title: Bacteria and fungi inactivation by photocatalysis under UVA irradiation: liquid and gas phase.
abstract: In the last decade, environmental risks associated with wastewater treatment plants (WWTPs) have become a concern in the scientific community due to the absence of specific legislation governing the occupational exposure limits (OEL) for microorganisms present in indoor air. Thus, it is necessary to develop techniques to effectively inactivate microorganisms present in the air of WWTPs facilities. In the present work, ultraviolet light A radiation was used as inactivation tool. The microbial population was not visibly reduced in the bioaerosol by ultraviolet light A (UVA) photolysis. The UVA photocatalytic process for the inactivation of microorganisms (bacteria and fungi, ATCC strains and isolates from indoor air samples of a WWTP) using titanium dioxide (TiO2P25) and zinc oxide (ZnO) was tested in both liquid-phase and airborne conditions. In the slurry conditions at liquid phase, P25 showed a better performance in inactivation. For this reason, gas-phase assays were performed in a tubular photoreactor packed with cellulose acetate monolithic structures coated with P25. The survival rate of microorganisms under study decreased with the catalyst load and the UVA exposure time. Inactivation of fungi was slower than resistant bacteria, followed by Gram-positive bacteria and Gram-negative bacteria. Graphical abstract Inactivation of fungi and bacteria in gas phase by photocatalitic process performed in a tubular photoreactor packed with cellulose acetate monolith structures coated with TiO2.
authors.affiliation: Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal. caio.rodrigues@iqm.unicamp.br.|Institute of Chemistry, Department of Analytical Chemistry, University of Campinas, P.O. Box 6154, Campinas, SP, 13083-970, Brazil. caio.rodrigues@iqm.unicamp.br.
authors.forename: Caio
authors.initials: C
authors.lastname: Rodrigues-Silva
authors.affiliation: Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal.
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Miranda
authors.affiliation: Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal.
authors.forename: Filipe V S
authors.initials: FVS
authors.lastname: Lopes
authors.affiliation: Microbiology Service, Biological Sciences Department, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira, N° 228, 4050-313, Porto, Portugal.
authors.forename: Mário
authors.initials: M
authors.lastname: Silva
authors.affiliation: Chemical Engineering Program - COPPE, Federal University of Rio de Janeiro, P.O. Box 68 502, Rio de Janeiro, RJ, 21941-972, Brazil.
authors.forename: Márcia
authors.initials: M
authors.lastname: Dezotti
authors.affiliation: Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal.
authors.forename: Adrián M T
authors.initials: AMT
authors.lastname: Silva
authors.affiliation: Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal.
authors.forename: Joaquim L
authors.initials: JL
authors.lastname: Faria
authors.affiliation: Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal.
authors.forename: Rui A R
authors.initials: RAR
authors.lastname: Boaventura
authors.affiliation: Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal. vilar@fe.up.pt.
authors.forename: Vítor J P
authors.initials: VJP
authors.lastname: Vilar
authors.affiliation: Microbiology Service, Biological Sciences Department, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira, N° 228, 4050-313, Porto, Portugal.|Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Rua dos Bragas 289, P, 4050-123, Porto, Portugal.
authors.forename: Eugénia
authors.initials: E
authors.lastname: Pinto
mesh_terms: D000391:Air Microbiology; D001419:Bacteria / Q000302:isolation & purification; D002384:Catalysis; D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D005658:Fungi / Q000302:isolation & purification; D050296:Microbial Viability / Q000528:radiation effects; D010782:Photolysis; D014025:Titanium / Q000737:chemistry; D014466:Ultraviolet Rays; D062065:Wastewater / Q000382:microbiology; D018508:Water Purification; D015034:Zinc Oxide / Q000737:chemistry
chemical_list: D002482:Cellulose; D014025:Titanium; D062065:Wastewater; D015034:Zinc Oxide; C009495:titanium dioxide; C005062:acetylcellulose
keywords: Air disinfection; Monolithic structures; Photocatalysis; Water disinfection