The percentage of organic carbon contents of 62 bottom sediments in Pahang riverestuary were analyzed using the wet dichromate oxidation method. The sediments particle sizes at the same stations were also measured using the dry sieving and laser diffraction methods. In this study, the concentrations of organic carbon are relatively higher during pre-monsoon season and become much lower during t...

We show that 85% of variation in total organic carbon can be explained by mineral surface area in a black shale deposit from two locations in the late Cretaceous Western Interior Seaway, United States. This relation suggests that, as in modern marine sediments, adsorption of carbon compounds onto clay mineral surfaces played a fundamental role in the burial and preservation of organic carbon. O...

this research was conducted to study the effect of land use change on some physical fractionation component of organic matter and some of its quality factors. therefore, two uncultivated and cultivated (such as rotational cropping and sugarcane) were selected in khuzestan province. disturbed and undisturbed soils were sampled from 0-30 and 30-60 cm depths. total n, oc, dispersible clay (dc), ag...

Fifty-seven typical surface soils and 108 deeper soils were collected from five former industrial sites in Beijing and concentrations of total Hg (SigmaHg) as well as pH, total carbon (TC), total nitrogen (TN), total sulfur, and dissolved organic carbon concentrations determined. The mean concentration of SigmaHg in surface soils was significantly greater than background concentrations in the v...

The burial of organic carbon in marine sediments removes carbon dioxide from the ocean-atmosphere pool, provides energy to the deep biosphere, and on geological timescales drives the oxygenation of the atmosphere. Here we quantify natural variations in the burial of organic carbon in deep-sea sediments over the last glacial cycle. Using a new data compilation of hundreds of sediment cores, we s...

this research evaluates the efficiency of nanosized zno in the catalytic ozonation of 4-chloro-2-nitrophenol and determines the effect of ph on heterogeneous catalytic ozonation. the combined use of ozone and zno catalyst leads to conversion of 98% 4-chloro-2-nitrophenol during 5 min. in addition, it was found that in zno catalytic ozonation, the degradation efficiency of 4-chloro-2-nitrophenol...

air pollution has always been a major problem in metropolises. volatile organic compounds are one of the major pollutants that are caused by incomplete combustion of fuels in vehicles and gasoline evaporation, especially in fueling stations. removing these pollutants through traditional methods has always been considered. the paper investigates and studies chemical adsorption behavior of benzen...

objective: returning crop residue to the soil exerts favorable effects on physical and chemical properties of soil. in fact, the plant residues can affect soil conditions such as ph and important role in soil fertility and cycling of elements in the soil may have. in addition to the role of the organic matter from decomposition of crop residue in increasing the concentration of micronutrients i...

abstract one of the methods for improving soil physical quality of arid and semiarid regions is the application of cheap organic conditioners such as sewage sludge. this research was conducted in large pots (50 cm diameter, 25 cm height) to study the effects of tabriz petrochemical biological sludge at 4 rates (25, 50, 75 and 100 tons/ha) on organic carbon (oc), mean weight diameter (mwd) of ag...

conclusions results indicated that annular fluidized bed reactor’s adsorbers are useful techniques for vocs adsorption. comparison of two particle ranges indicates that in all concentrations and all flow rates of the experiments, smaller particle size adsorption are better. in superficial velocity above the minimum fluidization velocity, pressure drop of fluidized beds are less than the pressur...