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2. Redox Fluctuations and Organic Complexation Govern Uranium Redistribution from U(IV)-Phosphate Minerals in a Mining-Polluted Wetland Soil, Brittany, France

Author

John R. Bargar, Jessica Brest, Olivier Proux, Lucie Stetten, Guillaume Morin, Arnaud Mangeret, Pascale Blanchart, Anthony Julien, Pierre Lefebvre, Charlotte Cazala, Samuel M. Webb, Pauline Merrot, Pierre Le Pape, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Environnement, Géo-ingénierie et Développement (EGID), Departamento de Ingeniería Electrónica and ISOM (ETSI Telecomunicacion), Universidad Politécnica de Madrid (UPM)-Ciudad Universitaria, Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Stanford Linear Accelerator Center (SLAC), Stanford University [Stanford], Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), SLAC National Accelerator Laboratory (SLAC), and Stanford University

Subjects
Water table, chemistry.chemical_element, Wetland, 010501 environmental sciences, 010502 geochemistry & geophysics, 01 natural sciences, Redox, Phosphates, Soil, Environmental Chemistry, Organic matter, Redistribution (chemistry), ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, chemistry.chemical_classification, Minerals, geography, geography.geographical_feature_category, General Chemistry, Particulates, Uranium, chemistry, Wetlands, Environmental chemistry, [SDE]Environmental Sciences, Phosphate minerals, France, Oxidation-Reduction
Abstract

Wetlands have been proposed to naturally attenuate U transfers in the environment via U complexation by organic matter and potential U reduction. However, U mobility may depend on the identity of particulate/dissolved uranium source materials and their redox sensitivity. Here, we examined the fate of uranium in a highly contaminated wetland (up to 4500 mg·kg–1 U) impacted by former mine water discharges. Bulk U LIII-EXAFS and (micro-)XANES combined with SEM-EDXS analyses of undisturbed soil cores show a sharp U redox boundary at the water table, together with a major U redistribution from U(IV)-minerals to U(VI)-organic matter complexes. Above the water table, U is fully oxidized into mono- and bidentate U(VI)-carboxyl and monodentate U(VI)-phosphoryl complexes. Minute amounts of U(VI)-phosphate minerals are also observed. Below the water table, U is fully reduced and is partitioned between U(IV)-phosphate minerals (i.e., ningyoite and a lermontovite-like phase), and bidentate U(IV)-phosphoryl and monoden...

Published
2018
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3. Impact of a Model Soil Microorganism and of Its Secretome on the Fate of Silver Nanoparticles

Author

Elise Eymard-Vernain, Hiram Castillo-Michel, Cécile Lelong, Benoit Gallet, Romain Soulas, Vanessa Tardillo Suárez, Sarah Bureau, Olivier Proux, Géraldine Sarret, Ana Elena Pradas del Real, Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), ID21, European Synchrotron Radiation Facility, European Synchrotron Radiation Facility (ESRF), Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux (LITEN), Institut National de L'Energie Solaire (INES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), ID16b, ESRF—The European Synchrotron facility, Institut de biologie structurale (IBS - UMR 5075), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Science et Ingenierie, MAtériaux Procédés (SIMP), Université Joseph Fourier - Grenoble 1 (UJF)-École Nationale Supérieure de Physique de Grenoble (ENSPG)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géophysique Interne et Tectonophysique (LGIT), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Laboratoire Central des Ponts et Chaussées (LCPC)-Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), ID21, Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut de biologie structurale (IBS - UMR 5075 ), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Observatoire des Sciences de l'Univers de Grenoble (OSUG ), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
Silver, Microorganism, Sulfidation, Metal Nanoparticles, Nanoparticle, 02 engineering and technology, Bacillus subtilis, 010501 environmental sciences, 01 natural sciences, Silver nanoparticle, Soil, Environmental Chemistry, 0105 earth and related environmental sciences, [SDV.EE]Life Sciences [q-bio]/Ecology, environment, biology, Chemistry, Sorption, General Chemistry, 021001 nanoscience & nanotechnology, biology.organism_classification, Rate-determining step, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Chemical engineering, [SDE]Environmental Sciences, [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology, 0210 nano-technology, Oxidation-Reduction, Bacteria
Abstract

International audience; Sulfidation is a key process for silver nano-particles released from consumer products in the environment. This study focuses on the impact of a model soil microorganism , Bacillus subtilis, on the fate of pristine and already sulfidized Ag-NPs. The nanoparticles were incubated with the initial growth medium, isolated secretome, and living bacteria, and characterized for their size and morphology, agglomeration state, structure, and Ag speciation. No Ag internalization or sorption on the cell wall was detected. A partial sulfidation, leading to an Ag−Ag 2 S core−shell structure, was observed in the presence of the secretome, and the rate limiting step of the reaction was the oxidation of Ag 0 , and it was favored near the crystal dislocations. The sulfidation was complete in the presence of the living bacteria and followed an indirect pathway. Both crystalline Ag 2 S and amorphous Ag 2 S and/or Ag-thiol were identified. At the opposite, the bacteria had no impact on Ag 2 S. These results suggest that microorganisms participate in the sulfidation of Ag-NPs in aerobic systems such as unsaturated soils, and thus affect the bioavailability of Ag. It is important to take these transformations into account during exposure experiments, since they drastically change the exposure conditions. Finally, the secretome of B. subtilis might be used for the green synthesis of Ag−Ag 2 S core−shell nanoparticles.

