Fractal-Like Adsorption Kinetics at the Solid/Solution Interface

Abstract

The kinetics of adsorption processes at the solid/solution interface has been studied by using a fractal-like concept. For the first time, one possible physical meaning for fractal-like adsorption kinetics which indicates that sorption rate coefficient at solid/solution interface is a function of time is presented. So, new kinetic models have been presented by a combination of the fractal-like approach and integrated kinetic Langmuir equation (IKL), mixed 1,2-order equation (MOE), and statistical rate theory (SRT). The fractal-like SRT rate equation has been solved at two limiting conditions, one at initial times of adsorption and the other close to equilibrium. The new parameter (α) which has appeared in these models affects the rate of sorption. Fractal-like IKL (or fractal-like MOE) and also fractal-like SRT models have been used to analyze different experimental data. The obtained results indicate that the variation of initial concentration of solute and stirring rate of solution affect both “α” and the rate coefficient.