Mechanisms of plutonium sorption to mineral oxide surfaces: new insights with implications for colloid-enhanced migration Conference Paper uri icon


  • Abstract New equilibrium and kinetic models have been developed to describe rate-limited sorption and desorption of Pu onto and off of mineral oxide surfaces using a generic approach to estimate sorption constants that require minimal laboratory calibrations. Equilibrium reactions describing a total of six surface species were derived from a combination of empirical relationships previously described in the literature and generated as part of this work. These sorption reactions and corresponding equilibrium constants onto goethite (and silica) are: SOH + Pu3+ SOPu2+ + H+,logK = 2.1(10)(1) SOH + Pu4+ SOPu3+ + H+,logK = 15.3(7.2)(2) SOH + PuO2 + SOPuO2 + H+,logK = 8.5(16.5)(3) SOH + PuO2 2+ SOPuO2 + + H+,logK = 1.2(6.5)(4) SOH + Pu4+ + 3H2O SOPu(OH)3 + 4H+,logK = 12.5(4.6)(5) SOH + Pu4+ + 4H2O SOPu(OH)4 + 5H+,logK = 5.0(2.3)(6) The kinetic model decouples reduced (III, IV) and oxidized (V, VI) forms of Pu via a single rate-limiting, but reversible, surface mediated reaction:...

published proceedings


author list (cited authors)

  • Schwantes, J. M., & Santschi, P. H.

citation count

  • 5

complete list of authors

  • Schwantes, JM||Santschi, PH

publication date

  • November 2010