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10. Recent advances in surface, interface, and environmental geochemistry

Author

Yoon, T, primary, Calas, G, additional, Yamamoto, S, additional, Eng, P, additional, Trainor, T, additional, Morin, G, additional, Juillot, F, additional, Bluhm, H, additional, Ona-Nguema, G, additional, Starr, D, additional, Tanwar, K, additional, Cances, B, additional, Chaka, A, additional, Nilsson, A, additional, Benzerara, K, additional, Brown, G, additional, Catalano, J, additional, Kendelewicz, T, additional, Salmeron, M, additional, and Farges, F, additional

Published
2007
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12. High-temperature structural study of germanate perovskites and pyroxenoids

Author

Andrault, D., Itie, J-P., and Farges, F.

Subjects
Perovskite -- Research, Pyroxene -- Research, Materials at high temperatures -- Research, Earth sciences
Abstract

The CaGe[O.sub.3] and SrGe[O.sub.3] perovskites and CaGe[O.sub.3], SrGe[O.sub.3], and MnGe[O.sub.3] pyroxenoids have been studied at high-temperature by X-ray diffraction (XRD) and X-ray absorption fine-structure spectroscopy (XAFS). The diffraction studies show that the back-transformation of the perovskite begins at lower temperature for SrGe[O.sub.3] ([approximately]500 K) than CaGe[O.sub.3] ([approximately] 945 K). An intensity reduction of the Bragg lines and the presence of a diffuse band in the diffraction patterns show the occurrence of transient amorphous phases. This transient phase contains Ge in fourfold and sixfold coordination after the loss of CaGe[O.sub.3] and SrGe[O.sub.3] perovskites, respectively. The recrystallization of the stable pyroxenoids occurs at higher temperature in a second step of the transformation. For these compounds, the anharmonic character of the first Ge-O bond was extracted from the XAFS analysis. For the perovskites, we observed that the bulk thermal expansion and the Ge-O bond anharmonicity are closely connected. Both parameters are higher for cubic SrGe[O.sub.3] and simultaneously increase near 525 K when CaGe[O.sub.3] changes symmetry. For the pyroxenoids, our calculated tetrahedral thermal expansion is lower than for the bulk, with Ge-O bond anharmonicity very low. Close to the melting point, anomalous motion of the tetrahedral chains is suggested by a significant increase of the Ge-O bond length.

Published
1996

13. Entrapped elemental selenium nanoparticles affect physicochemical properties of selenium fed activated sludge

Author

Jain, R., Seder-Colomina, M., Jordan, N., Dessi, P., Cosmidis, J., Hullebusch, E. D., Weiss, S., Farges, F., and Lens, P. N. L.

Subjects
inorganic chemicals, surface charge, settleability, physicochemical, food and beverages, activated sludge, nanoparticles, selenium
Abstract

Selenite containing wastewaters can be treated in activated sludge systems, where the total selenium is removed from the wastewater by the formation of elemental selenium nanoparticles, which are trapped in the biomass. No studies have been carried out so far on the characterization of selenium fed activated sludge flocs, which is important for the development of this novel selenium removal process. This study showed that more than 93% of the trapped selenium in activated sludge flocs is in the form of elemental selenium, both as amorphous/ monoclinic selenium nanospheres and trigonal selenium nanorods. The entrapment of the elemental selenium nanoparticles in the selenium fed activated sludge flocs leads to faster settling rates, higher hydrophilicity and poorer dewaterability compared to the control activated sludge (i.e. not fed with selenite). The selenium fed activated sludge showed a less negative surface charge density as compared to control activated sludge. The presence of trapped elemental selenium nanoparticles further affected the spatial distribution of Al and Mg in the activated sludge flocs. This study demonstrated that the formation and subsequent trapping of elemental selenium nanoparticles in the activated sludge flocs affects their physicochemical properties.

