Hydraulic and physicochemical properties of dense thin bentonite layers permeated with variably mixed alkaline solutions of KOH and CaCl2 at various temperatures (25-75 degrees C) for 3 years
- Authors
- Yoon, Yeowon; Anh, Ha Ngoc; Rha, Sunwon; Kim, Jin-Seok; Jo, Ho Young
- Issue Date
- 6월-2022
- Publisher
- ELSEVIER SCI LTD
- Keywords
- Bentonite barrier; Alkaline solution; Hydraulic conductivity; Cation exchange; Coupled thermal -hydraulic -chemical process
- Citation
- GEOTEXTILES AND GEOMEMBRANES, v.50, no.3, pp.521 - 534
- Indexed
- SCIE
SCOPUS
- Journal Title
- GEOTEXTILES AND GEOMEMBRANES
- Volume
- 50
- Number
- 3
- Start Page
- 521
- End Page
- 534
- URI
- https://scholar.korea.ac.kr/handle/2021.sw.korea/140656
- DOI
- 10.1016/j.geotexmem.2022.02.004
- ISSN
- 0266-1144
- Abstract
- Hydraulic conductivity tests were performed using mixed alkaline solutions of KOH and CaCl2 (pH ~12) on thin Na-bentonite layers under various temperature conditions (25-75 & DEG;C) for 3 years. For dense thin Na-bentonite (dry density of 1.12 Mg/m(3)) in a mixed alkaline solution of 0.03 M KOH and 0.03 M CaCl2, the hydraulic conductivities at 50 & DEG;C and 75 & DEG;C were approximately 10 times higher than that at 25 & DEG;C. The bentonite samples permeated with the mixed solution at 50 & DEG;C and 75 & DEG;C achieved almost complete cation exchange of Na ions by Ca and K ions. However, only slight cation exchange occurred in the bentonite specimens permeated at 25 & DEG;C, regardless of the type of permeant. The free swell index of the reacted bentonite permeated with a mixed solution of 0.03 M KOH and 0.03 M CaCl2 significantly decreased at 50 & DEG;C and 75 & DEG;C compared with that at 25 & DEG;C. X-ray diffraction analysis revealed that the decreases in the relative intensities of the peaks of accessory minerals, such as opal-cristobalite/tridymite, quartz, and feldspar, were enhanced at 50 & DEG;C and 75 & DEG;C.
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Collections - College of Science > Department of Earth and Environmental Sciences > 1. Journal Articles
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