C-Ride Examples

Colloid-Facilitated Solute Transport (C-Ride) Module

Strongly sorbing chemicals (e.g., heavy metals, radionuclides, pharmaceuticals, pesticides, and explosives) in porous media are associated predominantly with the solid phase, which is commonly assumed to be stationary. However, recent field- and laboratory-scale observations have shown that in the presence of mobile colloidal particles (e.g., microbes, humic substances, clays and metal oxides), colloids can act as pollutant carriers and thus provide a rapid transport pathway for strongly sorbing contaminants. To address this problem, we have developed a two-dimensional numerical module C-Ride for the HYDRUS-1D and HYDRUS (2D/3D) software packages that incorporates mechanisms associated with colloid and Colloid-Facilitated Solute Transport (CFSTr) in variably-saturated porous media. The model accounts for transient variably-saturated water flow, and for both colloid and solute movement due to advection, diffusion, and dispersion, as well as for solute movement facilitated by colloid transport. The colloid transport module additionally considers the processes of attachment/detachment to/from the solid phase and straining. Various blocking and depth dependent functions can be used to modify the attachment and straining coefficients. The solute transport module uses the concept of two-site sorption to describe nonequilibrium adsorption-desorption reactions to the solid phase. The module further assumes that contaminants can be sorbed onto surfaces of both deposited and mobile colloids, fully accounting for the dynamics of colloid movement between different phases. Applications of the model are demonstrated using several selected test examples.

Note that the computational modules, examples, and manual for the 1D C-Ride module that you can download below are all still under development. We currently actively support mainly the recently developed C-Ride module which considers the same processes in 2D.

• Project Group: C-Ride Examples
• Description: Examples demonstrating the use of the C-Ride module simulating one-dimensional colloid-facilitated solute transport in variably-saturated porous media. Download the manual of the Colloid-Facilitated Solute Transport (corresponding 2D C-Ride module) Module in HYDRUS-1D (pdf).
• Availability: Download HYDRUS projects now (1.1 MB)
• Computational Modules: Download C-Ride computational modules now (1.1 MB)

No - no flow, SSF - steady-state flow, TF - transient flow

The C-Ride Manual:
Šimůnek, J., M. Šejna, and M. Th. van Genuchten, The C-Ride Module for HYDRUS-1D Simulating One-Dimensional Colloid-Facilitated Solute Transport in Variably-Saturated Porous Media, Version 1.0, PC Progress, Prague, Czech Republic, 43 pp., 2015.