Published
2015

14. On the Origin of the Green Colour of Archaeological Bone Artefacts of the Gallo-Roman Period

Author

Ferrand, J., Rossano, Stéphanie, Rollet, Ph., Allard, Thierry, Cordier, P., Catillon, Gilles, Auxiette, G., Farges, F., Pont, S., Laboratoire Géomatériaux et Environnement (LGE), Université Paris-Est Marne-la-Vallée (UPEM), Institut national de recherches archéologiques préventives (Inrap), Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Unité Matériaux et Transformations - UMR 8207 (UMET), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut National de la Recherche Agronomique (INRA)

Subjects
COLOURATION PROCESS, ARTEFACT, COPPER, GREEN BONE, [SDU.OTHER]Sciences of the Universe [physics]/Other, GALLO-ROMAN
Abstract

International audience; Recent findings in the city of Reims have lead to the discovery of manufactured bone objects coloured in green throughout their entire volume. In order to discover the intentional nature of the colouration and to propose a colouration mechanism, modern ox bones have been coloured in the laboratory. Bones with a hue similar to that of the archaeological artefacts have been obtained by boiling in an acidic brine in a copper vessel. A combination of infrared spectroscopy, X-ray diffraction and transmission electron microscope observations did not reveal the speciation of copper, but allowed us to validate the colouration process and to discuss the intentional origin of the colouration.

Published
2013

16. The Browning Phenomenon of Medieval Stained Glass Windows

Author

Ferrand, J., Rossano, Stéphanie, Loisel, C., van Hullebusch, Eric D., Trcera, N., Farges, F., Orial, G., Bousta, F., Pallot-Frossard, I., Laboratoire Géomatériaux et Environnement (LGE), Université Paris-Est Marne-la-Vallée (UPEM), and Lge, Admin

Published
2012

21. On the origin of the green colour of achaeological bone artefacts of galloroman period

Author

Ferrand, J., Rossano, Stéphanie, Rollet, Ph., Farges, F., Allard, Thierry, Pont, S., Catillon, Gilles, Laboratoire Géomatériaux et Environnement (LGE), Université Paris-Est Marne-la-Vallée (UPEM), 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), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)

Published
2010

22. Oxidation state variation under beta-irradiation in Fe-bearing glass systems

Author

Rossano, Stéphanie, Jean-Soro, L., Boizot, B., Farges, F., van Hullebusch, Eric D., Labanowski, J., Linares, J., C. Swarbrick, J., Harfouche, M., Laboratoire Géomatériaux et Environnement (LGE), Université Paris-Est Marne-la-Vallée (UPEM), Laboratoire de Chimie et Microbiologie de l'Eau (LCME), Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut de Chimie du CNRS (INC), Groupe d'Etude de la Matière Condensée (GEMAC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), and Université de Poitiers-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM]Chemical Sciences
Published
2010

23. Investigation of Sulfur chemical state in anaerobic granular biofilms : a Sulfur K-edge XANES Spectroscopy study

Author

van Hullebusch, Eric D., Farges, F., Lenz, M., Labanowski, J., Lagarde, P., Flank, A.-M., Lens, P., Laboratoire Géomatériaux et Environnement (LGE), Université Paris-Est Marne-la-Vallée (UPEM), Laboratoire de Chimie et Microbiologie de l'Eau (LCME), Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut de Chimie du CNRS (INC), and Université de Poitiers-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM]Chemical Sciences
Published
2010

25. Speciation of heavy metal association with particulate organic matter in contaminated agrosystems : a XAFS study

Author

Labanowski, J., Farges, F., Van Hullebusch, Eric D., Harfouche, M., Van Oort, F., Borca, C., Laboratoire de Chimie et Microbiologie de l'Eau (LCME), Université de Poitiers-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Géomatériaux et Environnement (LGE), Université Paris-Est Marne-la-Vallée (UPEM), and Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut de Chimie du CNRS (INC)

Subjects
[CHIM]Chemical Sciences
Published
2009

26. Mechanisms of Zn bioavailability related to speciation of metal-particulate organic matter associations in polluted soils

Author

Harfouche, M., jérôme Labanowski, Farges, F., Hullebusch, Eric D., Oort, F., Borca, C., Laboratoire de Chimie et Microbiologie de l'Eau (LCME), Université de Poitiers-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Géomatériaux et Environnement (LGE), Université Paris-Est Marne-la-Vallée (UPEM), and Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut de Chimie du CNRS (INC)

Subjects
[CHIM]Chemical Sciences, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2009

29. Sulfur K-edge XANES spectroscopy as a tool for understanding sulfur chemical state in anaerobic granular sludge

Author

Van Hullebusch, E. Rossano, S. Farges, F. Lenz, M. Labanowski, J. Lagarde, P. A. M. Flank Lens, P.

