title: Water disinfection using photo-Fenton: Effect of temperature on Enterococcus faecalis survival.
abstract: The photo-Fenton process is a promising alternative to classical water disinfection treatments, although information in this regard is scarce due to its operational limitations. The effect of temperature (10, 20, 30 and 40 °C) was studied on water disinfection using the photo-Fenton reaction at initial near neutral pH with resorcinol as a model of natural organic matter (NOM). Enterococcus faecalis, a Gram-positive microorganism, was selected as an indicator of wastewater faecal contamination. The individual effects of different variables involved in this process (mechanical stress, UVA, H(2)O(2), Fe(2+), H(2)O(2)/Fe(2+), UVA/Fe(2+), UVA/H(2)O(2) and UVA/H(2)O(2)/Fe(2+)) were determined. UVA and H(2)O(2) led to a 2.5-log decrease individually and the combined effect of both variables managed to disinfect up to the detection limit (i.e. from a 5.5 to a 6-log reduction) over the same treatment time. Only by adding 10 mg L(-1) of Fe(2+), the inactivation time was reduced from 120 min (H(2)O(2)/UVA) to 80 min (H(2)O(2)/UVA/Fe(2+); photo-Fenton) with 120 mg L(-1) of H(2)O(2). A higher disinfection result for E. faecalis was observed by increasing temperature according to the Arrhenius equation in the photo-Fenton process. The detection limit was not reached at 10 °C and, to achieve the detection limit at 20, 30 and 40 °C, 80, 65 and 40 min were needed, respectively. The decrease in treatment time is a key factor in applying the photo-Fenton disinfection process to a wastewater treatment plant.
authors.affiliation: Department of Chemical Engineering, University of Almería, La Cañada de San Urbano, 04120 Almería, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Ortega-Gómez
authors.forename: P
authors.initials: P
authors.lastname: Fernández-Ibáñez
authors.forename: M M
authors.initials: MM
authors.lastname: Ballesteros Martín
authors.forename: M I
authors.initials: MI
authors.lastname: Polo-López
authors.forename: B
authors.initials: B
authors.lastname: Esteban García
authors.forename: J A
authors.initials: JA
authors.lastname: Sánchez Pérez
mesh_terms: D004203:Disinfection / Q000379:methods*; D013293:Enterococcus faecalis / Q000254:growth & development*; D006863:Hydrogen-Ion Concentration; D010777:Photochemistry; D013696:Temperature; D018508:Water Purification / Q000379:methods*