The toxicity of lead (Pb) to fungi in pure culture was influenced by several abiotic factors: pH, inorganic anions, clay minerals, and particulate (humic acid) and soluble organic matter. The toxicity of Pb was potentiated under acidic conditions (pH 5 and 6), and phosphate or carbonate anions reduced the toxicity, apparently as a result of the formation of sparingly soluble Pb salts. Clay mine...

Organic matter removal is accomplished rapidly and efficiently without removing carbonates by treating samples wi~h a sodium hypochlorite solution. Quantities of organic matter lefr in samples by this treatment are commonly less than remain after hydrogen peroxide treatment of acidified samples. Stable suspensions result from the use of a sodium carbonate-sodium bicarbonate solution to wash and...

Shallow-buried fluvial mudstones are of great significance as potential top seals for natural gas accumulations in the Zhanhua depression. Four samples were chosen to represent range fine-grained microfacies, from clay-rich silt-rich cemented, and mercury injection capillary pressure (MICP) porosimetry is combined with Scanning Electron Microscopy (SEM) characterize microstructure pore systems ...

In 1976 a National Research Council Panel estimated that Western World lithium reserves and resources totaled 10.6 million tonnes as elemental lithium. Subsequent discoveries, particularly in brines in the southern Andes and the plateaus of western China and Tibet have increased the tonnages significantly. Geothermal brines and lithium bearing clays add to the total. This current estimate total...

Soil cation exchange capacity (CEC) depends on the extent and negative charge density of surfaces of soil mineral and organic components. Soil water sorption also depends on the extent of such surfaces, giving thus way to significant relationships between CEC and hygroscopic moisture (HM) in many soils. In this work, we explored whether CEC could be accurately predicted from HM in agricultural ...

Many soils have clay-enriched horizons that are thought to result from pedogenic processes. Various hypotheses are proposed for expected clay size-distributions in soil profiles. The average size of clay crystallites determined by the amount of broadening of x-ray diffraction peaks ranged from 160 to >2000A 0 , but the lack of trends in four loess-de• rived soils did not permit the hypotheses t...

this study was conducted to characterize the reactivity of carbonates in the surface horizons of 20 soils (entisols and aridisols) from central region of iran. the samples were analyzed for calcium carbonate equivalent (cce), active calcium carbonate equivalent (acce), non-active calcium carbonate equivalent (n.acce), carbonate mineralogy and surface area of carbonates (ssa) through n2 adsorpti...

Examination of clays from surface and basal horizons of four Scottish soils by differential thermal analysis, before and after heating to 600~ and by infra-red spectroscopy indicates that these contain a proportion of highly hydrated amorphous material, resembling allophane in its properties, and that this component is particularly high in clays from the surface horizons with the greatest organ...

expansive behavior is usually observed in soils, which contain fractions of clay minerals in their composition. water absorption of clay particles and change of natural water content of soil up to plastic limit and down to shrinkage limit will cause significant volume change in expansive soils and will result in severe damages to the structures, buildings and foundations. swelling potential is ...