The presence of long-lived radionuclides in natural aquatic systems is of great environmental concern in view of their possible migration into biospheres of mankind. Trivalent actinides such as (241/243)Am can contribute a great deal to radioactivity for several thousand years. This migration is significantly influenced by various factors such as pH, complexing ions present in aquatic environme...

BACKGROUND AND OBJECTIVES Biofilms are structural communities of bacterial cells enshrined in a self produced polymeric matrix. The studies on biofilm formation of Pasteurella multocida have become imperative since it is a respiratory pathogen and its biofilm mode could possibly be one of its virulence factors for survival inside a host. The present study describes a biofilm assay for P. multoc...

Bentonite is a preferred buffer and backfill material for deep geological disposal of high-level nuclear waste (HLW). Bentonite does not retain anions by virtue of its negatively charged basal surface. Imparting anion retention ability to bentonite is important to enable the expansive clay to retain long-lived (129)I (iodine-129; half-life = 16 million years) species that may escape from the HL...

Toxicity Summary: IDENTIFICATION: Bentonite is a rock formed of highly colloidal and plastic clays composed mainly of montmorillonite and produced in situ devitrification of volcanic ash. It may contain feldspar, cristobalite and crystaline quartz. Major uses of bentonite include binding foundry sand in molds, absorbing grease, oil and animal wastes; palletizing taconite iron ore and improving ...

Chemical modifications of clay to remove methylene blue (MB) from aqueous solutions at room temperature were compared. Natural bentonite (NC) was modified by cation exchange with hexadecyltrimethylammonium chloride (HC), bencyltriethylammonium chloride (BC), and tetramethylammonium chloride (TC) to reverse the surface polarity of the hydrophilic bentonite. The adsorption of MB was studied and f...

Bentonites are widely used for waste repository systems because of their hydrodynamic, surface and chemical-retention properties. MX 80 bentonite (bentonite of Wyoming) contains approximately 85% Na/Ca-montmorillonite and 15% accessory minerals. The dominant presence of Na/Ca-montmorillonite in this clay mineral could cause it to perform exceptionally well as an engineered barrier for a radioac...

One of the major sources, which wastes the environment is the wastewater produced from the human activity. At present, in order to decrease waste hazards and to restrict the resulted effects on the environment, investigators studying the possibility of using new methods and materials to treat wastewater. Coagulation and flocculation process are physical-chemical methods that widely used in the ...

A conventional liner with a good performance against inorganic contaminants with a minimal hydraulic conductivity does not usually perform well for retention/removal of leachates containing organic contaminants. Organic modification of clay can render the naturally organophobic clay to be organophilic. Incorporation of modified organo clay along with unmodified inorganic clay in liner systems c...

Three-layered clay minerals such as montmorillonite (bentonite) exhibit very short transverse relaxation times. This is especially true for samples with relatively low water contents in the region of 20% to 30%, which is the water content typically used in environmental technology applications (e.g., as a mineral liner material for landfills). The diffusion of water in samples with such short t...

In this study, removal of copper (Cu(2+)) and zinc (Zn(2+)) from aqueous solutions is investigated using Cankiri bentonite, a natural clay. During the removal process, batch technique is used, and the effects of pH, clay amount, heavy metal concentration and agitation time on adsorption efficiency are studied. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms are applied in order to...