cadmium (cd) concentration in soil solution and its bioavailability is controlled by sorption-desorption reactions. the objective of this research was to compare cd adsorption behavior in six calcareous and four acid soils. soil samples were equilibrated with 0.01 m ca(no3)2 containing 25 to 3200 mg cd l−1. results showed that the tendency for adsorption was high at low cd concentrations (0-400...

During recent years, major progress has been made in the understanding of the adsorption, pore condensation and hysteresis behavior of fluids in novel ordered nanoporous materials with well defined pore structure. This has led to major advances in the structural characterization by physical adsorption, also because of the development and availability of advanced theoretical procedures based on ...

Removal of Pb 2+ from aqueous solutions using coconut shell carbons produced by KOH activation is performed in this paper. Morphology and pore structure characteristic of coconut shell carbons are analyzed by SEM and nitrogen adsorption techniques. Effects of adsorbent concentration, agitation time and initial ion concentration on the adsorption behavior are investigated, and adsorption isother...

Using density functional theory augmented with state-of-the-art van der Waals corrections, we studied the geometric and electronic properties of nonplanar chlorogallium-phthalocyanine GaClPc molecules adsorbed on Cu(111). Comparing these results with published experimental data for adsorption heights, we found indications for breaking of the metal-halogen bond when the molecule is heated during...

Many important industrial separation processes based on adsorption operate close to saturation. In this regime, the underlying adsorption processes are mostly driven by entropic forces. At equilibrium, the entropy of adsorption is closely related to the enthalpy of adsorption. Thus, studying the behavior of the enthalpy of adsorption as a function of loading is fundamental to understanding sepa...

In this paper, the simplified local density (SLD) theory is combined with the ESD equation of state to study the adsorption of solutes from supercritical carbon dioxide onto activated carbon. Firstly the model was applied to fit the adsorption of toluene+CO2 and benzene+CO2 by using only two temperature-independent parameters. It was shown that this theoretical model is capable of describing th...

methoxy polyethylene glycol modified magnetite nanoparticles (pegmns) were synthesized and were characterized by scanning electron microscopy (sem), vibrating sample magnetometer (vsm), and x-ray diffraction (xrd) . the adsorption of diazinon onto (pegmns) was investigated by uv spectrophotometry at 236 nm, through batch experiments. the effects of adsorbent dosage, solution ph, contact time, s...

Plutonium (Pu) adsorption to and desorption from mineral phases plays a key role in controlling the environmental mobility of Pu. Here we assess whether the adsorption behavior of Pu at concentrations used in typical laboratory studies (≥10(-10) [Pu] ≤ 10(-6) M) are representative of adsorption behavior at concentrations measured in natural subsurface waters (generally <10(-12) M). Pu(V) sorpti...

BACKGROUND AND HYPOTHESIS In the oil industry, asphaltenes are known for their tendency to aggregate in solution and to deposit on surfaces, with both properties being connected with operational problems associated with recovery, production and refining. Interactions involving asphaltenes and other crude oil components have been a major aspect of investigation in attempting to understand the fu...

ordered mesoporous carbon cmk-3 (omc) have been synthesized using mesoporous sba-15 silica as template and modified with cobalt carbonate. morphologies and surface texturing of materials werecharacterized by x-ray diffraction (xrd), scanning electron microscopy (sem) and n2 adsorption-desorptionisotherms. the cobalt modified ordered mesoporous carbon were found to have a surface area of 490.06m...