Low-head hyperfiltration through Jurassic-Cretaceous metamorphic Darrington Phyllite discs (from the Northwest Cascades of Washington State, USA)

Hart, Megan

doi:10.1007/s10040-012-0905-8

Cited by 5 publications

(4 citation statements)

References 31 publications

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“…The key parameter of interest with respect to semipermeable membrane behavior is the membrane efficiency or reflection coefficient, ω, which typically ranges from zero for no solute restriction to unity for complete solute restriction (0 ≤ ω ≤ 1.0), although slightly negative values of ω are also possible. Column tests that are conducted to measure ω are commonly referred to as hyperfiltration or ultrafiltration tests (e.g., Fritz, 1986;Hart, 2013). In these tests, the source solution is forced through the soil under an applied hydraulic head, and if the soil behaves as a semipermeable membrane, the solute is filtered out such that only a fraction of the source concentration appears in the effluent (see Fig.…”

Section: Semipermeable Membrane Behaviormentioning

confidence: 99%

Fundamental considerations for column testing of engineered, clay-based barriers

Shackelford

2021

JGS Special Publication

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The purpose of column testing is to determine the transport and fate properties, typically the hydrodynamic dispersion coefficient (Dh) and retardation factor (Rd), of aqueous miscible chemical species (solutes) with respect to a given porous medium. This paper presents fundamental considerations required for column testing of engineered, lowpermeability, clay-based barriers, such as compacted clay liners, geosynthetic clay liners, and soil-bentonite vertical cutoff walls, used to contain chemicals in a variety of solid and liquid waste containment and remediation applications. The presentation is limited to column tests conducted with a constant solute source concentration, and includes descriptions of the general procedures for conducting column tests as well as the expected behavior of the solute (effluent) breakthrough curve (BTC) based on several considerations. Significant information can be gained simply from the shape of the solute BTC. For example, a sigmoidal symmetric BTC implies advective-dominated solute transport with linear, instantaneous, and reversible sorption, whereas a sigmoidal asymmetric BTC can result from diffusion-dominated transport, nonlinear sorption, and/or nonequilibrium (kinetic) sorption. Also, because clay-based barriers are susceptible to hydraulic incompatibility when permeated with chemical solutions, significant hydraulic incompatibility can lead to a significant change in the seepage velocity (vs) under the constant hydraulic head (gradient) condition, which invalidates the use of analytical transport models to determine Dh and Rd via fitting of the measured solute BTCs, as well as the use of dimensionless time or pore volumes of flow. For this reason, constant flow hydraulic control is recommended for conducting column tests with engineered, low-permeability, clay-based barriers, because significant changes in hydraulic conductivity do not significantly affect vs. Finally, the potential significance of diffusion on solute transport through clay-based barriers can complicate interpretation of the existence of an effective porosity and determination of the correct, mass-based definition of Rd from the BTCs emanating from traditional concentration-based column tests. However, these issues are readily discerned when cumulative mass column testing is performed. Example results from both traditional, concentration-based column testing and alternative, cumulative mass column testing of clay-based barriers are provided to illustrate application of the concepts presented.

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Section: Semipermeable Membrane Behaviormentioning

confidence: 99%

Fundamental considerations for column testing of engineered, clay-based barriers

Shackelford

2021

JGS Special Publication

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“…The approach for dealing with rocks where osmosis has not yet been measured, but could potentially occur following Alexander (1990), Neuzil and Provost (2009) and Hart (2012), can focus on effects eventually revealing its presence. It could thus be possible to consider ω 0 and Θ as very small quantities, but still allowing our theory to be applied.…”

Section: A "Theoretical Experiment" About Osmosis In Sandstonesmentioning

confidence: 99%

“…Recent research on geologic porous media has revealed how semi-permeable membranes can create chemical gradients related to osmosis (Marine and Fritz, 1981;Alexander, 1990;House and Pritchett, 1995;Nunn, 1997;Neuzil, 2000;Neuzil and Provost, 2009;Hart, 2012). This process occurs not only in low permeability rocks (e.g., clay, shale and so on), but also in limestone, dolomite and low permeability concrete.…”

Section: Introductionmentioning

confidence: 99%

On the Theory of Solitons of Fluid Pressure and Solute Density in Geologic Porous Media, with Applications to Shale, Clay and Sandstone

Caserta

Kanivetsky

Salusti

2017

Pure Appl. Geophys.

