Diffusion in Heterogenous Media and Sorption—Desorption Processes

We investigate particle diffusion in a heterogeneous medium limited by a surface where sorption–desorption processes are governed by a kinetic equation. We consider that the dynamics of the particles present in the medium are governed by a diffusion equation with a spatial dependence on the diffusio...

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Bibliographic Details
Main Authors: Ana Paula S. Koltun, Ervin Kaminski Lenzi, Marcelo Kaminski Lenzi, Rafael Soares Zola
Format: Article
Language:English
Published: MDPI AG 2021-10-01
Series:Fractal and Fractional
Subjects:
Online Access:https://www.mdpi.com/2504-3110/5/4/183
Description
Summary:We investigate particle diffusion in a heterogeneous medium limited by a surface where sorption–desorption processes are governed by a kinetic equation. We consider that the dynamics of the particles present in the medium are governed by a diffusion equation with a spatial dependence on the diffusion coefficient, i.e., <i>K</i>(<i>x</i>) = <i>D</i>|<i>x</i>|<sup>−<i>η</i></sup>, with −1 < <i>η</i> and <i>D</i> = <i>const</i>, respectively. This system is analyzed in a semi-infinity region, i.e., the system is defined in the interval [0,∞) for an arbitrary initial condition. The solutions are obtained and display anomalous spreading, that is, the dynamics may be viewed as anomalous diffusion, which in turn is related, and hence, the model can be directly applied to several complex systems ranging from biological fluids to electrolytic cells.
ISSN:2504-3110