Subjects
anaerobic granular sludge, biochemistry, wastewater treatment, sulphur
Abstract

Sulfur is an essential biological element, yet its biochemistry in anaerobic biofilm is poorly understood because there are few tools for studying this element in biological systems. X-ray absorption spectroscopy provides a unique approach to determining the chemical speciation of sulfur in intact biological samples. When treating sulfate containing wastewaters in full scale up-flow anaerobic sludge bed bioreactors, microbial activity forms biofilms, consisting of a complex mixture of cells and associated extracellular substances as well as undefined inorganic precipitates. In addition to the anaerobic sludges, a large variety of model compounds of S (esp. sulfides) were investigated to find consistencies in the XANES that were used to model each ”valence state” of S. The results confirmed that attributing a specific valence to most sulfides is impossible as we measured a continuum of edge shifts from sulfur ”–2” to ”–1”, depending on the electronic structure of S in the probed sulfides. In the sludges, various sulfur hot spots were probed for speciation, despite photo-reduction was sometimes a problem. First, we index the main features of complex K-edge XANES spectra for S2units and sulfate units. Organic sulfur compounds were also shown to contribute significantly to the sulfur species present in some anaerobic granular sludge

Published
2009

33. Microbial biomineralization and redox transformation of As and Fe in an acid mine drainage

Author

Benzerara, K., Morin, G., Yoon, T. H., Miot, J., Casiot, C., Farges, F., Brown, G. E., Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Hydrosciences Montpellier (HSM), Institut de Recherche pour le Développement (IRD)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), 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 national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2007

34. Local structures around Si, Al, and Na in hydrated silicate glasses

Author

Farges, F., de Wispelaere, S., Rossano, Stéphanie, Munoz, M., Wilke, M., Flank, A.-M., Laboratoire Géomatériaux et Environnement (LGE), Université Paris-Est Marne-la-Vallée (UPEM), and Lge, Admin

Subjects
ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2006

36. A Focus on Chemical and Microbial Processes at Environmental Interfaces

Author

Brown, Jr-G.E., Nilsson, A., Spormann, A.M., P. Addiego, W., Benzerara, K., Bergmann, U., Bluhm, H., A. Brown, B., Calas, G., Chaka, A.M, Constantz, B.R., Farges, F., E. Fendorf, S., Foster, A.L., Juillot, F., Morin, G., S.C.B., M., Pettersson, L.G.M., Rosso, K.M., Rytuba, J.J., Salmeron, M., Saltzman, J., Toney, M., Trainor, T.P., Yoon, T., Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), and Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2006

41. Tin and niobium in dry and fluid-rich (H2O, F) silicate glasses

Author

Piilonen, P. C., Farges, F., Linnen, R. L., Brown, G. E., Géomatériaux et géologie de l'ingénieur (G2I), and Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-CLASS-PH]Physics [physics]/Physics [physics]/Classical Physics [physics.class-ph]
Abstract

