We discuss the thermodynamics of physical adsorption of gases in porous solids. The measurement of the amount of gas adsorbed in a solid requires specialized volumetric and gravimetric techniques based upon the concept of the surface excess. Excess adsorption isotherms provide thermodynamic information about the gas-solid system but are difficult to interpret at high pressure because of peculia...

The isothermal adsorption of nicotine from an aqueous solution onto zeolite type USY at temperature range from 298 to 322 K was investigated. It was found that the adsorption isotherms can be described by the Freundlich adsorption isotherm. The density distribution function of adsorption centers has an exponential form and the adsorption isotherms can be fitted by the Freundlich isotherm. The c...

As part of our efforts to model enhanced coalbed methane recovery and CO2 sequestration in coalbeds, we have investigated the pure adsorption isotherm behavior of five dry coals namely, Illinois #6, Wyodak sub-bituminous, Pocahontas, Beulah Zap, and Upper Freeport coal. Using a volumetric technique, isotherms of pure methane, nitrogen, CO2 and ethane were measured at a temperature of 328.15 K (...

The contribution of variable grain sizes to uranium adsorption/desorption was studied using a sediment from the US DOE Hanford site. The sediment was wet sieved into four size fractions: coarse sand (1-2 mm), medium sand (0.2-1 mm), fine sand (0.053-0.2 mm), and clay/silt fraction (<0.053 mm). For each size fraction and their composite (sediment), batch and flow-cell experiments were performed ...

The adsorption behaviour of Methyl violet and Auramine yellow from aqueous solution onto Stishovite clay was investigated as a function of parameters such as initial dye concentration, contact time, p and temperature. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms. Adsorption followed pseudo-second order model. The experimental data fitted well ...

methyl orange is one dye resulted from the textile industry. the aim of this study is to test theadsorption capacity of nickel oxide nanoparticles for removing the methyl orange from aqueoussolution. the parameters studied were the effect of temperature, contact time and initial ph ofsolution. results indicate that the removal efficiency of nickel oxide nanoparticles increases withincreasing co...

Cow bone charcoal (CBC) was synthesized and used for the removal of metals ions (manganese, iron, nickel and copper) from aqueous solutions. Two different adsorption models were used for analyzing the data. Adsorption capacities were determined: copper ions exhibit the greatest adsorption on cow bone charcoal because of their size and pH conditions. Adsorption capacity varies as a function of p...

Water adsorption isotherms are calculated by grand canonical Monte Carlo simulations for the SPC/E water model in carbon nanopores at 298K. The pores are of slit or cylindrical morphology. Carbon-slit pores are of widths 0.8, 1.0 and 1.6 nm. The simulated single-walled carbon nanotubes are of 1.4 and 2.7 nm diameter ((10:10) and (20:20) respectively). In all cases considered, the adsorption iso...

Porous materials adsorb H2 through physisorption, a process which typically has a rather low enthalpy of adsorption (e.g. ca. 4 to 7 kJ mol(-1) for MOFs), thus requiring cryogenic temperatures for hydrogen storage. In this paper, we consider some of the issues associated with the accurate characterisation of the hydrogen adsorption properties of microporous materials. We present comparative gra...

The adsorption equilibrium isotherms of five phenolic compounds from aqueous solutions onto granular activated carbon (GAC) were studied and modeled. Phenol (Ph), 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2,4-dichlorophenol (DCP), and 2,4,6-trichlorophenol (TCP) were chosen for the adsorption tests. To predict the adsorption isotherms and to determine the characteristic parameters for proce...