title: Degradation of the pharmaceutical metronidazole via UV, Fenton and photo-Fenton processes.
abstract: Degradation rates and removal efficiencies of Metronidazole using UV, UV/H2O2, H2O2/Fe2+, and UV/H2O2/Fe2+ were studied in de-ionized water. The four different oxidation processes were compared for the removal kinetics of the antimicrobial pharmaceutical Metronidazole. It was found that the degradation of Metronidazole by UV and UV/H2O2 exhibited pseudo-first order reaction kinetics. By applying H2O2/Fe2+, and UV/H2O2/Fe2+ the degradation kinetics followed a second order behavior. The quantum yields for direct photolysis, measured at 254 nm and 200-400 nm, were 0.0033 and 0.0080 mol E(-1), respectively. Increasing the concentrations of hydrogen peroxide promoted the oxidation rate by UV/ H2O2. Adding more ferrous ions enhanced the oxidation rate for the H2O2/Fe2+ and UV/H2O2/Fe2+ processes. The major advantages and disadvantages of each process and the complexity of comparing the various advanced oxidation processes on an equal basis are discussed.
authors.affiliation: Department of Civil and Environmental Engineering, Duke University, Box 90287, Durham, NC 27708-0287, USA. shilla@duke.edu
authors.forename: Hilla
authors.initials: H
authors.lastname: Shemer
authors.forename: Yasemin Kaçar
authors.initials: YK
authors.lastname: Kunukcu
authors.forename: Karl G
authors.initials: KG
authors.lastname: Linden
mesh_terms: D000981:Antiprotozoal Agents / Q000737:chemistry / Q000528:radiation effects; D005296:Ferrous Compounds / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D008795:Metronidazole / Q000737:chemistry* / Q000528:radiation effects*; D010782:Photolysis; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000528:radiation effects; D018508:Water Purification / Q000379:methods
chemical_list: D000981:Antiprotozoal Agents; D005296:Ferrous Compounds; D014874:Water Pollutants, Chemical; D008795:Metronidazole; C020748:ferrous sulfate; D006861:Hydrogen Peroxide