Mine Water and the Environment

, Volume 28, Issue 2, pp 84–93 | Cite as

Comparing Approaches for Simulating the Reactive Transport of U(VI) in Ground Water

  • Gary P. Curtis
  • Matthias Kohler
  • James A. Davis
Technical Article


The reactive transport of U(VI) in a well-characterized shallow alluvial aquifer at a former U(VI) mill located near Naturita, CO, was predicted for comparative purposes using a surface complexation model (SCM) and a constant Kd approach to simulate U(VI) adsorption. The ground water at the site had U(VI) concentrations that ranged from 0.01 to 20 µM, alkalinities that ranged from 2.5 to 18 meq/L, and a nearly constant pH of 7.1. The SCM used to simulate U(VI) adsorption was previously determined independently using laboratory batch adsorption experiments. Simulations obtained using the SCM approach were compared with simulations that used a constant Kd approach to simulate adsorption using previously determined site-specific Kd values. In both cases, the ground water flow and transport models used a conceptual model that was previously calibrated to a chloride plume present at the site. Simulations with the SCM approach demonstrated that the retardation factor varied temporally and spatially because of the differential transport of alkalinity and dissolved U(VI) and the nonlinearity of the U(VI) adsorption. The SCM model also simulated a prolonged slow decline in U(VI) concentration, which was not simulated using a constant Kd model. Simulations using the SCM approach and the constant Kd approach were similar after 20 years of transport but diverged significantly after 60 years. The simulations demonstrate the need for site-specific geochemical information on U(VI) adsorption to produce credible simulations of future transport.


