title: Characterization of intermediate products of solar photocatalytic degradation of ranitidine at pilot-scale.
abstract: In the present study the mechanisms of solar photodegradation of H(2)-receptor antagonist ranitidine (RNTD) were studied in a well-defined system of a pilot plant scale Compound Parabolic Collector (CPC) reactor. Two types of heterogeneous photocatalytic experiments were performed: catalysed by titanium-dioxide (TiO(2)) semiconductor and by Fenton reagent (Fe(2+)/H(2)O(2)), each one with distilled water and synthetic wastewater effluent matrix. Complete disappearance of the parent compounds and discreet mineralization were attained in all experiments. Furthermore, kinetic parameters, main intermediate products, release of heteroatoms and formation of carboxylic acids are discussed. The main intermediate products of photocatalytic degradation of RNTD have been structurally elucidated by tandem mass spectrometry (MS(2)) experiments performed at quadrupole-time of flight (QqToF) mass analyzer coupled to ultra-performance liquid chromatograph (UPLC). RNTD displayed high reactivity towards OH radicals, although a product of conduction band electrons reduction was also present in the experiment with TiO(2). In the absence of standards, quantification of intermediates was not possible and only qualitative profiles of their evolution could be determined. The proposed TiO(2) and photo-Fenton degradation routes of RNTD are reported for the first time.
authors.affiliation: Department of Environmental Chemistry, IDAEA-CSIC, c/Jordi Girona 18-26, 08034 Barcelona, Spain.
authors.forename: Jelena
authors.initials: J
authors.lastname: Radjenović
authors.forename: Carla
authors.initials: C
authors.lastname: Sirtori
authors.forename: Mira
authors.initials: M
authors.lastname: Petrović
authors.forename: Damià
authors.initials: D
authors.lastname: Barceló
authors.forename: Sixto
authors.initials: S
authors.lastname: Malato
mesh_terms: D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D006861:Hydrogen Peroxide / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D007700:Kinetics; D010782:Photolysis; D010865:Pilot Projects; D011899:Ranitidine / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013472:Sunlight; D014025:Titanium / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: C045076:Fenton's reagent; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D011899:Ranitidine; D006861:Hydrogen Peroxide; D014025:Titanium; D007501:Iron