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Mechanistic Understanding of Uranyl Ion Complexation on Montmorillonite Edges: A Combined First-Principles Molecular Dynamics–Surface Complexation Modeling Approach

Journal Article · · Environmental Science and Technology
 [1];  [2];  [3];  [4]
  1. Nanjing Univ. (China); California State University East Bay
  2. Nanjing Univ. (China)
  3. California State Univ., East Bay, Hayward, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  4. California State Univ., East Bay, Hayward, CA (United States); BRGM, Orléans (France); Univ. Orléans (France); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
+ Show Author Affiliations
Systematic first-principles molecular dynamics (FPMD) simulations were carried out to study the structures, free energies, and acidity constants of UO22+ surface complexes on montmorillonite in order to elucidate the surface complexation mechanisms of the uranyl ion (UO22+) on clay mineral edges at the atomic scale. Four representative complexing sites were investigated, that is, ≡Al(OH)2 and ≡AlOHSiO on the (010) surface and ≡AlOHOa and ≡SiOOa on the (110) surface. The results show that uranyl ions form bidentate complexes on these sites. We report all calculated binding free energies for these complexes are very similar. These bidentate complexes can be hydrolyzed, and their corresponding derived pKa values (around 5.0 and 9.0 for pKa1 and pKa2, respectively) indicate that UO2(OH)+ and UO2(OH)2 surface groups are the dominant surface species in the environmental pH range. The OH groups of UO2(OH)2 surface complexes can act as complexing sites for subsequent metals. Additional simulations showed that such multinuclear adsorption is feasible and can be important at high pH. Furthermore, FPMD simulation results served as input parameters for an electrostatic thermodynamic surface complexation model (SCM) that adequately reproduced adsorption data from the literature. Overall, this study provides an improved understanding of UO22+ complexation on clay mineral edge surfaces.
Research Organization:
California State Univ., East Bay, Hayward, CA (United States)
Sponsoring Organization:
USDOE Office of Nuclear Energy (NE); National Natural Science Foundation of China (NSFC)
DOE Contract Number:
NE0008683
OSTI ID:
1595740
Journal Information:
Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 15 Vol. 52; ISSN 0013-936X
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English

References (74)

