Two natural clays (kaolinite and montmorillonite) were deposited onto a platinum electrode surface using two deposition techniques and under different experimental variables. For both clays, the percentages of surface coverage (%y) were optimized in the 75 96% range. A greater surface coverage was observed at higher temperatures for both clays, which confirms the endothermic nature of the depos...

Patterns of plant distribution by palaeoenvironment were examined across the Pennsylvanian-Permian transition in North-Central Texas. Stratigraphically recurrent packages of distinct lithofacies, representing different habitats, contain qualitatively and quantitatively different macrofloras and microfloras. The species pools demonstrate niche conservatism, remaining closely tied to specific hab...

The effects of ionic strength of the permeating fluid on the clogging of soil filters and drainage layers are addressed using both experimental and modeling investigations. In the experimental phase, a sandy soil representative of soil filters was permeated with pore fluids containing kaolinite particles. The ionic strength of the solutions was changed using different concentrations of NaOH and...

Abstraet--Bis-ethyl 2-hexylphosphoric acid (di-2 EHPA) dissolved in decane is chemisorbed on kaolinite and montmorillonite dispersed in an acidic aqueous solution. The adsorption results in the formation of complexes with the surface cations of the clays. The adsorption isotherms are of the Langmuir type and reveal a limiting value of adsorption on H+-kaolinite of 12.2 mg/g, comparable to that ...

The clay mineralogy of pyroclastic Nb(Ta)-Zr(Hf)-REE-Ga mineralization in Late Permian coal-bearing strata from eastern Yunnan Province; southwest China was investigated in this study. Samples from XW and LK drill holes in this area were analyzed using XRD (X-ray diffraction) and SEM (scanning electronic microscope). Results show that clay minerals in the Nb-Zr-REE-Ga mineralized samples are co...

Antibiotic ciprofloxacin (CIP) is immobile in the subsurface but it has been frequently detected in the aquatic system. Therefore it is important to investigate the factors impacting CIP's mobilization in aquifer. Laboratory columns packed with sand were used to test colloid-facilitated CIP transport by 1) using kaolinite or montmorillonite to mobilize presorbed-CIP in a column or 2) co-transpo...

[1] Mawrth Vallis contains one of the largest exposures of phyllosilicates on Mars. Nontronite, montmorillonite, kaolinite, and hydrated silica have been identified throughout the region using data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). In addition, saponite has been identified in one observation within a crater. These individual minerals are identified and disti...

The effects of polyacrylamide (PAM) molecular weights (MWs) on the PAM adsorption capacities and PAM-mediated flocculation of kaolinite suspensions were investigated using a series of nonionic PAMs with different MWs. Adsorption tests using aqueous kaolinite suspensions dosed with a series of PAMs with MWs of 1.5 kg/mol, 10 kg/mol, 0.6–1 Mg/mol, 5–6 Mg/mol, and 18 Mg/mol (referred to as 1.5 K, ...

-The crystal structure of Keokuk kaolinite, including all H atoms, was refined in space group C1 using low-temperature (1.5 K) neutron powder diffraction data (~ = 1.9102 A) and Rietveld refinement/ difference-Fourier methods to R,,,p = 1.78%, reduced x 2 = 3.32. Unit-cell parameters are: a = 5,1535(3) /~, b = 8.9419(5) &, c = 7.3906(4) &, a = 91.926(2) ~ = 105.046(2) ~ 7 = 89-797(2) ~ and V= 3...

pH and compound ionization. In contrast to the case for neutral PACs, an equilibrium partition model, whereby Adsorption of quinoline (pKa 5 4.92) and background electrolyte NHCs sorb in direct proportion to fOC, is not supported (LiCl) onto specimen kaolinite was measured as a function of surfaceby the available data. Retention of cationic NHCs may bound humic acid (HA) concentration ( fOC 5 0...