Reactive transport Uranium Environmental geochemistry Geochemical modeling 


  1. Abdelouas A, Lutze W, Nuttall HE (1999) Uranium contamination in the subsurface: characterization and remediation. In: Uranium: mineralogy, geochemistry and the environment. Reviews in Mineralogy Series, vol 38. Mineralogical Society of America, Washington, pp 433–473Google Scholar
  2. Barnett MO, Jardine PM, Brooks SC (2002) U(VI)adsorption to heterogeneous subsurface media: application of a surface complexation model. Environ Sci Technol 36(5):937–942CrossRefGoogle Scholar
  3. Bernhard G, Geipel G, Reich T, Brendler V, Amayri S, Nitsche H (2001) Uranyl(VI) carbonate complex formation: validation of the Ca2UO2(CO3)3 (aq) species. Radiochim Acta 89(8):511–518CrossRefGoogle Scholar
  4. Bethke CM, Brady PV (2000) How the Kd approach undermines ground water cleanup. Ground Water 38(3):435–443CrossRefGoogle Scholar
  5. Crowley KD, Ahearne JF (2002) Managing the environmental legacy of U.S. nuclear weapons production. Am Sci 90:514–523Google Scholar
  6. Curtis GP (2005) Documentation and applications of the reactive geochemical transport model, RATEQ. Draft report for comment, Report NUREG/CR-6871, US Nuclear Regulatory Commission, Rockville, MD, USAGoogle Scholar
  7. Curtis GP, Davis JA (2006) Tests of Uranium (VI) Adsorption Models in a Field Setting. Report NUREG/CR-6911, US Nuclear Regulatory Commission, Rockville, MD, USAGoogle Scholar
  8. Curtis GP, Fox P, Kohler M, Davis JA (2004) Comparison of field uranium Kd values with a laboratory determined surface complexation model. Appl Geochem 19(10):1643–1653CrossRefGoogle Scholar
  9. Curtis GP, Davis JA, Naftz DL (2006) Simulation of reactive transport of uranium(VI) in ground water with variable chemical conditions. Water Resour Res 42(4):W04404. doi:10.1029/2005WR003979 CrossRefGoogle Scholar
  10. Davis JA, Curtis GP (2003) Application of Surface complexation modeling to describe Uranium(VI) adsorption and retardation at the uranium mill tailings site at Naturita, Colorado. Report NUREG CR-6820, US Nuclear Regulatory Commission, Rockville, MD, USAGoogle Scholar
  11. Davis JA, Kent DB (1990) Surface complexation modeling in aqueous geochemistry. In: Mineral–water interface geochemistry. Reviews in mineralogy, vol 23. Mineralogical Society of America, Washington, pp 177–260Google Scholar
  12. Davis JA, Coston JA, Kent DB, Fuller CC (1998) Application of the surface complexation concept to complex mineral assemblages. Environ Sci Technol 32(19):2820–2828CrossRefGoogle Scholar
  13. Davis JA, Payne TE, Waite TD (2002) Simulating the pH and pCO2 dependence of uranium(VI) adsorption by a weathered schist with surface complexation models. In: Geochemistry of soil radionuclides. Soil Science Society of America. Madison, pp 61–86Google Scholar
  14. Davis JA, Meece DM, Kohler M, Curtis GP (2004) Approaches to surface complexation modeling of uranium(VI) adsorption on aquifer sediments. Geochim Cosmochim Acta 68(18):3621–3641CrossRefGoogle Scholar
  15. Davis JA, Curtis GP, Wilkins MJ, Kohler M, Fox PM, Naftz DL, Lloyd JR (2006) Processes affecting transport of uranium in a suboxic aquifer. Phys Chem Earth 31(10–14):548–555Google Scholar
  16. Fox PM, Davis JA, Zachara JM (2006) The effect of calcium on aqueous uranium (VI) speciation and adsorption to ferrihydrite and quartz. Geochim Cosmochim Acta 70(6):1379–1387CrossRefGoogle Scholar
  17. Glynn PD (2003) Modeling Np and Pu transport with a surface complexation model and spatially variant sorption capacities: implications for reactive transport modeling and performance assessments of nuclear waste disposal sites. Comput Geosci 29(3):331–349CrossRefGoogle Scholar
  18. Grenthe I, Fuger J, Konings RJM, Lemire RJ, Muller AJ, Nguyen-Trung C, Wanner H (1992) Chemical thermodynamics of uranium. In: Wanner H, Forest I (eds) Elsevier, Amsterdam, p 735Google Scholar
  19. Gu BH, Wu WM, Ginder-Vogel MA, Yan H, Fields MW, Zhou J, Fendorf S, Criddle CS, Jardine PM (2005) Bioreduction of uranium in a contaminated soil column. Environ Sci Technol 39(13):4841–4847CrossRefGoogle Scholar
  20. Harbaugh AW, Banta ER, Hill MC, McDonald MG (2000) MODFLOW-2000, the U.S. geological survey modular ground-water model—user guide to modularization concepts and the ground-water flow process. US Geological Survey OFR 00-92, pp 121Google Scholar
  21. Kalmykov SN, Choppin GR (2000) Mixed Ca2+/UO2 2+/CO3 2− complex formation at different ionic strengths. Radiochim Acta 88(9–11):603–606CrossRefGoogle Scholar