U(VI) sorption on montmorillonite in the absence and presence of carbonate: A macroscopic and microscopic study journal September 2012
Surface complexation of heavy metal cations on clay edges: insights from first principles molecular dynamics simulation of Ni(II) journal April 2017
The structure of monomeric and dimeric uranyl adsorption complexes on gibbsite: A combined DFT and EXAFS study journal October 2009
First-Principles Modeling of Mn(II) Migration above and Dissolution from Li x Mn 2 O 4 (001) Surfaces journal November 2016
RETRACTED: The retention of uranium and europium onto sepiolite investigated by macroscopic, spectroscopic and modeling techniques journal September 2014
Separable dual-space Gaussian pseudopotentials journal July 1996
Zinc Adsorption on Clays Inferred from Atomistic Simulations and EXAFS Spectroscopy journal May 2012
Water Structure and Hydrogen Bonding at Goethite/Water Interfaces: Implications for Proton Affinities journal February 2012
Understanding surface acidity of gibbsite with first principles molecular dynamics simulations journal November 2013
Water Structure and Aqueous Uranyl(VI) Adsorption Equilibria onto External Surfaces of Beidellite, Montmorillonite, and Pyrophyllite:  Results from Molecular Simulations journal June 2006
Quickstep: Fast and accurate density functional calculations using a mixed Gaussian and plane waves approach journal April 2005
Cadmium(II) Complexes Adsorbed on Clay Edge Surfaces: Insight From First Principles Molecular Dynamics Simulation journal August 2016
Structural characterization of U(VI) surface complexes on kaolinite in the presence of humic acid using EXAFS spectroscopy journal March 2008
Acidity of edge surface sites of montmorillonite and kaolinite journal September 2013
Modeling the Acid–Base Properties of Montmorillonite Edge Surfaces journal November 2016
Sorption of Heavy Metal Ions from Aqueous Solutions: A Review journal April 2011
Atomic-scale structures of interfaces between phyllosilicate edges and water journal March 2012
Surface complexation of Pb(II) by hexagonal birnessite nanoparticles journal December 2010
Interfacial structures and acidity of edge surfaces of ferruginous smectites journal November 2015
Adsorption of Uranium(VI) to Manganese Oxides: X-ray Absorption Spectroscopy and Surface Complexation Modeling journal December 2012
Modelling the sorption of Mn(II), Co(II), Ni(II), Zn(II), Cd(II), Eu(III), Am(III), Sn(IV), Th(IV), Np(V) and U(VI) on montmorillonite: Linear free energy relationships and estimates of surface binding constants for some selected heavy metals and actinides journal February 2005
Free energy from constrained molecular dynamics journal November 1998
Structure of uranium sorption complexes at montmorillonite edge sites journal September 2002
Thermodynamically Consistent Force Field for Molecular Dynamics Simulations of Alkaline-Earth Carbonates and Their Aqueous Speciation journal October 2015
Gaussian basis sets for accurate calculations on molecular systems in gas and condensed phases journal September 2007
Acidity of the Aqueous Rutile TiO 2 (110) Surface from Density Functional Theory Based Molecular Dynamics journal February 2010
Redox potentials and pKa for benzoquinone from density functional theory based molecular dynamics journal October 2009
Mineral–Water Interface Reactions of Actinides journal October 2012
RETRACTED: Adsorption of U(VI) on sericite in the presence of Bacillus subtilis: A combined batch, EXAFS and modeling techniques journal May 2016
Uranyl adsorption at solvated edge surfaces of 2 : 1 smectites. A density functional study journal January 2015
Nanoscale Size Effects on Uranium(VI) Adsorption to Hematite journal March 2009
The oxidation of tyrosine and tryptophan studied by a molecular dynamics normal hydrogen electrode journal June 2011
Uranyl sorption onto gibbsite studied by time-resolved laser-induced fluorescence spectroscopy (TRLFS) journal October 2005
The influence of temperature and density functional models in ab initio molecular dynamics simulation of liquid water journal January 2005
Coordination numbers as reaction coordinates in constrained molecular dynamics journal January 1998
The Speciation of Uranium in a Smectite Clay: Evidence for Catalysed Uranyl Reduction journal February 1997
Complexation of heavy metal cations on clay edges at elevated temperatures journal February 2018
Uranyl adsorption at (010) edge surfaces of kaolinite: A density functional study journal February 2011
Predictive sorption modelling of Ni(II), Co(II), Eu(IIII), Th(IV) and U(VI) on MX-80 bentonite and Opalinus Clay: A “bottom-up” approach journal April 2011
Andra thermodynamic database for performance assessment: ThermoChimie journal October 2014
The Silica–Water Interface: How the Silanols Determine the Surface Acidity and Modulate the Water Properties journal February 2012
Toward a Reliable Energetics of Adsorption at Solvated Mineral Surfaces: A Computational Study of Uranyl(VI) on 2:1 Clay Minerals journal December 2015
Uranyl sorption by smectites: spectroscopic assessment of thermodynamic modeling journal September 2004
An EXAFS study of uranyl ion in solution and sorbed onto silica and montmorillonite clay colloids journal April 1992
Periodic density functional theory calculations of bulk and the (010) surface of goethite journal May 2008
Effect of phosphate on U(VI) sorption to montmorillonite: Ternary complexation and precipitation barriers journal February 2016
Uranyl adsorption on solvated edge surfaces of pyrophyllite: a DFT model study journal January 2012
Surface-charge properties and UO22+ adsorption of a subsurface smectite journal September 1996
Sorption Speciation of Lanthanides/Actinides on Minerals by TRLFS, EXAFS and DFT Studies: A Review journal November 2010
Speciation of uranyl sorbed at multiple binding sites on montmorillonite journal September 1994
Surface acidity of 2:1-type dioctahedral clay minerals from first principles molecular dynamics simulations journal September 2014
Clays in radioactive waste disposal journal May 2010
Generalized Gradient Approximation Made Simple journal October 1996
A hybrid Gaussian and plane wave density functional scheme journal October 1997
Lead and selenite adsorption at water–goethite interfaces from first principles journal August 2017
Modeling uranium(VI) adsorption onto montmorillonite under varying carbonate concentrations: A surface complexation model accounting for the spillover effect on surface potential journal January 2018
Absolute acidity of clay edge sites from ab-initio simulations journal October 2012
Ab Initio Molecular Dynamics book January 2009
Modeling specific pH dependent sorption of divalent metals on montmorillonite surfaces. A review of pitfalls, recent achievements and current challenges journal May 2013
Use of 234 U and 238 U isotopes to evaluate contamination of near-surface groundwater with uranium-mill effluent: a case study in south-central Colorado, U.S.A. journal September 1997
Insights into the Mechanism of Fe(II) Adsorption and Oxidation at Fe–Clay Mineral Surfaces from First-Principles Calculations journal October 2013
Uranyl adsorption onto montmorillonite: Evaluation of binding sites and carbonate complexation journal June 2005
Ab initio molecular dynamics study of the interlayer and micropore structure of aqueous montmorillonite clays journal November 2015
Hydrolysis of Uranium(VI) at Variable Temperatures (10−85 °C) journal May 2004
Molecular simulation of the magnetite-water interface journal March 2003
Acidity constants from DFT-based molecular dynamics simulations journal June 2010
Acidity constants from vertical energy gaps: density functional theory based molecular dynamics implementation journal January 2008
Use of Spectroscopic Techniques for Uranium(VI)/Montmorillonite Interaction Modeling journal March 2004
Fluorescence spectroscopy of U(VI)-silicates and U(VI)-contaminated Hanford sediment journal March 2005
Clay minerals in the Meuse-Haute Marne underground laboratory (France): Possible influence of organic matter on clay mineral evolution journal October 2004
Acidity constants and redox potentials of uranyl ions in hydrothermal solutions journal January 2016
The structure of uranium (VI) sorption complexes on silica, alumina, and montmorillonite journal July 2000
Uranium(6+) sorption on montmorillonite: Experimental and surface complexation modeling study journal September 1996
Uranium Uptake by Hectorite and Montmorillonite: A Solution Chemistry and Polarized EXAFS Study journal October 2009

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Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
Adsorption
Cations
Complexation
Ions
Montmorillonite