Published
2017
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4. Redox Fluctuations and Organic Complexation Govern Uranium Redistribution from U(IV)-Phosphate Minerals in a Mining-Polluted Wetland Soil, Brittany, France

Author

Stetten, Lucie, primary, Blanchart, Pascale, additional, Mangeret, Arnaud, additional, Lefebvre, Pierre, additional, Le Pape, Pierre, additional, Brest, Jessica, additional, Merrot, Pauline, additional, Julien, Anthony, additional, Proux, Olivier, additional, Webb, Samuel M., additional, Bargar, John R., additional, Cazala, Charlotte, additional, and Morin, Guillaume, additional

Published
2018
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5. Is There a Trojan-Horse Effect during Magnetic Nanoparticles and Metalloid Cocontamination of Human Dermal Fibroblasts?

Author

Laila Benameur, Jérôme Rose, Olivier Proux, Jean-Yves Bottero, Mélanie Auffan, Corinne Chanéac, Wei Liu, Alain Botta, Armand Masion, Fabio Ziarelli, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), équipe FAME, Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut de Chimie Radicalaire (ICR), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie de la Matière Condensée de Paris (site Paris VI) (LCMCP (site Paris VI)), Université Pierre et Marie Curie - Paris 6 (UPMC)-Collège de France (CdF)-Ecole Nationale Supérieure de Chimie de Paris- Chimie ParisTech-PSL (ENSCP)-Centre National de la Recherche Scientifique (CNRS), International Consortium for the Environmental Implications of Nanotechnology (iCEINT), Aix en Provence, France, Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Collège de France (CdF (institution))-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Stereochemistry, Metal Nanoparticles, Nanoparticle, 02 engineering and technology, 010501 environmental sciences, 01 natural sciences, Arsenic, Adsorption, Desorption, Zeta potential, Humans, Environmental Chemistry, Surface charge, Magnetite Nanoparticles, Cytotoxicity, Cells, Cultured, Metalloids, Skin, 0105 earth and related environmental sciences, chemistry.chemical_classification, Chemistry, General Chemistry, Fibroblasts, 021001 nanoscience & nanotechnology, Culture Media, [SDE]Environmental Sciences, Biophysics, Thiol, Thermodynamics, Magnetic nanoparticles, 0210 nano-technology
Abstract

International audience; This study investigates the issue of nanoparticles/pollutants cocontamination. By combining viability assays, physicochemical and structural analysis (to probe the As speciation and valence), we assessed how gamma Fe2O3 nanoparticles can affect the cytotoxicity, the intra- and extracellular speciation of As(III). Human dermal fibroblasts were contaminated with gamma Fe2O3 nanoparticles and As(III) considering two scenarios: (i) a simultaneous coinjection of the nanoparticles and As, and (ii) an injection of the I: nanoparticles after 24 h of As adsorption in water. In both scenarios, we did not notice significant changes on the nanoparticles surface charge (zeta potential similar to -10 mV) nor hydrodynamic diameters (similar to 9.50 nm) after 24 h. We demonstrated that the coinjection of gamma Fe2O3 nanoparticles and As in the cellular media strongly affects the complexation of the intracellular As with thiol groups. This significantly increases at low doses the cytotoxicity of the As nonadsorbed at the surface of the nanoparticles. However, once As is adsorbed at the surface the desorption is very weak in the culture medium. This fraction of As strongly adsorbed at the surface is significantly less cytotoxic than As itself. On the basis of our data and the thermodynamics, we demonstrated that any disturbance of the biotransformation mechanisms by the nanoparticles (i.e., surface complexation of thiol groups with the iron atoms) is likely to be responsible for the increase of the As adverse effects at low doses.

Published
2012
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6. X-ray Absorption Fine Structure Evidence for Amorphous Zinc Sulfide as a Major Zinc Species in Suspended Matter from the Seine River Downstream of Paris, Ile-de-France, France

Author

Guillaume Morin, Fabien Maillot, Olivier Proux, Cindy Rianti Priadi, Farid Juillot, Sophie Ayrault, Isabelle Llorens, Denis Testemale, Rebecca Hochreutener, Pierre Le Pape, and Gordon E. Brown

Subjects
Geologic Sediments, Paris, 010504 meteorology & atmospheric sciences, chemistry.chemical_element, Electrons, Zinc, Sulfides, 010501 environmental sciences, 01 natural sciences, chemistry.chemical_compound, Water column, Rivers, Suspensions, Environmental Chemistry, 0105 earth and related environmental sciences, Fourier Analysis, Extended X-ray absorption fine structure, Chemistry, Water, General Chemistry, Particulates, Nitrogen, Zinc sulfide, Sulfur, 6. Clean water, X-ray absorption fine structure, Oxygen, X-Ray Absorption Spectroscopy, Zinc Compounds, Environmental chemistry, Linear Models, Microscopy, Electron, Scanning, Particulate Matter, Water Pollutants, Chemical
Abstract

