Desorption Kinetics at the Solid/Solution Interface: A Theoretical Description by Statistical Rate Theory for Close-to-Equilibrium Systems

Abstract

Modeling of desorption kinetics plays an important role for better understanding of this phenomena. In the present work the kinetics of solute desorption at the solid/solution interface has been studied by statistical rate theory (SRT) when the system is close to equilibrium. It is demonstrated that, for desorption, a pseudo-first-order equation can be derived from the SRT equation when the system is close to equilibrium. On the basis of numerically generated points (t; q) by the SRT equation, it is shown that it is not possible to apply the pseudo-first-order equation for modeling of whole kinetic desorption data. The results of numerical analysis are in good agreement with our theoretical derivation of the pseudo-first-order equation for desorption systems close to equilibrium. Finally, the results of the present theoretical study were confirmed by analysis of two experimental systems.