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Title: Effect of fulvic acid surface coatings on plutonium sorption and desorption kinetics on goethite

The rates and extent of plutonium (Pu) sorption and desorption onto mineral surfaces are important parameters for predicting Pu mobility in subsurface environments. The presence of natural organic matter, such as fulvic acid (FA), may influence these parameters. We investigated the effects of FA on Pu(IV) sorption/desorption onto goethite in two scenarios: when FA was (1) initially present in solution or (2) found as organic coatings on the mineral surface. A low pH was used to maximize FA coatings on goethite. Experiments were combined with kinetic modeling and speciation calculations to interpret variations in Pu sorption rates in the presence of FA. Our results indicate that FA can change the rates and extent of Pu sorption onto goethite at pH 4. Differences in the kinetics of Pu sorption were observed as a function of the concentration and initial form of FA. The fraction of desorbed Pu decreased in the presence of FA, indicating that organic matter can stabilize sorbed Pu on goethite. These results suggest that ternary Pu–FA–mineral complexes could enhance colloid-facilitated Pu transport. In conclusion, more representative natural conditions need to be investigated to quantify the relevance of these findings.
 [1] ;  [2] ;  [2] ;  [3] ;  [4] ;  [4] ;  [2] ;  [2]
  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  3. Colorado School of Mines, Golden, CO (United States)
  4. Clemson Univ., Clemson, SC (United States)
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 0013-936X
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Environmental Science and Technology
Additional Journal Information:
Journal Volume: 49; Journal Issue: 5; Journal ID: ISSN 0013-936X
American Chemical Society (ACS)
Research Org:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY plutonium; fulvic acid; natural organic matter; sorption; desorption; surface coating; kinetics