Chapter 18. Transport by Random Motion
Published Online: 8 JUN 2005
DOI: 10.1002/0471649643.ch18
Copyright © 2003 John Wiley & Sons, Inc. All rights reserved.
Book Title
Environmental Organic Chemistry
Additional Information
How to Cite
Schwarzenbach, R. P., Gschwend, P. M. and Imboden, D. M. (2005) Transport by Random Motion, in Environmental Organic Chemistry, John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/0471649643.ch18
Publication History
- Published Online: 8 JUN 2005
- Published Print: 23 AUG 2002
ISBN Information
Print ISBN: 9780471350538
Online ISBN: 9780471649649
- Summary
- Chapter
Keywords:
- Fick's Laws;
- molecular diffusivity;
- turbulent diffusion;
- transport in porous media
Summary
The chapter serves as the mathematical basis of Chapters 19 to 25 to describe random motion, as opposed to directed (advective) motion. The concepts of diffusion and Fick's First and Second Laws are introduced. Solutions of these equations in one to three dimensions are given for flat and spherical boundaries. As an important application at the molecular level, molecular diffusivities in gases (e.g., air), liquids (e.g., water), and porous media (e.g., sediments) are introduced. The chapter ends with a short preview on random motion at the macroscopic scale (turbulent diffusion and dispersion) as discussed later in the book.