Characterizing particle‐scale equilibrium adsorption and kinetics of uranium(VI) desorption from U‐contaminated sediments

Stoliker, Deborah L.; Liu, Chongxuan; Kent, Douglas B.; Zachara, John M.

doi:10.1002/wrcr.20104

Cited by 25 publications

(55 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The equilibrium sorption/desorption of labile U(VI) in the sediment composite and all individual grain-size fractions can be effectively described using the following surface complexation reaction (Stoliker et al 2013;Sparks 1995),…”

Section: Simulation Modelsmentioning

confidence: 99%

“…The additivity model as conceptualized in Shang et al (2011), Stoliker et al (2013 and Sparks (1995) can be generally described using the following equation…”

Section: Additivity Modelmentioning

confidence: 99%

“…2 Distributed rate constants inversely estimated from U(VI) desorption in individual grain-size fractions (a <0.075 mm, b 0.075 to 0.5 mm, c 0.5 to 2 mm, d 2 to 8 mm). Solid lines with circles denote median rate constants, and dash lines indicate 95 % credible interval the grain-size based additivity model for predicting U(VI) sorption and desorption because the same set of surface complexation reactions can be used for all the grain-size fractions (Shang et al 2011;Stoliker et al 2013). However, the concept of the grainsize based model can also be used for sediments with different mineral compositions when different U(VI) surface complexation reactions may have to be used (Shang et al 2011).…”

Section: Sediment Propertiesmentioning

confidence: 99%

“…The additivity model, which uses grain-size distribution to scale reaction properties, has been proposed to address the scaling challenge (Shang et al 2011;Stoliker et al 2013;Sparks 1995). The approach assumes that the sediment reaction properties for numerical grid cells in a specific geological unit or faces can be described by linearly adding corresponding reaction properties for individual grain-size fractions that comprise the sediment.…”

Section: Introductionmentioning

confidence: 99%

“…The reaction properties determined in the laboratory for individual grain-size fractions can then be extrapolated to a field site using field-scale grain-size distribution. The approach has been demonstrated in laboratory experiments to scale U(VI) desorption involving reactions of U(VI) surface complexation, denitrification, mineral dissolution, and cation exchange Shang et al 2014;Stoliker et al 2013;Sparks 1995). However, the additivity model was, in principle, designed for extensive variables and parameters such as aqueous or sediment-associated mass of reactive species, total reactive mineral surface area, and sorption site number, etc.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Grain-Size Based Additivity Models for Scaling Multi-rate Uranyl Surface Complexation in Subsurface Sediments

Zhang

Liu

et al. 2015

Math Geosci

Self Cite

View full text Add to dashboard Cite

The additivity model assumed that field-scale reaction properties in a sediment including surface area, reactive site concentration, and reaction rate can be predicted from field-scale grain-size distribution by linearly adding reaction properties estimated in laboratory for individual grain-size fractions. This study evaluated the additivity model in scaling mass transfer-limited, multi-rate uranyl (U(VI)) surface complexation reactions in a contaminated sediment. Experimental data of rate-limited U(VI) desorption in a stirred flow-cell reactor were used to estimate the statistical properties of the rate constants for individual grain-size fractions, which were then used to predict rate-limited U(VI) desorption in the composite sediment. The result indicated that the additivity model with respect to the rate of U(VI) desorption provided a good prediction of U(VI) desorption in the composite sediment. However, the rate constants were not directly scalable using the additivity model. An approximate additivity model for directly scaling rate constants was subsequently proposed and evaluated. The result found that the approximate model provided a good prediction of the experimental results within statistical uncertainty. This study also found that a gravel-size fraction (2 to 8 mm), which is often ignored in modeling U(VI) sorption and desorption, is statistically significant to the U(VI) desorption in the sediment.

show abstract

Section: Simulation Modelsmentioning

confidence: 99%

“…The additivity model as conceptualized in Shang et al (2011), Stoliker et al (2013 and Sparks (1995) can be generally described using the following equation…”

Section: Additivity Modelmentioning

confidence: 99%

Section: Sediment Propertiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Grain-Size Based Additivity Models for Scaling Multi-rate Uranyl Surface Complexation in Subsurface Sediments

Zhang

Liu

et al. 2015

Math Geosci

Self Cite

View full text Add to dashboard Cite

show abstract

Assessment of controlling processes for field-scale uranium reactive transport under highly transient flow conditions

Chen

Liu

et al. 2014

Water Resour. Res.

