title: Oxidative degradation of sulfathiazole by Fenton and photo-Fenton reactions.
abstract: This article presents experimental results on 47 μmol L(-1) sulfathiazole (STZ) degradation by Fenton and photo-Fenton reactions using multivariate analysis. The optimal experimental conditions for reactions were obtained by Response Surface Methodology (RSM). In the case of the Fenton reactions there were 192 μmol L(-1) ferrous ions (Fe(II)) and 1856 μmol L(-1) hydrogen peroxide (H2O2), as compared with 157 μmol L(-1) (Fe(II)) and 1219 μmol L(-1) (H2O2) for photo-Fenton reactions. Under these conditions, around 90% of STZ degradation were achieved after 8 minutes treatment by Fenton and photo-Fenton reactions, respectively. Moreover, a marked difference was observed in the total organic carbon (TOC) removal after 60-min treatment, achieving 30% and 75% for the Fenton and photo-Fenton reactions, respectively. Acetic, maleic, succinic and oxamic acids could be identified as main Fenton oxidation intermediates. A similar pattern was found in the case of photo-Fenton reaction, including the presence of oxalic acid and ammonia at short periods of irradiation with UV-A. The calculated values of Average Oxidation State (AOS) corroborate the formation of oxidized products from the initial steps of the reaction.
authors: a Facultad de Ciencias Químicas , Universidad de Concepción , Casilla , Concepción , Chile.
authors: Marizú
authors: M
authors: Velásquez
authors: I Paola
authors: IP
authors: Santander
authors: David R
authors: DR
authors: Contreras
authors: Jorge
authors: J
authors: Yáñez
authors: Claudio
authors: C
authors: Zaror
authors: Ricardo A
authors: RA
authors: Salazar
authors: Montserrat
authors: M
authors: Pérez-Moya
authors: Héctor D
authors: HD
authors: Mansilla
mesh_terms: D000641:Ammonia / Q000032:analysis; D002244:Carbon / Q000032:analysis; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D015999:Multivariate Analysis; D019815:Oxalic Acid / Q000032:analysis; D010084:Oxidation-Reduction; D010777:Photochemistry / Q000379:methods; D000077589:Sulfathiazole; D013432:Sulfathiazoles / Q000737:chemistry*
chemical_list: C045076:Fenton's reagent; D013432:Sulfathiazoles; D002244:Carbon; D000641:Ammonia; D019815:Oxalic Acid; D006861:Hydrogen Peroxide; D007501:Iron; D000077589:Sulfathiazole