title: Inactivation of natural enteric bacteria in real municipal wastewater by solar photo-Fenton at neutral pH.
abstract: This study analyses the use of the solar photo-Fenton treatment in compound parabolic collector photo-reactors at neutral pH for the inactivation of wild enteric Escherichia coli and total coliform present in secondary effluents of a municipal wastewater treatment plant (SEWWTP). Control experiments were carried out to find out the individual effects of mechanical stress, pH, reactants concentration, and UVA radiation as well as the combined effects of UVA-Fe and UVA-H2O2. The synergistic germicidal effect of solar-UVA with 50 mg L(-1) of H2O2 led to complete disinfection (up to the detection limit) of total coliforms within 120 min. The disinfection process was accelerated by photo-Fenton, achieving total inactivation in 60 min reducing natural bicarbonate concentration found in the SEWWTP from 250 to 100 mg L(-1) did not give rise to a significant enhancement in bacterial inactivation. Additionally, the effect of hydrogen peroxide and iron dosage was evaluated. The best conditions were 50 mg L(-1) of H2O2 and 20 mg L(-1) of Fe(2+). Due to the variability of the SEWWTP during autumn and winter seasons, the inactivation kinetic constant varied between 0.07 ± 0.04 and 0.17 ± 0.04 min(-1). Moreover, the water treated by solar photo-Fenton fulfilled the microbiological quality requirement for wastewater reuse in irrigation as per the WHO guidelines and in particular for Spanish legislation.
authors: Department of Chemical Engineering, University of Almería, 04120 Almería, Spain; CIESOL, Joint Centre of the University of Almería-CIEMAT, 04120 Almería, Spain.
authors: E
authors: E
authors: Ortega-Gómez
authors: Department of Chemical Engineering, University of Almería, 04120 Almería, Spain; CIESOL, Joint Centre of the University of Almería-CIEMAT, 04120 Almería, Spain.
authors: B
authors: B
authors: Esteban García
authors: CIESOL, Joint Centre of the University of Almería-CIEMAT, 04120 Almería, Spain; Department of Molecular Biology and Biochemical Engineering, University of Pablo de Olavide, 41013 Sevilla, Spain.
authors: M M
authors: MM
authors: Ballesteros Martín
authors: CIESOL, Joint Centre of the University of Almería-CIEMAT, 04120 Almería, Spain; Plataforma Solar de Almería, CIEMAT, 04200 Tabernas, Almería, Spain.
authors: P
authors: P
authors: Fernández Ibáñez
authors: Department of Chemical Engineering, University of Almería, 04120 Almería, Spain; CIESOL, Joint Centre of the University of Almería-CIEMAT, 04120 Almería, Spain. Electronic address: jsanchez@ual.es.
authors: J A
authors: JA
authors: Sánchez Pérez
mesh_terms: D001639:Bicarbonates / Q000032:analysis; D004202:Disinfectants / Q000737:chemistry*; D004203:Disinfection / Q000379:methods*; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000528:radiation effects*; D004926:Escherichia coli / Q000187:drug effects / Q000528:radiation effects; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D010782:Photolysis; D012621:Seasons; D013030:Spain; D013472:Sunlight; D062065:Wastewater / Q000032:analysis*
chemical_list: D001639:Bicarbonates; D004202:Disinfectants; D006861:Hydrogen Peroxide; D007501:Iron; D062065:Wastewater; C045076:Fenton's reagent
keywords: Escherichia coli; Neutral pH; Photo-Fenton; Reclaimed water; Solar disinfection; Total coliform