PFAS mass loading question

A discussion forum for Hydrus-1D users.
Post Reply
Posts: 9
Joined: Mon Apr 20, 2020 12:09 am
Location: USA

PFAS mass loading question

Post by waterislife » Mon Nov 29, 2021 8:40 pm

I am simulating PFAS infiltration into the unsaturated zone. I know the mass of PFAS that was applied over time (quarterly pulses over decades) and the corresponding height of water associated with each mass loading to the ground surface. Currently, I have assigned concentration flux boundary conditions for the upper and lower boundaries and the initial conditions as liquid phase concentrations, as there is always precipitation concurrent to mass loading. Is this appropriate?

Posts: 5372
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: PFAS mass loading question

Post by Jirka » Mon Nov 29, 2021 10:39 pm

Yes, that’s the only way to get solute into the profile, i.e., with a boundary flux (using the Solute Flux BC).

The current Hydrus version does not consider sorption to the air-water interface, which I understand is an important process for PFAS fate and transport (see Silva et al., 2020). We are currently implementing this option into the next version of HYDRUS, which we hope to release around the New Year.


Silva, J. A. K., J. Šimůnek, and J. E. McCray, A modified HYDRUS model for simulating PFAS transport in the vadose zone, Water, 12(10), 2758, 24 p., doi: 10.3390/w12102758, 2020.

Post Reply