Photo-Fenton and TiO<sub>2</sub> Photocatalytic Inactivation of Model Microorganisms under UV-A; Comparative Efficacy and Optimization
Eirini Kanata,
Ioannis Paspaltsis,
Sotiris Sotiriadis,
Chrysanthi Berberidou,
Sophia Tsoumachidou,
Dimitra Dafou,
Konstantinos Xanthopoulos,
Minas Arsenakis,
Athanasios Arsenakis,
Ioannis Poulios,
Theodoros Sklaviadis
Affiliations
Eirini Kanata
Laboratory of Pharmacology, Department of Pharmacy, School of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Ioannis Paspaltsis
Laboratory of Pharmacology, Department of Pharmacy, School of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Sotiris Sotiriadis
Department of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Chrysanthi Berberidou
Laboratory of Physical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Sophia Tsoumachidou
Laboratory of Physical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Dimitra Dafou
Department of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Konstantinos Xanthopoulos
Laboratory of Pharmacology, Department of Pharmacy, School of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Minas Arsenakis
Laboratory of General Microbiology, Department of Genetics Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Athanasios Arsenakis
STERIMED SA, G’ Fassi, Building Block 52b, Sindos Industrial Area, 57022 Thessaloniki, Greece
Ioannis Poulios
Laboratory of Physical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Theodoros Sklaviadis
Laboratory of Pharmacology, Department of Pharmacy, School of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Photocatalytic inactivation of pathogens in aqueous waste is gaining increasing attention. Several homogeneous and heterogeneous photocatalytic protocols exist using the Fenton’s reagent and TiO2, respectively. A comprehensive study of homogeneous and heterogeneous photocatalysis on a range of microorganisms will significantly establish the most efficient method. Here, we report a comparative study of TiO2- and Fe+3-based photocatalytic inactivation under UV-A of diverse microorganisms, including Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, bacterial spores (Bacillus stearothermophilus spores) and viruses (MS2). We also present data on the optimization of TiO2 photocatalysis, including optimal catalyst concentration and H2O2 supplementation. Our results indicate that both photo-Fenton and TiO2 could be successfully applied for the management of microbial loads in liquids. Efficient microorganism inactivation is achieved with homogeneous photocatalysis (7 mg/L Fe+3, 100 mg/L H2O2, UV-A) in a shorter processing time compared to heterogeneous photocatalysis (0.5 g/L TiO2, UV-A), whereas similar or shorter processing is required when heterogenous photocatalysis is performed using microorganism-specific optimized TiO2 concentrations and H2O2 supplementation (100 mg/L); higher H2O2 concentrations further enhance the heterogenous photocatalytic inactivation efficiency. Our study provides a template protocol for the design and further application for large-scale photocatalytic approaches to inactivate pathogens in liquid biomedical waste.
