title: A novel combined solar pasteurizer/TiO2continuous-flow reactor for decontamination and disinfection of drinking water.
abstract: A new combined solar plant including an annular continuous-flow compound parabolic collector (CPC) reactor and a pasteurization system was designed, built, and tested for simultaneous drinking water disinfection and chemical decontamination. The plant did not use pumps and had no electricity costs. First, water continuously flowed through the CPC reactor and then entered the pasteurizer. The temperature and water flow from the plant effluent were controlled by a thermostatic valve located at the pasteurizer outlet that opened at 80 °C. The pasteurization process was simulated by studying the effect of heat treatment on the death kinetic parameters (D and z values) of Escherichia coli K12 (CECT 4624). 99.1% bacteria photo-inactivation was reached in the TiO2-CPC system (0.60 mg cm-2TiO2), and chemical decontamination in terms of antipyrine degradation increased with increasing residence time in the TiO2-CPC system, reaching 70% degradation. The generation of hydroxyl radicals (between 100 and 400 nmol L-1) was a key factor in the CPC system efficiency. Total thermal bacteria inactivation was attained after pasteurization in all cases. Chemical degradation and bacterial photo-inactivation in the TiO2-CPC system were improved with the addition of 150 mg L-1of H2O2, which generated approximately 2000-2300 nmol L-1of HO●radicals. Finally, chemical degradation and bacterial photo-inactivation kinetic modelling in the annular CPC photoreactor were evaluated. The effect of the superficial liquid velocity on the overall rate constant was also studied. Both antipyrine degradation and E. coli photo-inactivation were found to be controlled by the catalyst surface reaction rate.
authors.affiliation: Department of Chemical Engineering, Grupo IMAES, Escuela Técnica Superior de Ingenieros Industriales, Instituto de Investigaciones Energéticas y Aplicaciones Industriales (INEI), University of Castilla-La Mancha, Avda. Camilo José Cela 3, 13071 Ciudad Real, Spain. Electronic address: josemaria.monteagudo@uclm.es.
authors.forename: José María
authors.initials: JM
authors.lastname: Monteagudo
authors.affiliation: Department of Chemical Engineering, Grupo IMAES, Escuela Técnica Superior de Ingenieros Industriales, Instituto de Investigaciones Energéticas y Aplicaciones Industriales (INEI), University of Castilla-La Mancha, Avda. Camilo José Cela 3, 13071 Ciudad Real, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Durán
authors.affiliation: Department of Chemical Engineering, Grupo IMAES, Escuela Técnica Superior de Ingenieros Industriales, Instituto de Investigaciones Energéticas y Aplicaciones Industriales (INEI), University of Castilla-La Mancha, Avda. Camilo José Cela 3, 13071 Ciudad Real, Spain.
authors.forename: Israel San
authors.initials: IS
authors.lastname: Martín
authors.affiliation: Department of Chemical Engineering, Grupo IMAES, Escuela Técnica Superior de Ingenieros Industriales, Instituto de Investigaciones Energéticas y Aplicaciones Industriales (INEI), University of Castilla-La Mancha, Avda. Camilo José Cela 3, 13071 Ciudad Real, Spain.
authors.forename: Alba María
authors.initials: AM
authors.lastname: Acevedo
mesh_terms: D002384:Catalysis; D003666:Decontamination; D004203:Disinfection / Q000379:methods; D060766:Drinking Water / Q000737:chemistry*; D004926:Escherichia coli / Q000187:drug effects; D055668:Photochemical Processes; D013472:Sunlight; D014025:Titanium / Q000737:chemistry; D018508:Water Purification / Q000379:methods*
chemical_list: D060766:Drinking Water; C009495:titanium dioxide; D014025:Titanium
keywords: Escherichia coli K12; Modelling; Pasteurization; Photocatalysis; Solar disinfection