Self Cite

View full text Add to dashboard Cite

This paper presents the results of a comprehensive model-based analysis of a uranyl [U(VI)]tracer test conducted at the U.S. DOE Hanford 300 Area (300A) IFRC. Despite the highly complex field conditions the numerical three-dimensional multicomponent reactive transport model was able to capture most of the spatiotemporal variations of the observed U(VI) concentrations. A multimodel analysis was performed to interrogate the relative importance of various processes and factors for controlling field-scale reactive transport during the uranyl tracer test. The results indicate that multirate sorption/desorption, surface complexation reactions, and initial concentration distributions were the most important processes and factors controlling U(VI) migration. On the other hand, cation exchange reactions, the choice of the surface complexation model, and dual-domain mass transfer processes played less important roles under the prevailing field-test conditions. Further analysis of the modeling results demonstrates that these findings are conditioned to the relatively stable groundwater chemistry and the selected length of the field experimental duration (16 days). The model analysis also revealed the crucial role of the intraborehole flow that occurred within the long-screened monitoring wells and thus affected both field measurements and simulated U(VI) concentrations as a combined effect of aquifer heterogeneity and dynamic flow conditions. This study provides the first highly data-constrained uranium transport simulations under highly dynamic flow conditions. It illustrates the value of reactive transport modeling for elucidating the relative importance of individual processes in controlling uranium transport under specific field-scale conditions.

show abstract

Long-term kinetics of uranyl desorption from sediments under advective conditions

et al. 2014

Self Cite

View full text Add to dashboard Cite

Long-term (>4 months) column experiments were performed to investigate the kinetics of uranyl (U(VI)) desorption in sediments collected from the Integrated Field Research Challenge site at the U.S. Department of Energy Hanford 300 Area. The experimental results were used to evaluate alternative multirate surface complexation reaction (MRSCR) approaches to describe the short and long-term kinetics of U(VI) desorption under flow conditions. The surface complexation reaction (SCR) stoichiometry and equilibrium constants and multirate parameters in the MRSCR models were independently characterized in batch and stirred flow-cell reactors. MRSCR models that were either additively constructed using the MRSCRs for individual size fractions, or composite in nature, could effectively describe short-term U(VI) desorption under flow conditions. The long-term desorption results, however, revealed that using the labile U concentration measured by carbonate extraction underestimated desorbable U(VI) and the longterm rate of U(VI) desorption. This study also found that the gravel size fraction (2-8 mm), which is typically treated as nonreactive in modeling U(VI) reactive transport because of low external surface area, can have an important effect on the U(VI) desorption in the sediment. This study demonstrates an approach to effectively extrapolate U(VI) desorption kinetics for field-scale application and identifies important parameters and uncertainties affecting model predictions.

show abstract

Characterizing particle‐scale equilibrium adsorption and kinetics of uranium(VI) desorption from U‐contaminated sediments

Cited by 25 publications

References 67 publications

Grain-Size Based Additivity Models for Scaling Multi-rate Uranyl Surface Complexation in Subsurface Sediments

Grain-Size Based Additivity Models for Scaling Multi-rate Uranyl Surface Complexation in Subsurface Sediments

Assessment of controlling processes for field-scale uranium reactive transport under highly transient flow conditions

Long-term kinetics of uranyl desorption from sediments under advective conditions

Contact Info

Product

Resources

About