International audience; The speciation of niobium and tin in 29 silicate glasses was investigated by XAFS at the Nb and Sn K-edges using beamline 4-3 and 11-2 at SSRL (Stanford, USA). The metal content in the glasses varies between 100 ppm and 5wt.% ( to examine the effects of Nb2O5 and SnO2 saturation in the melt composition prior quenching). The glasses show variation in composition from peralkaline to peraluminous, with either zero or similar to 2 wt.% fluorine. In addition, hydrous glasses were quenched from water-saturated melts at 850 degrees C and 2 kbar under relatively reducing conditions. Three "haplogranitic" compositions (a model granite in the system Na2O-K2O-AlO3-SiO2) were investigated: peralkaline (labeled "ASI 0.6"), metaluminous ("ASI 1.0") and peraluminous ("ASI 1.2"). One series of haplogranitic glasses ("SQ") were synthesized at intermediate oxygen fugacity conditions (similar to 10(-9) atm.). In addition, 15 model oxide and silicate compounds of tin and niobium were investigated. The tin-bearing glasses show Sn K-edge XAFS spectra that resemble that displayed by eakerite, a Ca-Sn silicate in which Sn(IV)O-6 octahedra share corners with SiO4 tetrahedra (< Sn-O-Si >: 150 degrees). However, the most reduced glasses show significant contributions arising from weakly bound Sn(II)O-n complexes. The niobium-bearing glasses show Nb K-edge XAFS spectra that most closely resemble that displayed by vuonnemite, a Na-Ti-Nb silicophosphate. Niobium forms NbO6 clusters, also bonded to Si/Al second neighbors. The coordination geometry of niobium in the glasses is strongly influenced by both Nb content and alkalinity; H2O content does not strongly influence the speciation of niobium. Fluorine-bearing Nb-glasses show unusual XANES spectra, which might be related to a decrease in the coordination number of niobium from 6 to 4 (or 5). However, based on Nb K-edge XANES calculations (FEFF 8), fluorine does not appear to complex niobium.

Published
2005

42. The Fourier-transform analysis of TiK-XANES in metamicts and glasses

Author

Bugaev, L., Farges, F., Rusakova, E., Sokolenko, A., Latokha, Ya, Avakyan, L., Géomatériaux et géologie de l'ingénieur (G2I), and Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-CLASS-PH]Physics [physics]/Physics [physics]/Classical Physics [physics.class-ph]
Abstract

International audience; The structural parameters of Ti coordination environment in glassy titanite (CaTiSiO5), natisite (Na2TiSiO5) and radiation damaged CaTiSiO5 are determined by the method proposed earlier, based on the Fourier-transform analysis of Ti K-XANES over the short k-range of photoelectrons wave numbers. The accuracy of the determined parameters is tested for the model crystals CaTiSiO5, Na2TiSiO5. The modelling of the extracted contribution into Ti-XANES, arising from the oxygen-polyhedron around the ionised Ti atom in amorphous titanites and natisite, performed via the single-shell fit and the two-shells fit, returns not only the averaged structural parameters, but also reveals the main groups of the Ti-O distances for this polyhedron.

Published
2005

44. Iron in silicate glasses: spectroscopy and simulations

Author

Farges, F., Rossano, Stéphanie, Laboratoire Géomatériaux et Environnement (LGE), Université Paris-Est Marne-la-Vallée (UPEM), and Lge, Admin

Subjects
ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2004

50. Bond valence in silicate glasses

Author

Rossano, Stéphanie, Farges, F., Ramos, A, Delaye, JM, Brown, Ge, Laboratoire Géomatériaux et Environnement (LGE), Université Paris-Est Marne-la-Vallée (UPEM), and Lge, Admin

Subjects
[SPI.MAT] Engineering Sciences [physics]/Materials, [SPI.MAT]Engineering Sciences [physics]/Materials
Abstract

International audience; In contrast with crystals, glass structure cannot be unambiguously determined by experimental techniques, and molecular dynamics (MD) simulations are often used to model such systems. Ion-ion interactions are modeled by empirical potentials, which are validated by comparison between the structural information extracted from experimental results and the simulated structure. Bond valence (BV) theory is often used to check the reliability of experimentally determined crystal structures. However, it has not been applied in a similar fashion to the results of MD simulations of disordered systems. To illustrate the use of BV theory in silicate glasses, BV calculations were performed in a 1500 atom-3D-periodic MD simulation box of a glass of composition CaO-FeO-2SiO(2) (mol%) with two sets of Born-Mayer-Huggins potentials. The structural models are analyzed from the point of view of BV theory. The BV sums around the 1500 atoms show that the BV model is globally verified. In addition, we show that the BV sums are sensitive to changes in MD potential parameters and can thus be used to test the plausibility of the MD model of a silicate glass. This new strategy opens possibilities in the derivation of more robust and constrained structural models of silicate glasses and melts. (C) 2002 Elsevier Science B.V. All rights reserved.

Published
2002

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