Karen Johannesson

[Karen Johannesson]

I am just wondering if there is a way to restrict the location of where I can apply a surface complexation model along a groundwater flow path in X1t. Specifically, if I am trying to model reactive transport along a 100 km flow path, but only want to have the surface database FeOH.sdat apply along the first half of the 100 km flow path.

[Jia Wang]

Hello Karen,

There's no way to selectively apply datasets to sections of a domain. If  you want to set minerals in the system for just surface complexation reactions, you can set the mineral as a kinetic mineral and assign a zero kinetic rate constant. This zero reaction rate effectively sets them as inert minerals to provide a surface for complexation reactions and simple sorption. You can vary quantities of kinetic minerals throughout the domain such that they are absent in the last 50 meters of your domain. For more information on properties to vary within the domain or simulation, please see the Appendix: Heterogeneity chapter in the GWB Transport Modeling User's Guide.

Hope this helps,
Jia Wang
Aqueous Solutions LLC

 

[Karen Johannesson]

Hi Jia,

Thanks so much. This is very helpful and I think it will solve this question I have been wondering about recently.

Best wishes,

Karen

[Jia Wang]

Hello Karen,

Glad to hear that was helpful. Hope the rest of your project goes smoothly.

Best regards,
Jia

[Karen Johannesson]

Hi Jia,

I think I understood your previous helpful input. I am attaching an example script of what I think you were instructing me to try. This example script calls up goethite as the adsorbing mineral, but only allows for it to be implemented along the initial portion of the flow path. I know that after that radial distance, the aquifer sediments seem to have largely been stripped of their Fe(III) oxide coatings owing to microbial reduction (in part). I am wondering if I set up the kinetic Goethite correctly. I set a rate constant of 0, and then state that the Goethite is available along the initial 26% (or there abouts) length of the flow path.

Best wishes,

Karen

Example script.x1t

[Jia Wang]

Hello Karen,

The Goethite seems to be set up correctly. You can perform a Go -> Initial run and then verify the percentage of Goethite along the domain quickly by plotting Mineral (Goethite) volume% vs X position.

Best regards,
Jia

[Karen Johannesson]

Thanks Jia!

[Jia Wang]

You're welcome Karen. I hope the rest of your project goes smoothly.