Abstraet---Ethylenediamine (EDA) is adsorbed from aqueous solution on Na-, Kand Li-montmorillonite as the monoprotonated cation (EDAH +) through an ion-exchange process. On washing with distilled water the second amine function is protonated--probably through dissocmtion of water near the clay surface--and simultaneously formed alkali hydroxide is removed. In air-dried clay films, prepared from...

Synthetic Aperture Radar (SAR) Interferometry (InSAR), using data from the European Space Agency satellites ERS1 and ERS2, is being used to image, survey and map surface movement of the London region. Local and regional movement due to shrink and swell of the London Clay geology, tunnelling, and possibly ground water abstraction has been investigated here for the first time by InSAR. Cyclic ann...

19 Clay-polymer composites were designed for use in filtration processes for disinfection 20 during the course of water purification. The composites were formed by sorption of 21 polymers based on starch modified with quaternary ammonium ethers onto the 22 negatively charged clay mineral bentonite. The performance of the clay-polymer 23 complexes in removal of bacteria was strongly dependent on...

Introduction: The Mars Express OMEGA imaging spectrometer recently identified clay minerals (nontronite and montmorillonite) in several outcrops of Noachian age [1]. Clay minerals usually result from long term alteration of primary minerals by liquid water and on Earth are usually the products of weathering processes. The presence of clay minerals suggests a primary environment completely diffe...

Sealing with waterborne clays is a rapid and low cost method of controlling seepage through porous media whenever the clay source is within economical shipping distance of the sealing site. But more must be learned about this method of sealing before it can be fully utilized. Water impedance of waterborne bentonites, as measured by water loss in the filter press test, was correlated with their ...

Plastic concrete consists of aggregates, cement, water and bentonite, mixed at a high water cement ratio, to produce a ductile material. It is used for creating an impermeable barrier (cut-off wall) for containment of contaminated sites or seepage control in highly permeable dam foundations. The effects of water to binder ratio and clay dosage on mechanical properties of plastic concrete were i...

Clay, as a rock term, describes a soft, loose, earthy material containing particles with an average grain size of less than than 0.004 mm (4 mm) in the Wentworth grain size scale and less than 0.002 mm (2 mm) in most soil investigations. Clay is composed mostly of clay minerals, but may also contain quartz, feldspar, carbonates, ferruginous material, and other non-clay materials. All clays, apa...

Wetlands often act as sinks for uranium and other trace elements. Our previous work at a mining-impacted wetland in France showed that a labile noncrystalline U(IV) species consisting of U(IV) bound to Al-P-Fe-Si aggregates was predominant in the soil at locations exhibiting a U-containing clay-rich layer within the top 30 cm. Additionally, in the porewater, the association of U(IV) with Fe(II)...

When a mass of saturated clay is heated, as in the case of host soils surrounding nuclear waste disposals at great depth, the thermal expansion of the constituents generates excess pore pressures. The mass of clay is submitted to gradients of pore pressure and temperature, to hydraulic and thermal flows, and to changes in its mechanical properties. In this work, some of these aspects were exper...