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...

Sorption of P to the bed sand medium is a major removal mechanism for P in subsurface flow constructed reed beds. Selecting a sand medium with a high P-sorption capacity is therefore important to obtain a sustained P-removal. The objective of this study was to evaluate the P-removal capacities of 13 Danish sands and to relate the removal to their physico-chemical characteristics. The P-removal ...

Chemical composition of interfaces—free surfaces and grain boundaries—is generally described by the Langmuir–McLean segregation isotherm controlled by Gibbs energy of segregation. Various components of the Gibbs energy of segregation, the standard and the excess ones as well as other thermodynamic state functions—enthalpy, entropy and volume—of interfacial segregation are derived and their phys...

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...

The sorption isotherm is important information for evaluating the ability of an adsorption system to treat the industrial waste water. In this study, eleven datasets from literatures were selected and three two-parameter and threeparameter equations were used to evaluate adsorption systems. Quantitative criteria included six error functions, and the quantitative criterion was residual plots. Is...

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...

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 ...

A consistent description of the hydrogen permeation through metal membrane based on hydrogen chemical potential proposed has been explained in detail. The hydrogen flux is proportional to the PCT factor, fPCT, consistently, which reflects the shape of the pressure-composition-isotherm (PCT curve) of the material. In addition, in view of the PCT factor, fPCT, and the ductile-to-brittle transitio...

H nuclear magnetic resonance (NMR), supported by a measurement of the degree of hydration using X-ray diffraction, has been used to fully characterise the nano-scale porosity and composition of calcium-silicate-hydrate (C-S-H), the active component of cement. The resultant “solid” density and composition are 3 g/cm 68 . 2 = ρ ; (Ca)1.53. (Si0.96,Al0.04)O3.51.(H2O)1.92 for an underwater cured, n...