The aggregation and colloidal stability of three, commercially-available, gamma-aluminum oxide nanoparticles (γ-Al₂O₃ NPs) (nominally 5, 10, and 20-30 nm) were systematically examined as a function of pH, ionic strength, humic acid (HA) or clay minerals (e.g., montmorillonite) concentration using dynamic light scattering and transmission electron microscopy techniques. NPs possess pH-dependent ...

Spray dry granulation of clay minerals was studied to obtain clay mineral base support material for metallocene supported olefin polymerization catalysts. The morphology of the granules was strongly influenced by the nature of the clay mineral itself. Because of swelling characteristics of montmorillonite, its water dispersion was highly viscous even in the low slurry concentration (< 4 wt %). ...

A nearly monomineralic 1.5 m thick bentonite bed sampled in Melo (Uruguay) appears to be a pure high-charge montmorillonite: [Si3.94 Al0.06] (Al1.40 Fe0.11 Ti0.02 Mg0.49 Mn0.01) O10 (OH)2 Na0.01 K0.08 Ca0.18. However, contrasting swelling behaviors have been evidenced by fitting the experimental X-ray diffraction patterns recorded on oriented preparations of the same sample in different saturat...

OBJECTIVES The aim was to evaluate the adsorbing effect of montmorillonite on uric acid, promoting diffusion of uric acid from blood to intestine, preventing absorption of uric acid in intestine and reducing uric acid level in serum. METHODS The adsorbing effect of montmorillonite on uric acid was observed in vitro. The intestine and blood vessel of rats were circularly perfused with intestin...

In order to evaluate the effects of parent material on clay mineralogy in northface of the Elborz mountain area that is covered with deciduous trees, five mountain physiographical units with dolomite, sandstone, marl, limestone and conglomera parent material were selected and in each physiographical unit some soil profiles were studied. Soil samples were taken from different horizons and leyers...

The coadsorption of ciprofloxacin (Cip) and Cu(II) on montmorillonite and kaolinite was studied between pH 4.0 and 9.5. At pH < 5.0, Cu(2+), Cip(+) and [Cu(II)(Cip(+/-))](2+) were the main species in solution. Between pH 5.0-7.0 [Cu(II)(Cip(+/-))](2+) was the dominant complex species. Above pH 8.0 [Cu(II)(Cip(-))(2)](0) precipitated. The presence of Cu(II) exerted no effect on the Cip sorption ...

In this study, we investigate the interaction of Rhodopseudomonas Palustris (R. Palustris) with montmorillonite clay. The adsorption of bacteria on the clay surface was also determined as a function of the initial bacterial quantity, pH, temperature and ionic strength. At different initial bacterial quantities, the percentage of bacteria adsorbed ranged from 61.07% to 77.57%, and the higher per...

The sorption speciation of Ni(II) on Ca-montmorillonite was evaluated using a combination of batch experiments, extended X-ray absorption fine structure (EXAFS) spectroscopy and modeling. The pH and temperature at the aqueous-montmorillonite interface affects both the extent of Ni(II) sorption as well as the local atomic structure of the adsorbed Ni(II) ions. At 0.001 mol L(-1) Ca(NO(3))(2) and...

Organic matter in sewage, soil, and aquatic systems may enhance or inhibit the infectivity of viruses associated with particulates (e.g., clay minerals, sediments). The purpose of this investigation was to identify the mechanisms whereby organic matter, in the form of defined proteins, affects the adsorption of reovirus to the clay minerals kaolinite and montmorillonite and its subsequent infec...