Mechanism of Kaolinite Dissolution at Room Temperature and Pressure: Part 1. Surface Speciation

Huertas, F. Javier; Chou, Lei; Wollast, Roland

doi:10.1016/s0016-7037(97)00366-9

Cited by 163 publications

(126 citation statements)

References 48 publications

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“…We compare our strontium sorption results to the net kaolinite surface charge determined by potentiometric titration in a CO 2 -free environment on kaolinite from the same source (KGa-1), at the same ionic strength, and over the same pH range as in our experiments (52). At pH greater than 5.5, the kaolinite surface charge becomes increasingly more negative, which reflects an increase in the number of negatively charged surface sites.…”

Section: Strontium Complexes At Kaolinite and Amorphous Silica Surfacesmentioning

confidence: 83%

X-Ray Absorption Spectroscopy of Strontium(II) Coordination

Sahai

Carroll

Roberts

et al. 2000

Journal of Colloid and Interface Science

139

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Section: Strontium Complexes At Kaolinite and Amorphous Silica Surfacesmentioning

confidence: 83%

X-Ray Absorption Spectroscopy of Strontium(II) Coordination

Sahai

Carroll

Roberts

et al. 2000

Journal of Colloid and Interface Science

139

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“…Experimental data for the constants K and M AX can be obtained by performing an optimization procedure between our model and the titration experiments reported by Huertas (Huertas et al 1997). This yields K = 10 5.5 l/mol and M AX = 3.0 sites/nm 2 (Lima et al 2008).…”

Section: -Pk Modelmentioning

confidence: 93%

“…As the surface charge and the ζ -potential vary strongly with the p H of the electrolyte solution, the closure of the system is tied-up to the construction of this dependence that can be accomplished by invoking the kinetics of the protonation/deprotonation reactions presented next (Chorover and Sposito 1995, Ganor et al 2003, Huertas et al 1997). …”

mentioning

confidence: 99%

Electro-osmosis in kaolinite with pH-dependent surface charge modelling by homogenization

Lima¹,

Murad

Moyne³

et al. 2010

An. Acad. Bras. Ciênc.

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A new three-scale model to describe the coupling between p H -dependent flows and transient ion transport, including adsorption phenomena in kaolinite clays, is proposed. The kaolinite is characterized by three separate nano/micro and macroscopic length scales. The pore (micro)-scale is characterized by micro-pores saturated by an aqueous solution containing four monovalent ions and charged solid particles surrounded by thin electrical double layers. The movement of the ions is governed by the Nernst-Planck equations, and the influence of the double layers upon the flow is dictated by the Helmholtz-Smoluchowski slip boundary condition on the tangential velocity. In addition, an adsorption interface condition for the N a + transport is postulated to capture its retention in the electrical double layer. The two-scale nano/micro model including salt adsorption and slip boundary condition is homogenized to the Darcy scale and leads to the derivation of macroscopic governing equations. One of the notable features of the three-scale model is the reconstruction of the constitutive law of effective partition coefficient that governs the sodium adsorption in the double layer. To illustrate the feasibility of the three-scale model in simulating soil decontamination by electrokinetics, the macroscopic model is discretized by the finite volume method and the desalination of a kaolinite sample by electrokinetics is simulated.

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“…In addition to the ionic concentrations in the electrical double layer (EDL), sorption phenomena owing to protonation/deprotonation reactions involving the H + ions also take place at particle surface. Such chemical reactions have a paramount influence on the magnitude of the surface charge density and the zeta potential and must be incorporated in the nanoscopic description (Avena and De Pauli 1996;Huertas et al 1997;Schroth and Sposito 1997). The equilibrium nature of chemical reactions along with the fast characteristic time-scale of the electro-chemical processes taking place in the EDL compared to the one associated with the hydrodynamics in the bulk fluid in the micropores suggest adopting the local equilibrium hypothesis at the nanoscale.…”

Section: Nanoscale Modeling For Sorptionmentioning

confidence: 99%

A Three-Scale Model of pH-Dependent Flows and Ion Transport with Equilibrium Adsorption in Kaolinite Clays: I. Homogenization Analysis

et al. 2010

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A new three-scale model to describe the coupling between pH-dependent flows and transient ion transport including sorption phenomena in kaolinite clays is proposed. The kaolinite is characterized by three separate nano-micro and macroscopic length scales. The (micro)-scale consists of micro-pores saturated by an aqueous solution containing four monovalent ionic species (Na + , H + , Cl − , OH − ) and charged solid particles surrounded by thin electrical double layers. The movement of the ions is governed by the Nernst-Planck equations and the influence of the double layers upon the flow is dictated by the Helmholtz-Smoluchowski slip boundary condition in the tangential velocity. In addition, sorption interface conditions for ion transport are postulated in the sense of Auriault and Lewandowska (Eur. J. Mech. A 15: 1996) to capture the immobilization of the ions in the electrical double layer and on particle surface due to protonation/deprotonation reactions. The intensity of sorption relative to diffusion effects is quantified by the Damköhler number, whose order of magnitude is estimated by invoking the nanoscopic modeling of the thin EDL based on Poisson-Boltzmann problem for the local electric potential coupled with a non-linear surface charge density with constitutive law dictated by the protonation/deprotonation reactions. The two-scale nano/micro model including sorption and slip boundary condition is homogenized to the core scale leading to a derivation of macroscopic governing equations.

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Mechanism of Kaolinite Dissolution at Room Temperature and Pressure: Part 1. Surface Speciation

Cited by 163 publications

References 48 publications

X-Ray Absorption Spectroscopy of Strontium(II) Coordination

X-Ray Absorption Spectroscopy of Strontium(II) Coordination

Electro-osmosis in kaolinite with pH-dependent surface charge modelling by homogenization

A Three-Scale Model of pH-Dependent Flows and Ion Transport with Equilibrium Adsorption in Kaolinite Clays: I. Homogenization Analysis

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