  22. Kaplan DI, Kutnyakov IV, Gamerdinger AP, Serne RJ, Parker KE (2000) Gravel-corrected Kd values. Ground Water 38(6):851–857CrossRefGoogle Scholar
  23. Kent DB, Abrams RH, Davis JA, Coston JA, LeBlanc DR (2000) Modeling the influence of variable pH on the transport of zinc in a contaminated aquifer using semi-empirical surface complexation models. Water Resour Res 36(12):3411–3425CrossRefGoogle Scholar
  24. Kent DB, Wilkie JA, Davis JA (2007) Modeling the movement of a pH perturbation and its impact on adsorbed zinc and phosphate in a wastewater-contaminated aquifer. Water Resour Res 43(7):W07440. doi:10.1029/2005WR004841 CrossRefGoogle Scholar
  25. Kent DB, Davis JA, Joye JL, Curtis GP (2008) Influence of variable chemical conditions on EDTA-enhanced transport of metal ions in mildly acid ground water. Environ Pollut 153(1):44–52CrossRefGoogle Scholar
  26. Kohler M, Curtis GP, Kent DB, Davis JA (1996) Experimental investigation and modeling of uranium(VI) transport under variable chemical conditions. Water Resour Res 32(12):3539–3551CrossRefGoogle Scholar
  27. Kohler M, Meece DM, Curtis GP, Davis JA (2004) Methods for estimating adsorbed uranium(VI) and distribution coefficients in contaminated sediments. Environ Sci Technol 38(1):240–247CrossRefGoogle Scholar
  28. Krupka KM, Kaplan DI, Whelan G, Serne RJ, Mattigod SV (1999) Understanding variation in partition coefficient, K d values. The K d model, methods of measurements and application of chemical reaction codes. Review of geochemistry and available K d values for cadmium, cesium, chromium, lead, plutonium, radon, strontium, thorium, tritium (3H), and uranium, vol II, US Environmental Protection Agency 402-R-99-004B, p 209Google Scholar
  29. Langmuir D (1997) Aqueous environmental chemistry. Prentice-Hall, Upper Saddle River, p 600Google Scholar
  30. McFadden K, Brosseau DA, Beyeler WE, Updegraff CD (2001) Residual Radioactive Contamination from Decommissioning. User’s Manual, DandD Version 2.1, NUREG/CR-5512, vol 2 (SAND2001-0822P)Google Scholar
  31. Pabalan RT, Turner DR, Bertetti FP, Prikryl JD (1998) Uranium(VI) sorption onto selected mineral surfaces: key geochemical parameters. In: Jenne E (ed) Adsorption of metals by geomedia. Academic Press, San Diego, pp 99–130CrossRefGoogle Scholar
  32. Rubin Y (2003) Applied stochastic hydrogeology. Oxford University Press, New York, p 391Google Scholar
  33. Rubin Y, Hubbard S (2005) Hydrogeophysics. Water and science technology library 50. Springer, Netherlands, p 523Google Scholar
  34. Um W, Serne RJ, Krupka KM (2007a) Surface complexation modeling of U(VI) sorption to Hanford sediment with varying geochemical conditions. Environ Sci Technol 41(10):3587–3592CrossRefGoogle Scholar
  35. Um W, Serne RJ, Brown CF, Last GV (2007b) U(VI) adsorption on aquifer sediments at the Hanford site. J Contam Hydrol 93(1–4):255–269CrossRefGoogle Scholar
  36. USDOE (1996) Programmatic environmental impact statement for the uranium mill tailings remedial action ground water Project. DOE/EIS-0198, vol I, US Department of Energy, Grand Junction, CO, USA, p 314Google Scholar
  37. USDOE (2008) Naturita, Colorado, Processing and Disposal Sites Fact Sheet. http://www.lm.doe.gov/documents/sites/co/naturita_d/fact_sheet/naturita.pdf. Accessed 1 October 2008
  38. Vrionis HA, Anderson RT, Ortiz-Benard I, O’Neill KR, Resch CT, Peacock AD, Dayvault R, White DC, Long PE, Lovely DR (2005) Microbiological and geochemical heterogeneity in an in situ uranium bioremediation field site. Appl Environ Microbiol 71(10):6308–6318CrossRefGoogle Scholar
  39. Waite TD, Davis JA, Payne TE, Waychunas GA, Xu N (1994) Uranium(VI) adsorption to ferrihydrite: application of a surface complexation model. Geochim Cosmochim Acta 58(24):5465–5478CrossRefGoogle Scholar
  40. Zheng C, Wang PP (1999) MT3DMS, a modular three-dimensional multi-species transport model for simulation of advection, dispersion and chemical reactions of contaminants in ground water systems; documentation and user’s guide. US Army Engineer Research and Development Center Contract Report SERDP-99-1, Vicksburg, MS, USA, p 202Google Scholar
  41. Zhu C (2003) A case against Kd-based transport models: natural attenuation at a mill tailings site. Comput Geosci 29(3):351–359CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Gary P. Curtis
    • 1
  • Matthias Kohler
    • 2
  • James A. Davis
    • 1
  1. 1.US Geological SurveyMenlo ParkUSA
  2. 2.Department of Civil and Environmental EngineeringUniversity of MaineOronoUSA

Personalised recommendations