Article
Geochemistry & Geophysics
Paul Wersin, Martin Mazurek, Thomas Gimmi
Summary: This study evaluates the porewater chemistry data obtained from different extraction methods in clayrocks and finds that the composition of porewater varies and is constrained by diffusive exchange, carbonate mineral and celestite equilibria.
APPLIED GEOCHEMISTRY
(2022)
Article
Geochemistry & Geophysics
Philipp Krejci, Thomas Gimmi, Luc Robert Van Loon
Summary: Cation diffusion coefficients in clayey materials may be higher than water tracers, especially for cations strongly adsorbed on clay surfaces. The study highlights the challenges in applying Fick's law to cation diffusion in clays and emphasizes the need for a consistent description for predicting experiments under different conditions.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Engineering, Ocean
Jie Yin, Zhijun Lu, Weijuan Geng, Wenxia Han, Abdulmalik A. Hudu
Summary: The compression index decreases with increasing porewater salinity for soft marine clay, and hydraulic conductivity increases with increasing salinity, dominated by inter-aggregated voids. The influence of porewater salinity on soil behaviors is limited at high salinity levels.
MARINE GEORESOURCES & GEOTECHNOLOGY
(2022)
Review
Engineering, Geological
Yara Barakat, Nadia Mokni, Yu-Jun Cui, Pierre Delage, Frederic Bernier
Summary: Three small-scale mock-up tests were conducted on Opalinus Clay samples to investigate the self-sealing behavior of fractures. The tests showed that synthetic water and alkaline solution may hinder the self-sealing process, while saline solutions can increase permeability and accelerate hydration but cannot completely seal the fractures.
CANADIAN GEOTECHNICAL JOURNAL
(2023)
Article
Green & Sustainable Science & Technology
Muawia Dafalla
Summary: This study investigated the effects of saline water, specific chemicals, cement, and bentonite on sand-clay liners. It was found that adding bentonite grout improved hydraulic conductivity, while cement had a significant effect on compressibility. These findings can guide the design and assessment of sand-clay liners in semi-arid regions and coastal zones.
Article
Computer Science, Interdisciplinary Applications
Jesus F. Aguila, Vanessa Montoya, Javier Samper, Luis Montenegro, Georg Kosakowski, Wilfried Pfingsten, Philipp Kre
Summary: This study focuses on the migration of moderately sorbing radionuclide cesium in Opalinus clay, using various models and codes for benchmarking. The results show that both single-species and multi-species concepts can achieve good agreement, with some discrepancies near the boundaries.
COMPUTATIONAL GEOSCIENCES
(2021)
Article
Environmental Sciences
Yijie Wang, Liming Hu, Shengmin Luo, Ning Lu
Summary: This study investigates the relationship between soil-water retention curve (SWRC) and soil-water isotherm (SWI) and proposes a closed-form SWI model that can accurately fit adsorption and desorption isotherms for different types of soils. The proposed model demonstrates the ability to distinguish between different soil-water retention processes and has been experimentally validated for its wide applicability and effectiveness.
VADOSE ZONE JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Min Wang, Jiaming Wen, Heng Zhuang, Weiyi Xia, Ningjun Jiang, Yanjun Du
Summary: This article introduces a dual-additives-amended compacted clay cover system, which can enhance the performance of clay in terms of crack resistance, moisture retention, gas barrier, and hydraulic performance. The use of attapulgite and diatomite as dual additives improves the moisture retention and liquid limit of the clay, as well as significantly reduces the gas diffusion coefficient. The dual-additives-amended clay shows better performance in terms of liquid limit, moisture retention, gas barrier, and hydraulic performance compared to unamended clay.
APPLIED SCIENCES-BASEL
(2022)
Article
Multidisciplinary Sciences
Partha Das, Tadikonda Venkata Bharat
Summary: The study demonstrates that compacted granular bentonite (GB) exhibits significant mechanical collapse under high ionic strength salt solutions, raising concerns about its applicability in landfill liner facilities. Introducing kaolin as an additional barrier can effectively improve sealing and swelling abilities, making the kaolin-GB layered system suitable for landfill liners even in adverse saline conditions and low overburden stresses.
SCIENTIFIC REPORTS
(2021)
Article
Engineering, Environmental
C. M. Aswathy, B. M. Sunil
Summary: This study evaluated the effect of inorganic contaminants on the behavior of bentonite-based landfill liner material at different blending ratios. Results showed a decrease in hydraulic conductivity, a slight reduction in unconfined compressive strength under wet conditions, and good adsorption characteristics of the blended lithomargic clay with bentonite.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2022)
Article
Engineering, Environmental
Mehmet Sukru Ozcoban, Seren Acarer, Nese Tufekci
Summary: This article examined the change in hydraulic conductivity of landfill liners caused by contaminants in leachate and the mechanisms responsible for this change. It identified deficiencies in the literature on this topic and presented directions for future studies.
WATER SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Geological
D. A. Dixon, J. Stone, K. Birch, C. S. Kim
Summary: Several countries plan to safely store used nuclear fuel underground in deep geologic repositories. Canada's NWMO suggests using corrosion-resistant containers and bentonite-based sealing systems to ensure low hydraulic conductivity and swelling ability when in contact with groundwater. Data from studies on bentonite behavior are evaluated to determine the best-fit relationships between density, swelling pressure, and hydraulic conductivity under different pore fluid conditions.
CANADIAN GEOTECHNICAL JOURNAL
(2023)
Article
Engineering, Geological
D. A. Dixon, J. Stone, K. Birch, C. S. Kim
Summary: Several countries, including Canada's NWMO, are planning to safely isolate used nuclear fuel deep underground. The sealing systems, using bentonite-based materials, need to have low hydraulic conductivity and the ability to swell when in contact with groundwater. Data and ongoing studies show the relationship between dry density, swelling pressure, and hydraulic conductivity under different porefluid compositions.
CANADIAN GEOTECHNICAL JOURNAL
(2023)
Article
Geochemistry & Geophysics
Nele Bleyen, Joe S. Small, Kristel Mijnendonckx, Katrien Hendrix, Achim Albrecht, Pierre De Canniere, Maryna Surkova, Charles Wittebroodt, Elie Valcke
Summary: The study shows that microbial activity is essential for transforming Se(VI) into more reduced and sorbing species in Opalinus Clay, while Se(VI) remains unreactive under abiotic conditions. In addition, Se(IV) can be reduced by microorganisms or sorb in the presence of clay without microorganisms.
Article
Engineering, Geological
Yong-Min Kim, Tae-Hyuk Kwon
Summary: The use of bacterial biofilms and EPS for engineered bioclogging in geotechnical practices has gained attention, with the addition of fine clay particles enhancing the durability of biofilm-induced bioclogging. Experiments showed that biofilm associated with bentonite particles demonstrated improved resistance against fluid flows compared to biofilms alone, suggesting the potential of bentonite-biofilm aggregations in enhancing bioclogging durability in nutrient-poor conditions.