Rate-limited cation exchange in thin bentonitic barrier layers

Ho Young Jo, Craig H. Benson, Tuncer B. Edil

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

A three-compartment model was developed for simulating cation transport in bentonitic barrier layers that incorporates diffusion-controlled cation exchange among the mobile intergranular water (bulk pore water), immobile interparticle and interlayer water, and the montmorillonite mineral solid. Exchange on the external surfaces and interlayer region of montmorillonite is included. The model was evaluated for divalent-for-monovalent cation exchange in bentonite with experiments. A parametric study was conducted using the model to investigate factors affecting the time required to establish chemical equilibrium (i.e., completion of cation exchange) between the permeant liquid and thin layers of bentonite simulating geosynthetic clay liners (GCLs). Predictions obtained with the model were in general agreement with the data without calibration, except for Na concentrations in the effluent at very long times. Parametric simulations conducted with the model show that the time required to establish chemical equilibrium in GCLs is affected by the rate at which adsorbing cations are delivered to the pore space (affected by seepage velocity or influent concentration), the rate of mass transfer between the mobile and immobile liquid phases (controlled primarily by granule size of the bentonite), and the number of sites available for sorption (controlled by CEC and the dry density of the bentonite).

Original languageEnglish
Pages (from-to)370-391
Number of pages22
JournalCanadian Geotechnical Journal
Volume43
Issue number4
DOIs
Publication statusPublished - 2006 Apr 1

Fingerprint

Bentonite
ion exchange
Ion exchange
bentonite
Positive ions
clay liner
geosynthetics
Clay minerals
montmorillonite
Clay
cation
Water
liquid
dry density
Liquids
Seepage
pore space
cation exchange capacity
seepage
Sorption

Keywords

  • Bentonite
  • Diffusion
  • Exchange complex
  • Immobile liquid
  • Interlayer
  • Montmorillonite

ASJC Scopus subject areas

  • Geotechnical Engineering and Engineering Geology

Cite this

Rate-limited cation exchange in thin bentonitic barrier layers. / Jo, Ho Young; Benson, Craig H.; Edil, Tuncer B.

In: Canadian Geotechnical Journal, Vol. 43, No. 4, 01.04.2006, p. 370-391.

Research output: Contribution to journalArticle

Jo, Ho Young ; Benson, Craig H. ; Edil, Tuncer B. / Rate-limited cation exchange in thin bentonitic barrier layers. In: Canadian Geotechnical Journal. 2006 ; Vol. 43, No. 4. pp. 370-391.
@article{bb5eccefb4fc49b19a5361a6d8a090a9,
title = "Rate-limited cation exchange in thin bentonitic barrier layers",
abstract = "A three-compartment model was developed for simulating cation transport in bentonitic barrier layers that incorporates diffusion-controlled cation exchange among the mobile intergranular water (bulk pore water), immobile interparticle and interlayer water, and the montmorillonite mineral solid. Exchange on the external surfaces and interlayer region of montmorillonite is included. The model was evaluated for divalent-for-monovalent cation exchange in bentonite with experiments. A parametric study was conducted using the model to investigate factors affecting the time required to establish chemical equilibrium (i.e., completion of cation exchange) between the permeant liquid and thin layers of bentonite simulating geosynthetic clay liners (GCLs). Predictions obtained with the model were in general agreement with the data without calibration, except for Na concentrations in the effluent at very long times. Parametric simulations conducted with the model show that the time required to establish chemical equilibrium in GCLs is affected by the rate at which adsorbing cations are delivered to the pore space (affected by seepage velocity or influent concentration), the rate of mass transfer between the mobile and immobile liquid phases (controlled primarily by granule size of the bentonite), and the number of sites available for sorption (controlled by CEC and the dry density of the bentonite).",
keywords = "Bentonite, Diffusion, Exchange complex, Immobile liquid, Interlayer, Montmorillonite",
author = "Jo, {Ho Young} and Benson, {Craig H.} and Edil, {Tuncer B.}",
year = "2006",
month = "4",
day = "1",
doi = "10.1139/t06-014",
language = "English",
volume = "43",
pages = "370--391",
journal = "Canadian Geotechnical Journal",
issn = "0008-3674",
publisher = "National Research Council of Canada",
number = "4",

}

TY - JOUR

T1 - Rate-limited cation exchange in thin bentonitic barrier layers

AU - Jo, Ho Young

AU - Benson, Craig H.

AU - Edil, Tuncer B.

PY - 2006/4/1

Y1 - 2006/4/1

N2 - A three-compartment model was developed for simulating cation transport in bentonitic barrier layers that incorporates diffusion-controlled cation exchange among the mobile intergranular water (bulk pore water), immobile interparticle and interlayer water, and the montmorillonite mineral solid. Exchange on the external surfaces and interlayer region of montmorillonite is included. The model was evaluated for divalent-for-monovalent cation exchange in bentonite with experiments. A parametric study was conducted using the model to investigate factors affecting the time required to establish chemical equilibrium (i.e., completion of cation exchange) between the permeant liquid and thin layers of bentonite simulating geosynthetic clay liners (GCLs). Predictions obtained with the model were in general agreement with the data without calibration, except for Na concentrations in the effluent at very long times. Parametric simulations conducted with the model show that the time required to establish chemical equilibrium in GCLs is affected by the rate at which adsorbing cations are delivered to the pore space (affected by seepage velocity or influent concentration), the rate of mass transfer between the mobile and immobile liquid phases (controlled primarily by granule size of the bentonite), and the number of sites available for sorption (controlled by CEC and the dry density of the bentonite).

AB - A three-compartment model was developed for simulating cation transport in bentonitic barrier layers that incorporates diffusion-controlled cation exchange among the mobile intergranular water (bulk pore water), immobile interparticle and interlayer water, and the montmorillonite mineral solid. Exchange on the external surfaces and interlayer region of montmorillonite is included. The model was evaluated for divalent-for-monovalent cation exchange in bentonite with experiments. A parametric study was conducted using the model to investigate factors affecting the time required to establish chemical equilibrium (i.e., completion of cation exchange) between the permeant liquid and thin layers of bentonite simulating geosynthetic clay liners (GCLs). Predictions obtained with the model were in general agreement with the data without calibration, except for Na concentrations in the effluent at very long times. Parametric simulations conducted with the model show that the time required to establish chemical equilibrium in GCLs is affected by the rate at which adsorbing cations are delivered to the pore space (affected by seepage velocity or influent concentration), the rate of mass transfer between the mobile and immobile liquid phases (controlled primarily by granule size of the bentonite), and the number of sites available for sorption (controlled by CEC and the dry density of the bentonite).

KW - Bentonite

KW - Diffusion

KW - Exchange complex

KW - Immobile liquid

KW - Interlayer

KW - Montmorillonite

UR - http://www.scopus.com/inward/record.url?scp=33744526377&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33744526377&partnerID=8YFLogxK

U2 - 10.1139/t06-014

DO - 10.1139/t06-014

M3 - Article

VL - 43

SP - 370

EP - 391

JO - Canadian Geotechnical Journal

JF - Canadian Geotechnical Journal

SN - 0008-3674

IS - 4

ER -