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Abstract-We here analyze a new model of transients of pore pressure p and solute density q in geologic porous media. This model is rooted in the nonlinear wave theory, its focus is on advection and effect of large pressure jumps on strain. It takes into account nonlinear and also time-dependent versions of the Hooke law about stress, rate and strain. The model solutions strictly relate p and q evolving under the effect of a strong external stress. As a result, the presence of quick and sharp transients in low permeability rocks is unveiled, i.e., the nonlinear ''Burgers solitons''. We, therefore, show that the actual transport process in porous rocks for large signals is not only the linear diffusion, but also a solitons presence could control the process. A test of a presence of solitons is applied to Pierre shale, Bearpaw shale, Boom clay and OznamMugu silt and clay. An application about the presence of solitons for nuclear waste disposal and salt water intrusions is also discussed. Finally, in a kind of ''theoretical experiment'' we show that solitons could also be present in higher permeability rocks (Jordan and St. Peter sandstones), thus supporting the idea of a possible occurrence of osmosis also in sandstones.

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“…We were more concerned about the effect on clay membrane performance in the reverse osmosis process often called hyperfiltration, which occurs when a solute is partially rejected from a solution passing through a membrane. Within an aquitard, reverse osmosis can occur when the hydraulic head pressure exceeds the osmotic pressure across the membrane (Cey et al, 2001; Graf, 1982; Hart, 2013; Oduor, 2004; Whitworth & DeRosa, 1997). Meanwhile, in the field of hydrogeology, many scholars began to study the semipermeable membrane, which proved that the aquitard has a certain semipermeable membrane effect, but there is no exact conclusion on how the properties of semipermeable membrane affect the salt permeability and isotope fractionation (Bader & Kooi, 2005; Cheng & Hendry, 2014; Elrick et al, 1976; Kocherginsky & Stucki, 2001; Neuzil, 2000; Rebeix et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Effects of ultrafiltration on salt migration and isotopic composition of pore water in groundwater depression area in Hengshui, NCP

Wang

Chen

et al. 2021

Hydrological Processes

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Clay aquitards are semipermeable membranes that allow groundwater flow while retarding solute migration has been researched extensively but also subjected to much debate. At present, there is no evidence of whether the physical and chemical properties of clay soil and the isotopic composition of pore water affect the semipermeable membrane effect. In this study, we collected clay samples from drilling cores (30-90 m) in the Hengshui area located in the North China Plain (NCP), then extracted pore water using a high-pressure squeezing device. Vertical hydrochemical and isotopic profile variation trends for the pore water were revealed using hydrochemical (Cl À , Na + , Ca 2+ , K + , Mg 2+ , and SO 4 2À ) and stable isotopic measurements of H, O and Cl. The results showed that the hydrochemical clay interlayer pore water of the saline aquifer is Cl/SO 4 -Na/Mg type and the average total dissolved solids (TDS) are 10.17 g/L. However, the hydrochemical clay aquitard pore water is

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Low-head hyperfiltration through Jurassic-Cretaceous metamorphic Darrington Phyllite discs (from the Northwest Cascades of Washington State, USA)

Cited by 5 publications

References 31 publications

Fundamental considerations for column testing of engineered, clay-based barriers

Fundamental considerations for column testing of engineered, clay-based barriers

On the Theory of Solitons of Fluid Pressure and Solute Density in Geologic Porous Media, with Applications to Shale, Clay and Sandstone

Effects of ultrafiltration on salt migration and isotopic composition of pore water in groundwater depression area in Hengshui, NCP

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