The knowledge of sorption processes of nonelectrolytes in solution by solid adsorbents implies the study of kinetics, equilibrium, and thermodynamic functions. However, quite frequently the equilibrium isotherms are studied by comparing them with those corresponding to the Giles et al. classification (1); these isotherms are also analyzed by fitting them to equations based on thermodynamic or k...

The efficiency of four low-cost sorbent materials namely peas husk, broad bean husk, medlar peel and fig leaves, for removing cadmium ions from aqueous solutions, in single systems, has been investigated in batch mode. Kinetic data and equilibrium sorption isotherms were measured. Kinetics of cadmium sorption was contact time, initial cadmium concentration and sorbent type dependent. For a give...

Solute transport with nonlinear adsorption occurs in many situations involving inorganic chemical and metal contamination in soil and groundwater systems. The resulting isotherms can be highly nonlinear, and numerical solutions of the transport equation can encounter severe convergence difficulties. An analytical solution is developed for simulating one-dimensional transport in the layered soil...

We have studied adsorption in regular, self-ordered alumina pores open at both ends or only at one end. The straight, non-connected pores have diameters ranging from 22 to 83 nm, with a relative dispersion below 1% in the pore size. Adsorption isotherms measured in open pores with a torsional microbalance show pronounced hysteresis loops characterized by nearly vertical and parallel adsorption ...

We study the influence of the relative size of the reservoir on the adsorption isotherms of a fluid in disordered or inhomogeneous mesoporous solids. We consider both an atomistic model of a fluid in a simple, yet structured pore, whose adsorption isotherms are computed by molecular simulation, and a coarse-grained model for adsorption in a disordered mesoporous material, studied by a density f...

in the present investigation, dead bacterium biomass streptomyces rimosus was used as an inexpensive and efficient biosorbent for cr (iii) removal from aqueous solution. the bacterial biomass was treated with 0.1 m naoh. sorption level of 65 mg/g was observed at ph 4.8 while precipitation effect augmented this value at higher ph range. chromium desorption increased with decreasing desorption ag...

This study investigated the power of hydroxyapatite adsorbent prepared by a combined precipitation-microwave method, for removing a cationic dye methylene blue in aqueous media. The used adsorbent was characterized by X-ray diffraction (XRD) and infrared spectroscopy (IR). The adsorption tests were conducted in batch mode. The effect of temperature, the pH of the solution and the mass of the ad...

In the present research, the potential of two biochars produced by the thermal decomposition of wheat straw (BCS) and wicker (BCW) for Cr(VI) ions removing from wastewater was investigated. The pH and the presence of chlorides and nitrates were also investigated. The Freundlich and Langmuir models were applied for the characterization of adsorption isotherms. The Langmuir model has better fitti...

The binary sorption of copper and nickel ions onto peat has been studied. Equilibrium isotherms have been determined for three di!erent copper : nickel molar concentration ratios. The experimental results have been analysed using an extended multicomponent Langmuir equation with a competition term but the correlation between the experimental and the predicted values was poor. An interaction fac...

The mechanism of the displacement washing of the bed of pulp fibers is mathematically modeled by the basic material balance equation. Linear as well as non-linear adsorption isotherms are used to describe the relationship between the concentration of the solute in the liquor and concentration of the solute on the fibers. In the present study, the numerical solutions are obtained of pulp washing...