Results 161 to 170 of about 608,534 (199)

Determination of Exchangeable Calcium of Calcareous and Gypsiferous Bentonites

Clays and Clay Minerals, 2010
AbstractThe aim of the present study was to find methodological tools to obtain reasonable results for exchangable Ca2+ of gypsiferous bentonites. Cation exchange capacity (CEC) is an important property of clays. Numerous methods for calculating CEC and exchangeable cations exist; determination of exchangeable Ca2+ fails, however, when gypsiferous ...
Dohrmann, Reiner, Kaufhold, Stephan
openaire   +3 more sources

Carbaryl Adsorption on Calcium‐Bentonite and Soils

Soil Science Society of America Journal, 1980
Abstract Adsorption of carbaryl on Ca‐bentonite, and two Egyptian soils, a Nile alluvial and a highly calcareous soil, was carried out at different temperatures. Carbaryl adsorption increased as the temperature decreases. Ca‐bentonite exhibited the highest degree of adsorption followed by the Nile alluvial soil and the calcareous soil.
M. I. Aly, N. Bakry, F. Kishk, A. H. El‐Sebae   +3 more
openaire   +1 more source

Effect of pre-treatment of bentonite with sodium and calcium ions on phosphate adsorption onto zirconium-modified bentonite

Journal of Environmental Management, 2018
To understand the influence of the pre-treatment of bentonite with Na+ and Ca2+ on the adsorption of phosphate on zirconium-modified bentonite, three kinds of adsorbent materials including zirconium-modified raw, Na+-pretreated and Ca2+-pretreated bentonites were synthesized and characterized firstly, and afterward their adsorption performance and ...
Bohui Jiang, Yanhui Zhan
exaly   +3 more sources

Sulphuric Acid Activation of a Calcium Bentonite

Particulate Science and Technology, 2004
The objective of this work was to determine the changes of thermal and surface properties of a bentonite from Cankιrι after activation using different concentrations of H2SO4 solutions (0.5–4 M). XRD, FTIR, DTA, and TG analyses of the samples were performed to examine the structural changes of the bentonite before and after acid activation.
N. YILDIZ, Z. AKTAS, A. CALIMLI
openaire   +1 more source

Calcium and Sodium Bentonite for Hydraulic Containment Applications

Journal of Geotechnical and Geoenvironmental Engineering, 1997
The hydraulic conductivity of calcium and sodium bentonites was investigated for sand-bentonite mixtures, a thin bentonite layer simulating a geosynthetic clay liner (GCL), and bentonite-cement mixtures simulating backfill for a vertical cutoff wall. The permeant liquids were tap water and distilled water containing 0.25 M calcium chloride. In general,
Mark H. Gleason, David E. Daniel, Gerald R. Eykholt   +2 more
openaire   +1 more source

Calcium-Resistant Membrane Behavior of Polymerized Bentonite

Journal of Geotechnical and Geoenvironmental Engineering, 2014
AbstractTraditional (unmodified) sodium bentonite (Na-bentonite) has been shown to exhibit semipermeable membrane behavior, which is beneficial in terms of the use of Na-bentonites as barriers or components of barriers for hydraulic containment applications.
Gretchen L. Bohnhoff, Charles D. Shackelford, Kristin M. Sample-Lord   +2 more
openaire   +1 more source

The Role of Calcium-Based Additives in Bentonite Stabilization: A Comparative Evaluation

Arabian Journal for Science and Engineering
Waste recycling plays a critical role in addressing environmental challenges by conserving natural resources, reducing pollution, and mitigating the environmental impact of human activities.
Eris Uygar, Bashar Alibrahim
exaly   +2 more sources

Properties of Water in Calcium- and Hexadecyltrimethylammonium-Exchanged Bentonite

Clays and Clay Minerals, 1999
AbstractDynamical and thermodynamic properties of water at room temperature in Ca- and hexade-cyltrimethylammonium- (HDTMA) exchanged bentonite were determined for 4 different water contents (~0.03–0.55 g water g-1 clay). Incoherent quasi-elastic neutron scattering (QENS) was used to measure the translational and rotational mobility of water in the ...
Michael A. Anderson, Frans R. Trouw, Cheok N. Tam   +2 more
openaire   +1 more source

Interaction between Calcium Carbonates and Bentonite Suspensions

Nature, 1963
CALCIUM carbonate in soil is generally assumed to behave like pure calcite. Equations relating calcium carbonate solubility to carbon dioxide pressure have been given, though their application to calcareous soils has not yet been tested thoroughly1,2. Thus, usually only the system CaCO3–CO2–H2O is considered, neglecting a possible interaction between ...
N. LAHAV, G. H. BOLT
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Forces Between Suspended Bentonite Particles Part II—Calcium Bentonite

Clays and clay minerals (National Conference on Clays and Clay Minerals), 1957
AbstractIn a previous paper (van Olphen, 1956) data were presented for the rheological and sedimentation behavior of sodium bentonite suspensions in water. From these data particle interaction energies were derived. Analogous data have been collected for calcium bentonite suspensions.
openaire   +1 more source