In situ characterization of colloidal particles under hydrous conditions is one of the key requirements for understanding their state of aggregation and impact on the transport of pollutants in aqueous environments. Scanning transmission X-ray microscopy (STXM) is one of the few techniques that can satisfy this need by providing element- and chemical-state-specific 2-D maps at a spatial resolut...

This research addressed the effect of mineral and organic soil constituents on the fate of organic compounds in soils. Specifically, it sought to determine how the associations between organic chemicals and different soil constituents affect their subsequent biodegradation in soil. Four C-labeled surfactants were aseptically adsorbed to montmorillonite, kaolinite, illite, sand, and humic acids....

Potassium-calcium adsorption kinetics on a Llano vermiculite and an Arizona montmorillonite were studied using a stirred-flow technique. Various experiments were conducted to distinguish between (i) instantaneous equilibrium and time-dependent reactions, and (ii) solution-concentration-dependent kinetic models vs. those that are independent of solution concentration. These experiments included ...

Ice nucleation of ammonia gas exposed montmorillonite mineral dust particles A. Salam, U. Lohmann, and G. Lesins Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Canada Department of Chemistry, University of Dhaka, Dhaka – 1000, Bangladesh Institute of Atmospheric and Climate Science, ETH Zurich, Switzerland Received: 23 October 2006 – Accepted: 14 November 2006 – P...

Periodic application of agrochemicals has led to high cost of production and serious environmental pollution. In this study, the ability of montmorillonite (MMT) clay to act as a controlled release carrier for model agrochemical molecules has been investigated. Urea was loaded into MMT by a simple immersion technique while loading of metalaxyl was achieved by a rotary evaporation method. The su...

Montmorillonite (SWy-2)-chitosan bionanocomposites (SW-CH) were prepared following different methodologies, characterized, and assayed as adsorbents of the herbicide clopyralid (3,6-dichloropyridine-2-carboxylic acid) in aqueous solution and soil/water suspensions, to assess the potential of the materials to prevent and remediate soil and water contamination by anionic pesticides. The SW-CH bio...

nano zno/ montmorillonite composite were prepared by sol gel method under ultrasonic irradiation from directly mixing montmorillonite nano clay into zinc gel. the zn(ch3coo)2.2h2o and montmorillonite nano clay was used as precursor. the zinc acetate was dissolved in di water and, nh3 (aq) solution was dropped into the zinc solution until ph 9 consequently the zinc gel was produced. the montmori...

Partially exfoliated poly (methyl methacrylate) (PMMA) / montmorillonite clay nanocomposite was synthesized via the free radical polymerization of MMA in the presence of alkyl ammonium substituted polysilsesquioxane surfactant-modified clay and AIBN initiator in supercritical CO2. MMT clay was initially cation exchanged with the surfactant to enhance its hydrophobicity and to expand the interla...

A new approach was developed for reducing leaching of herbicides and contamination of groundwater. Liposome-clay formulations of the anionic herbicides sulfometuron and sulfosulfuron were designed for slow release by incorporating the herbicide in positively charged vesicles of didodecyldimethylammonium (DDAB), which were adsorbed on the negatively charged clay, montmorillonite. Freeze fracture...

The present study was carried out on the effect of acid leaching on the modification and structure alteration of montmorillonite. A nanostructured, activated material was prepared by selective leaching of pure smectite clay with different concentrations of sulfuric acid (1 10 N/L) at 85 ̊C for 120 min using a solid/liquid ratio of 1:20 and a reflux system. The Fourier transform infrared (FTIR), ...