The inactivation of the coliphage MS2 (a human virus indicator) by solar photo-Fenton at near neutral pH in carbonate buffer solution matrix was evaluated. The effects of reactant concentration (H2O2, Fe2+, Fe3+) and solar irradiance on the photo-Fenton process were studied. Specifically, the solar exposure/Fe3+ treatment showed a strong dependence on the iron concentration and solar irradiance intensity leading to complete inactivation (from 10(6) PFU mL(-1) to the detection limit) with 1 mg L-1 of Fe3+ and 60 min of solar irradiance (45 W m(-2)). The MS2 inactivation observed with the photo-Fenton process (solar exposure/H2O2/Fe2+/3+) carried out with Fe3+, was faster than with Fe2+ (detection limit achieved at 20 min and 50 min, respectively). Moreover, virus inactivation by photo-Fenton under different solar irradiance values (15,30 and 45 W m(-2)), H2O2 and Fe3+ concentrations (0.1, 0.5 and I mg L-1) and different pH values (6, 7 and 8) were evaluated. In order to validate the efficiency of the photo-Fenton process at near neutral pH on virus inactivation, the photocatalytic treatment was carried out in natural water (Lake Geneva, Switzerland) and with a human virus (Echovirus). Finally, a conceptual mechanistic interpretation was proposed regarding how solar photo-Fenton acts on viruses in water, involving the key species Fe2+, Fe3+, H2O2, solar irradiance, organic matter, and their possible reactions and interactions. (C) 2015 Elsevier B.V. All rights reserved.
César Pulgarin, Stefanos Giannakis, Jun Ma, Da Wang, Shuang Song
César Pulgarin, Stefanos Giannakis, Giulio Farinelli, Ogadimma Cassandra Oji-Okoro