Zinc is one of the most widespread trace metals (TMs) in Earth surface environments and is the most concentrated TM in the downstream section of the Seine River (France) due to significant anthropogenic input from the Paris conurbation. In order to better identify the sources and cycling processes of Zn in this River basin, we investigated seasonal and spatial variations of Zn speciation in suspended particulate matter (SPM) in the oxic water column of the Seine River from upstream to downstream of Paris using synchrotron-based extend X-ray absorption fine structure (EXAFS) spectroscopy at the Zn K-edge. First-neighbor contributions to the EXAFS were analyzed in SPM samples, dried and stored under a dry nitrogen atmosphere or under an ambient oxygenated atmosphere. We found a sulfur first coordination environment around Zn (in the form of amorphous zinc sulfide) in the raw SPM samples stored under dry nitrogen vs an oxygen first coordination environment around Zn in the samples stored in an oxygenated atmosphere. These findings are supported by scanning electron microscopy and energy dispersive X-ray spectrometry observations. Linear combination fitting of the EXAFS data for SPM samples, using a large set of EXAFS spectra of Zn model compounds, indicates dramatic changes in the Zn speciation from upstream to downstream of Paris, with amorphous ZnS particles becoming dominant dowstream. In contrast, Zn species associated with calcite (either adsorbed or incorporated in the structure) are dominant upstream. Other Zn species representing about half of the Zn pool in the SPM consist of Zn-sorbed on iron oxyhydroxides (ferrihydrite and goethite) and, to a lesser extent, Zn-Al layered double hydroxides, Zn incorporated in dioctahedral layers of clay minerals and Zn sorbed to amorphous silica. Our results highlight the importance of preserving the oxidation state in TM speciation studies when sampling suspended matter, even in an oxic water column.

Published
2012
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8. Evidence that Soil Properties and Organic Coating Drive the Phytoavailability of Cerium Oxide Nanoparticles

Author

Layet, Clément, primary, Auffan, Mélanie, additional, Santaella, Catherine, additional, Chevassus-Rosset, Claire, additional, Montes, Mélanie, additional, Ortet, Philippe, additional, Barakat, Mohamed, additional, Collin, Blanche, additional, Legros, Samuel, additional, Bravin, Matthieu N., additional, Angeletti, Bernard, additional, Kieffer, Isabelle, additional, Proux, Olivier, additional, Hazemann, Jean-Louis, additional, and Doelsch, Emmanuel, additional

Published
2017
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9. Impact of a Model Soil Microorganism and of Its Secretome on the Fate of Silver Nanoparticles

Author

Eymard-Vernain, Elise, Lelong, Cécile, Pradas del Real, Ana-Elena, Soulas, Romain, Bureau, Sarah, Tardillo Suarez, Vanessa, Gallet, Benoit, Proux, Olivier, Castillo-Michel, Hiram, and Sarret, Géraldine

Abstract

Sulfidation is a key process for silver nanoparticles released from consumer products in the environment. This study focuses on the impact of a model soil microorganism, Bacillus subtilis, on the fate of pristine and already sulfidized Ag-NPs. The nanoparticles were incubated with the initial growth medium, isolated secretome, and living bacteria, and characterized for their size and morphology, agglomeration state, structure, and Ag speciation. No Ag internalization or sorption on the cell wall was detected. A partial sulfidation, leading to an Ag–Ag2S core–shell structure, was observed in the presence of the secretome, and the rate limiting step of the reaction was the oxidation of Ag0, and it was favored near the crystal dislocations. The sulfidation was complete in the presence of the living bacteria and followed an indirect pathway. Both crystalline Ag2S and amorphous Ag2S and/or Ag-thiol were identified. At the opposite, the bacteria had no impact on Ag2S. These results suggest that microorganisms participate in the sulfidation of Ag-NPs in aerobic systems such as unsaturated soils, and thus affect the bioavailability of Ag. It is important to take these transformations into account during exposure experiments, since they drastically change the exposure conditions. Finally, the secretome of B. subtilismight be used for the green synthesis of Ag–Ag2S core–shell nanoparticles.

Published
2024
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13. X-ray Absorption Fine Structure Evidence for Amorphous Zinc Sulfide as a Major Zinc Species in Suspended Matter from the Seine River Downstream of Paris, Ile-de-France, France

Author

Priadi, Cindy, primary, Le Pape, Pierre, additional, Morin, Guillaume, additional, Ayrault, Sophie, additional, Maillot, Fabien, additional, Juillot, Farid, additional, Hochreutener, Rebecca, additional, Llorens, Isabelle, additional, Testemale, Denis, additional, Proux, Olivier, additional, and Brown, Gordon E., additional

Published
2012
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