title: Mobile uranium(IV)-bearing colloids in a mining-impacted wetland.
abstract: Tetravalent uranium is commonly assumed to form insoluble species, resulting in the immobilization of uranium under reducing conditions. Here we present the first report of mobile U(IV)-bearing colloids in the environment, bringing into question this common assumption. We investigate the mobility of uranium in a mining-impacted wetland in France harbouring uranium concentrations of up to 14,000 p.p.m. As an apparent release of uranium into the stream passing through the wetland was observable, we examine soil and porewater composition as a function of depth to assess the geochemical conditions leading to this release. The analyses show the presence of U(IV) in soil as a non-crystalline species bound to amorphous Al-P-Fe-Si aggregates, and in porewater, as a distinct species associated with Fe and organic matter colloids. These results demonstrate the lability of U(IV) in these soils and its association with mobile porewater colloids that are ultimately released into surface water.
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne (EPFL), Environmental Microbiology Laboratory (EML), EPFL-ENAC-IIE-EML, Station 6, CH-1015 Lausanne, Switzerland.
authors.forename: Yuheng
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne (EPFL), Environmental Microbiology Laboratory (EML), EPFL-ENAC-IIE-EML, Station 6, CH-1015 Lausanne, Switzerland.
authors.forename: Manon
authors.initials: M
authors.lastname: Frutschi
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne (EPFL), Environmental Microbiology Laboratory (EML), EPFL-ENAC-IIE-EML, Station 6, CH-1015 Lausanne, Switzerland.
authors.forename: Elena
authors.initials: E
authors.lastname: Suvorova
authors.affiliation: AREVA-Business Group Mines, R&D Department, BAL 0414C-2, Tour AREVA, 1, place Jean Millier, 92084 Paris La Défense Cedex, France.
authors.forename: Vannapha
authors.initials: V
authors.lastname: Phrommavanh
authors.affiliation: AREVA-Business Group Mines, R&D Department, BAL 0414C-2, Tour AREVA, 1, place Jean Millier, 92084 Paris La Défense Cedex, France.
authors.forename: Michael
authors.initials: M
authors.lastname: Descostes
authors.affiliation: Helmholtz Center Dresden Rossendorf (HZDR), Institute of Resource Ecology, Bautzener Landstraße 400, D-01328 Dresden, Germany.
authors.forename: Alfatih A A
authors.initials: AA
authors.lastname: Osman
authors.affiliation: Helmholtz Center Dresden Rossendorf (HZDR), Institute of Resource Ecology, Bautzener Landstraße 400, D-01328 Dresden, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Geipel
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne (EPFL), Environmental Microbiology Laboratory (EML), EPFL-ENAC-IIE-EML, Station 6, CH-1015 Lausanne, Switzerland.
authors.forename: Rizlan
authors.initials: R
authors.lastname: Bernier-Latmani
mesh_terms: D003102:Colloids / Q000737:chemistry*; D005602:France; D008906:Mining; D045483:Rivers / Q000737:chemistry; D012987:Soil / Q000737:chemistry; D012990:Soil Pollutants, Radioactive / Q000737:chemistry; D017974:Uranium Compounds / Q000737:chemistry*; D014875:Water Pollutants, Radioactive / Q000737:chemistry*; D053833:Wetlands
chemical_list: D003102:Colloids; D012987:Soil; D012990:Soil Pollutants, Radioactive; D017974:Uranium Compounds; D014875:Water Pollutants, Radioactive