This study investigates the effect of surface acidity and basicity of aluminas on asphaltene adsorption followed by air oxidation. Equilibrium batch adsorption experiments were conducted at 25°C with solutions of asphaltenes in toluene at concentrations ranging from 100 to 3000 g/L using three conventional alumina adsorbents with different surface acidity. Data were found to better fit to the F...

Crayfish carapace, a plentiful waste in China, was applied to remove divalent heavy metal ions—copper (Cu), cadmium (Cd), zinc (Zn), and lead (Pb)—from wastewater. The adsorption capacities of crayfish carapace micro-powder (CCM) for heavy metal ions were studied with adsorbent dosages ranging from 0.5–2.5 g/L and with initial metal concentrations ranging from 50–250 mg/L. CCM particle size, in...

The effect of temperature on the adsorption and retention behaviors of a low molecular weight compound (phenol) on a C18-bonded silica column (C18-Sunfire, Waters) from aqueous solutions of methanol (20%) or acetonitrile (15%) was investigated. The results of the measurements were interpreted successively on the basis of the linear (i.e., overall retention factors) and the nonlinear (i.e., adso...

In chromatographic separations involving elutes with large differences in the molecular size, the adsorption saturation capacities of the elutes may differ because of the differences in the degree of size exclusion. With uneven saturation capacities, isotherm crossovers may occur, which often results in selectivity reversal. In this work, a new multicomponent isotherm has been developed for thi...

Methane adsorption on positively charged aggregates of C60 is investigated by both mass spectrometry and computer simulations. Calculated adsorption energies of 118-281 meV are in the optimal range for high-density storage of natural gas. Groove sites, dimple sites, and the first complete adsorption shells are identified experimentally and confirmed by molecular dynamics simulations, using a ne...

a good understanding of adsorption equilibrium and thermodynamics is required to design and operate an adsorption process. this study was conducted to assess the adsorption percentage of pb2+ ions as a function of contact time, solution ph and temperatures, and adsorbent dosage through a series of batch experiments. the methods including zeta potentials, specific surface area measurements and t...

   In this study, cadmium sulfide nanoparticles (CdS NPs) were prepared, characterized and used as a new adsorbent for simultaneous removal of Pb(II) and Cu(II) ions from aqueous solutions. Using a batch adsorption method, the effects of solution pH, contact time, adsorbent dose, and temperature were studied and optimized. Removal efficiencies, higher than 98% were obtained for both the met...

Equilibrium adsorption property of multi-walled carbon nanotubes with OH group was studied using experimental design for the adsorption of CO2 , CH4 and H2 . The effect of temperature, pressure, their binary interactions and quadratic terms were studied for adsorption capacity of nanotubes and the results were analyzed by the face centered central composite design method and analysis of varianc...

The interaction between some heavy metal ions such as of Pb(II), Cd(II) and Cu(II) ions from aqueous solution adsorbed by single walled carbon nanotube (SWCNTs) and carboxylate group functionalized single walled carbon nanotube (SWCNT-COOH) surfaces were studied by atomic absorption spectroscopy. The effect of contact time, pH, initial concentration of ion, ionic strength and temperature on the...