title: Uranium(VI) Scavenging by Amorphous Iron Phosphate Encrusting Sphaerotilus natans Filaments.
abstract: U(VI) sorption to iron oxyhydroxides, precipitation of phosphate minerals, as well as biosorption on bacterial biomass are among the most reported processes able to scavenge U(VI) under oxidizing conditions. Although phosphates significantly influence bacterially mediated as well as iron oxyhydroxide mediated scavenging of uranium, the sorption or coprecipitation of U(VI) with poorly crystalline nanosized iron phosphates has been scarcely documented, especially in the presence of microorganisms. Here we show that dissolved U(VI) can be bound to amorphous iron phosphate during their deposition on Sphaerotilus natans filamentous bacteria. Uranium LIII-edge EXAFS analysis reveals that the adsorbed uranyl ions share an equatorial oxygen atom with a phosphate tetrahedron of the amorphous iron phosphate, with a characteristic U-P distance of 3.6 Å. In addition, the uranyl ions are connected to FeO6 octahedra with U-Fe distances at ~3.4 Å and at ~4.0 Å. The shortest U-Fe distance corresponds to a bidentate edge-sharing complex often reported for uranyl adsorption onto iron oxyhydroxides, whereas the longest U-Fe and U-P distances can be interpreted as a bidentate corner-sharing complex, in which two adjacent equatorial oxygen atoms are shared with the vertices of a FeO6 octahedron and of a phosphate tetrahedron. Furthermore, based on these sorption reactions, we demonstrate the ability of an attached S. natans biofilm to remove uranium from solution without any filtration step.
authors.affiliation: Université Paris-Est, Laboratoire Géomatériaux et Environnement (EA 4508), UPEM, 77454 Marne-la-Vallée, France.|University of Cassino and Southern Lazio , Department of Civil and Mechanical Engineering, 03043, Cassino (FR), Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Seder-Colomina
authors.affiliation: Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie (IMPMC), UMR 7590, CNRS, UPMC, MNHN, IRD, 4 place Jussieu, 75252 Paris Cedex 05, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Morin
authors.affiliation: Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie (IMPMC), UMR 7590, CNRS, UPMC, MNHN, IRD, 4 place Jussieu, 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, MNHN, IRD, 4 place Jussieu, 75252 Paris Cedex 05, France.
authors.forename: Georges
authors.initials: G
authors.lastname: Ona-Nguema
authors.affiliation: Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie (IMPMC), UMR 7590, CNRS, UPMC, MNHN, IRD, 4 place Jussieu, 75252 Paris Cedex 05, France.
authors.forename: Nilka
authors.initials: N
authors.lastname: Gordien
authors.affiliation: Institut National de Recherche en Sciences et Technologies pour l'Environnement et l'Agriculture (Irstea) UR HBAN, CS 10030-92761 Antony Cedex, France.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Pernelle
authors.affiliation: Dutch-Belgian Beamline (DUBBLE), ESRF-The European Synchrotron, CS40220, 38043 Grenoble Cedex 9, France.
authors.forename: Dipanjan
authors.initials: D
authors.lastname: Banerjee
authors.affiliation: Dutch-Belgian Beamline (DUBBLE), ESRF-The European Synchrotron, CS40220, 38043 Grenoble Cedex 9, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Mathon
authors.affiliation: University of Cassino and Southern Lazio , Department of Civil and Mechanical Engineering, 03043, Cassino (FR), Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Esposito
authors.affiliation: Université Paris-Est, Laboratoire Géomatériaux et Environnement (EA 4508), UPEM, 77454 Marne-la-Vallée, France.
authors.forename: Eric D
authors.initials: ED
authors.lastname: van Hullebusch
mesh_terms: D000327:Adsorption; D018441:Biofilms; D011232:Chemical Precipitation; D005290:Ferric Compounds / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D016018:Least-Squares Analysis; D008855:Microscopy, Electron, Scanning; D008903:Minerals / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry; D013052:Spectrometry, X-Ray Emission; D042744:Sphaerotilus / Q000737:chemistry*; D014501:Uranium / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D005290:Ferric Compounds; D008903:Minerals; D010710:Phosphates; C021024:ferric hydroxide; D014501:Uranium; D007501:Iron; C035885:ferric phosphate