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...

In this research by equilibrium adsorption isotherms of vitamin B2 (Ribo Flavin) on carbon nano-tubes having the multi wall through several discontinues method has been studied.with the help of spectro photometer (UV / VIS) adsorption chart based on the wavelength of vitamin B2 has been obtained, and the relevant graph is plotted .by considering factor of concentration, the concentration necess...

A favorable isotherm open to the right to some extent is better than a linear isotherm to give shorter column height in pressure swing adsorption(PSA). We face to a problem how favorable isotherm is actually favorable in PSA operation. The purpose of this paper is to propose how to construct such a custom made isotherm which optimizes the PSA processes. The PSA mod...

Comparison analysis of linear least-square method and non-linear method of three widely used isotherms (Langmuir, Freundlich, and Redlich-Peterson) were examined to experiment with Remazol Red (C.I. 18221) onto pistachio nut shells at a solution temperature of 293 K. All three isotherm equations showed a better fit to the experimental equilibrium data. The results show that the Langmuir model s...

ethyl benzene used increasingly each year is the raw material of producing styrene monomer. this substanceis produced from benzene alkylation with ethylene or ethanol, depending on the availability and cost of rawmaterials. in this study benzene alkylation in the presence of ethanol in a catalytic fixed bed reactor inthree states of isotherm, adiabatic and non-isotherm-non-adiabatic is mathemat...

Analytical isotherm equations such as Langmuir and Freundlich isotherms are widely used for modeling adsorption data. However, these isotherms are primarily useful for simulating data collected at a fixed pH value and cannot be easily adapted to simulate pH-dependent adsorption effects. Therefore, most adsorption studies currently use numerical surface-complexation models (SCMs), which are more...

The present study reports the kinetic and absorption performance of novel nanometre scale hydroxyapatite (HAP) absorber synthesised from a combined ultrasound and microwave based technique for the removal of metal ions (Fe, Cu and Zn) from aqueous solutions. After powder characterisation was carried out using XRD, SEM, EDS and FT-IR, batch adsorption studies were carried out. Kinetic studies es...

A preferential interaction quadratic isotherm model for hydrophobic interaction chromatographic systems is presented in this paper. In this isotherm, the nonlinear effect of salt on the capacity factor is described using the preferential interaction model developed by Perkins et al. [J. Chromatogr. A, 766 (1997) 1]. This is then coupled with a quadratic nonlinear isotherm to describe nonlinear ...

This paper presents the feasibility of removal of MB dye from aqueous solution using activated carbon prepared from Usoro fiber (Adenia lobata). FTIR analysis revealed that many functional groups were present on the surface of the adsorbent. The adsorption Kinetics was analyzed by pseudo first order, pseudo second order and intra particle diffusion kinetics models. Results showed that MB adsorp...

We compute the thermal conductivity and diffusion coefficient of supercritical carbon dioxide along the 313 K isotherm using non-equilibrium molecular dynamics. Comparisons are made with experiment at four densities corresponding to pressures of 30, 70, 200 and 500 bar. Two intermolecular potential models for carbon dioxide are compared. INTRODUCTION In a previous paper (Wang and Cummings, 1988...