan
mesh_terms: D001435:Bacteriophages / Q000187:drug effects* / Q000528:radiation effects; D002384:Catalysis; D053768:Metal Nanoparticles; D010777:Photochemistry; D010865:Pilot Projects; D014025:Titanium / Q000494:pharmacology*; D014466:Ultraviolet Rays
chemical_list: C009495:titanium dioxide; D014025:Titanium