title: Oxidative degradation of nalidixic acid by nano-magnetite via Fe2+/O2-mediated reactions.
abstract: Organic pollution has become a critical issue worldwide due to the increasing input and persistence of organic compounds in the environment. Iron minerals are potentially able to degrade efficiently organic pollutants sorbed to their surfaces via oxidative or reductive transformation processes. Here, we explored the oxidative capacity of nano-magnetite (Fe3O4) having ∼ 12 nm particle size, to promote heterogeneous Fenton-like reactions for the removal of nalidixic acid (NAL), a recalcitrant quinolone antibacterial agent. Results show that NAL was adsorbed at the surface of magnetite and was efficiently degraded under oxic conditions. Nearly 60% of this organic contaminant was eliminated after 30 min exposure to air bubbling in solution in the presence of an excess of nano-magnetite. X-ray diffraction (XRD) and Fe K-edge X-ray absorption spectroscopy (XANES and EXAFS) showed a partial oxidation of magnetite to maghemite during the reaction, and four byproducts of NAL were identified by liquid chromatography-mass spectroscopy (UHPLC-MS/MS). We also provide evidence that hydroxyl radicals (HO(•)) were involved in the oxidative degradation of NAL, as indicated by the quenching of the degradation reaction in the presence of ethanol. This study points out the promising potentialities of mixed valence iron oxides for the treatment of soils and wastewater contaminated by organic pollutants.
authors.affiliation: †Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR 7590, CNRS - UPMC - IRD - MNHN, 4 Place Jussieu, F-75252 Paris Cedex 05, France.
authors.forename: Sandy G
authors.initials: SG
authors.lastname: Ardo
authors.affiliation: ‡INRA, UR251 PESSAC, Route de Saint-Cyr, F-78026 Versailles Cedex, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Nélieu
authors.affiliation: †Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR 7590, CNRS - UPMC - IRD - MNHN, 4 Place Jussieu, F-75252 Paris Cedex 05, France.
authors.forename: Georges
authors.initials: G
authors.lastname: Ona-Nguema
authors.affiliation: ‡INRA, UR251 PESSAC, Route de Saint-Cyr, F-78026 Versailles Cedex, France.
authors.forename: Ghislaine
authors.initials: G
authors.lastname: Delarue
authors.affiliation: †Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR 7590, CNRS - UPMC - IRD - MNHN, 4 Place Jussieu, F-75252 Paris Cedex 05, France.
authors.forename: Jessica
authors.initials: J
authors.lastname: Brest
authors.affiliation: †Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR 7590, CNRS - UPMC - IRD - MNHN, 4 Place Jussieu, F-75252 Paris Cedex 05, France.
authors.forename: Elsa
authors.initials: E
authors.lastname: Pironin
authors.affiliation: †Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR 7590, CNRS - UPMC - IRD - MNHN, 4 Place Jussieu, F-75252 Paris Cedex 05, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Morin
mesh_terms: D000327:Adsorption; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005290:Ferric Compounds / Q000737:chemistry; D052203:Ferrosoferric Oxide / Q000737:chemistry; D017665:Hydroxyl Radical; D007501:Iron / Q000737:chemistry*; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D009268:Nalidixic Acid / Q000737:chemistry*; D010084:Oxidation-Reduction; D053719:Tandem Mass Spectrometry; D056928:X-Ray Absorption Spectroscopy; D014961:X-Ray Diffraction
chemical_list: D005290:Ferric Compounds; D058185:Magnetite Nanoparticles; C000499:ferric oxide; D017665:Hydroxyl Radical; D009268:Nalidixic Acid; D007501:Iron; D052203:Ferrosoferric Oxide