skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

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

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 L III-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 monodentate U(IV)-carboxyl complexes. Such a U redistribution from U-minerals inherited from mine water discharge deposits could result from redox cycling nearby the water table fluctuation zone. In conclusion, oxidative dissolution of U(IV)-phosphate minerals could have led to U(VI)-organic matter complexation, followed by subsequent reduction into U(IV)-organic complexes. However, uranium(IV) minerals could havemore » been preserved in permanently waterlogged soil.« less

Authors:
 [1];  [2]; ORCiD logo [2];  [3];  [3];  [3];  [3];  [2];  [4];  [5]; ORCiD logo [5];  [2]; ORCiD logo [3]
  1. CNRS-Sorbonne Univ.-IRD-MNHN, Paris Cedex (France); Institut de Radioprotection et de Surete Nucleaire, Fontenay-aux-Roses (France)
  2. Institut de Radioprotection et de Surete Nucleaire, Fontenay-aux-Roses (France)
  3. CNRS-Sorbonne Univ.-IRD-MNHN, Paris Cedex (France)
  4. Univ. Grenoble Alpes, Grenoble (France); BM30B/CRG-FAME, ESRF, Grenoble (France)
  5. SLAC National Accelerator Lab., Menlo Park, CA (United States)
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1490871
Grant/Contract Number:  
AC02-76SF00515
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Environmental Science and Technology
Additional Journal Information:
Journal Volume: 52; Journal Issue: 22; Journal ID: ISSN 0013-936X
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES

Citation Formats

Stetten, Lucie, Blanchart, Pascale, Mangeret, Arnaud, Lefebvre, Pierre, Le Pape, Pierre, Brest, Jessica, Merrot, Pauline, Julien, Anthony, Proux, Olivier, Webb, Samuel M., Bargar, John R., Cazala, Charlotte, and Morin, Guillaume. Redox Fluctuations and Organic Complexation Govern Uranium Redistribution from U(IV)-Phosphate Minerals in a Mining-Polluted Wetland Soil, Brittany, France. United States: N. p., 2018. Web. doi:10.1021/acs.est.8b03031.
Stetten, Lucie, Blanchart, Pascale, Mangeret, Arnaud, Lefebvre, Pierre, Le Pape, Pierre, Brest, Jessica, Merrot, Pauline, Julien, Anthony, Proux, Olivier, Webb, Samuel M., Bargar, John R., Cazala, Charlotte, & Morin, Guillaume. Redox Fluctuations and Organic Complexation Govern Uranium Redistribution from U(IV)-Phosphate Minerals in a Mining-Polluted Wetland Soil, Brittany, France. United States. doi:10.1021/acs.est.8b03031.
Stetten, Lucie, Blanchart, Pascale, Mangeret, Arnaud, Lefebvre, Pierre, Le Pape, Pierre, Brest, Jessica, Merrot, Pauline, Julien, Anthony, Proux, Olivier, Webb, Samuel M., Bargar, John R., Cazala, Charlotte, and Morin, Guillaume. Fri . "Redox Fluctuations and Organic Complexation Govern Uranium Redistribution from U(IV)-Phosphate Minerals in a Mining-Polluted Wetland Soil, Brittany, France". United States. doi:10.1021/acs.est.8b03031.
@article{osti_1490871,
title = {Redox Fluctuations and Organic Complexation Govern Uranium Redistribution from U(IV)-Phosphate Minerals in a Mining-Polluted Wetland Soil, Brittany, France},
author = {Stetten, Lucie and Blanchart, Pascale and Mangeret, Arnaud and Lefebvre, Pierre and Le Pape, Pierre and Brest, Jessica and Merrot, Pauline and Julien, Anthony and Proux, Olivier and Webb, Samuel M. and Bargar, John R. and Cazala, Charlotte and Morin, Guillaume},
abstractNote = {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 monodentate U(IV)-carboxyl complexes. Such a U redistribution from U-minerals inherited from mine water discharge deposits could result from redox cycling nearby the water table fluctuation zone. In conclusion, oxidative dissolution of U(IV)-phosphate minerals could have led to U(VI)-organic matter complexation, followed by subsequent reduction into U(IV)-organic complexes. However, uranium(IV) minerals could have been preserved in permanently waterlogged soil.},
doi = {10.1021/acs.est.8b03031},
journal = {Environmental Science and Technology},
issn = {0013-936X},
number = 22,
volume = 52,
place = {United States},
year = {2018},
month = {10}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on October 19, 2019
Publisher's Version of Record

Save / Share: