Related Experiment Video
Updated: Jul 12, 2026

The Diffusion of Passive Tracers in Laminar Shear Flow
Published on: May 1, 2018
Intragranular diffusion: an important mechanism influencing solute transport in clastic aquifers?
Intragranular porosity in aquifer sand is greater than previously measured, revealing more reaction sites. This finding necessitates including diffusion expressions in transport models for radioactive and toxic waste simulation.
Area of Science:
- Geology
- Environmental Science
- Hydrogeology
Background:
- Standard laboratory tests underestimate intragranular porosity in aquifer sand.
- Aquifer properties significantly influence solute transport and contaminant fate.
Purpose of the Study:
- To accurately quantify intragranular porosity in sand-size aquifer material.
- To assess the impact of this porosity on solute transport and reaction kinetics.
Main Methods:
- Scanning electron microscopy (SEM)
- Mercury injection porosimetry
- Epifluorescence microscopy
- Laboratory and field tracer tests
Main Results:
- Intragranular porosity and reaction sites are significantly greater than indicated by standard methods.
- Tracer tests revealed solute nonequilibrium, consistent with diffusion into and exchange within grain interiors.
- Observed phenomena necessitate a revised understanding of solute transport in porous media.
Conclusions:
- Standard measurement techniques fail to capture the full extent of porosity and reaction sites in aquifer sands.
- Diffusion into grain interiors is a critical process influencing solute transport, especially for reactive contaminants.
- Transport models require updated diffusion expressions for accurate simulation of contaminant migration, particularly for radioactive and toxic wastes.
More Related Videos
07:57An Experimental and Finite Element Protocol to Investigate the Transport of Neutral and Charged Solutes across Articular Cartilage
Published on: April 23, 2017
12:03Two-Dimensional Visualization and Quantification of Labile, Inorganic Plant Nutrients and Contaminants in Soil
Published on: September 1, 2020
Related Concept Videos
Transcellular Transport of Solutes
Facilitated Transport
Facilitated Transport
Drug Absorption Mechanism: Passive Membrane Transport
Formation of Concentrated Urine
Facilitated Diffusion
In this process, substrates such as organic compounds and ions interact with a transporter on one side, triggering conformational changes in proteins that enable...