Comparative study of tracer diffusion of HTO, 22Na+ and 36Cl− in compacted kaolinite, illite and montmorillonite

Glaus, Martin A.; Frick, Sabrina; Rossé, Roger; Loon, Luc R. Van

doi:10.1016/j.gca.2010.01.010

Cited by 121 publications

(112 citation statements)

References 47 publications

(59 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is in agreement with laboratory studies on montmorillonite, bentonite and other clay-rich rocks (e.g. Glaus et al 2010;Gimmi and Kosakowski 2011;Tachi et al 2011;Tachi and Yotsuji 2014). The comparably large values may be explained by the so-called surface diffusion of sorbed cations (including cations in the diffuse layer and in interlayers), which leads to an additional driving force for diffusion besides the pore-water gradient (e.g.…”

Section: Cation Diffusion Coefficientssupporting

confidence: 91%

Exploring diffusion and sorption processes at the Mont Terri rock laboratory (Switzerland): lessons learned from 20 years of field research

Leupin

Loon

Gimmi

et al. 2017

Mont Terri Rock Laboratory, 20 Years

View full text Add to dashboard Cite

Transport and retardation parameters of radionuclides, which are needed to perform a safety analysis for a deep geological repository for radioactive waste in a compacted claystone such as Opalinus Clay, must be based on a detailed understanding of the mobility of nuclides at different spatial scales (laboratory, field, geological unit). Thanks to steadily improving experimental designs, similar tracer compositions in different experiments and complementary small laboratory-scale diffusion tests, a unique and large database could be compiled. This paper presents the main findings of 20 years of diffusion and retention experiments at the Mont Terri rock laboratory and their impact on safety analysis.

show abstract

Section: Cation Diffusion Coefficientssupporting

confidence: 91%

Exploring diffusion and sorption processes at the Mont Terri rock laboratory (Switzerland): lessons learned from 20 years of field research

Leupin

Loon

Gimmi

et al. 2017

Mont Terri Rock Laboratory, 20 Years

View full text Add to dashboard Cite

show abstract

“…In clay media, solute transport is governed primarily by molecular diffusion (Altmann et al, 2012). Experiments have shown repeatedly that anion diffusion in clay media can be described macroscopically by applying a Fickian diffusion model in a fraction of the pore space, the "anion accessible porosity" (Glaus et al, 2010). This finding is consistent with the well known 'anion exclusion' phenomenon, whereby anions are repelled electrostatically from the vicinity of negatively charged clay-mineral surfaces.…”

Section: Introductionsupporting

confidence: 62%

Impact of microstructure on anion exclusion in compacted clay media

Tournassat¹,

Gaboreau²,

Robinet³

et al. 2016

Filling the Gaps - From Microscopic Pore Structures to Transport Properties In Shales

View full text Add to dashboard Cite

The sensitivity of ion-concentration distribution models to three key model assumptions, the pore-size distribution of clay media, the 'distance of closest approach' of ions to the clay surface, and the accessibility of sub-nanometer-wide clay mineral interlayer spaces to anions, was explored by solving the Poisson-Boltzmann equation for swelling and nonswelling clay materials. The calculations show that all three model assumptions impact significantly on values predicted for the anion-accessible porosity. As a consequence, macroscopic measurements of anion exclusion in clay media cannot be used to test any of the three model assumptions independently of the other two. Information gained at the nanoscale, a detailed characterization of pore-size distribution in particular, is necessary to develop accurate predictive models of the anion accessible porosity of clay media.

show abstract

“…Glaus et al 22) applied this model to the diffusion of Cl À through Na-montmorillonite. The diffusionaccessible porosity for Cl À , which is a key parameter in this model, is empirically determined.…”

Section: Introductionmentioning

confidence: 99%

Experimental and Modeling Study on Diffusion of Selenium under Variable Bentonite Content and Porewater Salinity

Iida

Yamaguchi

Tanaka

2011

Journal of Nuclear Science and Technology

View full text Add to dashboard Cite

Effective diffusion coefficients of selenium through bentonite/sand mixtures were obtained by the through-diffusion method under reducing conditions where selenium was dissolved as HSe À and Se 4 2À . Experiments were carried out under variable bentonite content and porewater salinity. Bentonite contents in bentonite/sand mixtures varied from 20 to 70 wt%. The salinities of experimental solutions varied from 0.05 to 0.5 mol dm À3 , simulating brackish groundwater and seawater. Effective diffusion coefficients were also obtained under anaerobic conditions where the dominant selenium species was determined to be SeO 3 2À . The effective diffusion coefficients of selenium species decreased with increasing bentonite content and with decreasing salinity. This tendency is primarily due to anion exclusion that was caused by the negative surface charge of montmorillonite. A diffusion model for anionic species was developed based on the electric double layer theory and the pore diffusion model, to evaluate the diffusion behaviors of HSe À , Se 4 2À , and SeO 3 2À in bentonite porewater. In this model, pores in bentonite/sand mixtures are assumed to consist of two types of space; one is the space between mineral particles and the other is the space between layers of montmorillonite. The scope of application of this model is limited to less than or equal to 1,600 kg m À3 in dry density. The effective diffusion coefficients of selenium species predicted using this model showed good agreement with experimentally measured ones.

show abstract

Comparative study of tracer diffusion of HTO, 22Na+ and 36Cl− in compacted kaolinite, illite and montmorillonite

Cited by 121 publications

References 47 publications

Exploring diffusion and sorption processes at the Mont Terri rock laboratory (Switzerland): lessons learned from 20 years of field research

Exploring diffusion and sorption processes at the Mont Terri rock laboratory (Switzerland): lessons learned from 20 years of field research

Impact of microstructure on anion exclusion in compacted clay media

Experimental and Modeling Study on Diffusion of Selenium under Variable Bentonite Content and Porewater Salinity

Contact Info

Product

Resources

About