pedogenesis and clay mineralogy of soils and rock samples were studied in a transect of calcareous, gypsiferous, saline soils and sediments of bakhtegan lake bank in southern iran. the main objectives of study were to determine the occurrence of clay minerals and factors controlling their distribution pattern and relative abundance in soils and parent materials. the soil parent material is high...

To control the molecular organization of octadecyl rhodamine B (RhB18), hybrid Langmuir–Blodgett monolayers containing clay minerals were prepared. The orientation and conformation of the RhB18 molecule were analyzed by polarized attenuated total reflection Fourier transform infrared (ATR–FTIR) spectroscopy and fluorescence spectroscopy. Monomers and dimers of RhB18 were observed by UV-Vis abso...

In environmental studies, we need to be able to predict the behaviour of contaminants in more or less complex physico-chemical contexts. The improvement of this prediction partly depends on establishing thermodynamic models that can describe the behaviour of these contaminants and, in particular, the sorption reactions on mineral surfaces. In this way, based on the mass action law, it is possib...

Arsenic (As) contaminated aquifers contain iron minerals and clays that strongly bind As at their surfaces. It was suggested that As mobilization is driven by natural organic matter (including fulvic acids (FA) and humic acids (HA)) present in the aquifers either via providing reducing equivalents for reductive dissolution of Fe(III) (hydr)oxides or via competitive desorption of As from the min...

Essene and Peacor (1995 = " E P " ) published a general review of clay mineral thermometry, the stability of clay minerals and the relevance to natural clay mineral assemblages. Some of the conclusions in that paper have been criticized by Aja and Rosenberg (1996 = "AR") . Our paper dealt with some issues about which there has been healthy (and sometimes highly charged) debate. Such dialogue no...

Paleoclimate was reconstructed by the clay mineral assemblages of shale units of Pabdeh (PaleoceneOligocene), Gurpi (Upper Cretaceous), Kazhdumi (Albian-Cenomanian) and Gadvan (Aptian-Neocomian) formations in the Bangestan anticline. To compare with clay minerals assemblages in these formations, selected samples also taken from available formations in drilled wells in Ahvaz, Marun, Karanj, and ...

Methyl chloroform (1,1,1-trichloroethane, CH 3 CCl 3) was found to decompose heterogeneously on seven types of standard clay minerals (23 materials) in dry air at 313 K in the laboratory. All reactions proceeded through the elimination of HCl; CH 3 CCl 3 was converted quantitatively to CH 2 =CCl 2. The activities of the clay minerals were com-5 pared via their pseudo-first-order reaction rate c...

Flotation of soluble salt minerals such as potash, trona and borax exhibits similarities because all are conducted in their brine solutions. The most commercially important boron minerals in the world are borax (Na2B4O7.10H2O), colemanite (Ca2B6O11.5H2O), ulexite (NaCaB5O9.8H2O), and kernite (Na2B4O7.4H2O). Most of them contain low grades when mined and must be upgraded by mineral processing te...

Smectites or swelling clay minerals are naturally occurring nanomaterials that can be fully delaminated to elementary clay mineral platelets in dilute aqueous dispersion. This review article gives an overview of the recent progress on how the elementary clay mineral platelets can be reorganized in monolayered or multilayered hybrid nanofilms by layer-by-layer assembly or the Langmuir-Blodgett t...

-The addition of a 10% talc internal standard to North Pacific sediments allows the relative abundances of clay minerals to be determined both accurately and precisely by X-ray powder diffractometry. Linear programming can be used to generate factors for converting talc-normalized peak areas to weight percentages; hence, absolute clay-mineral abundances can be estimated. This procedure minimize...