Scientific leader: Eric Michel <eric.michel@inrae.fr> (INRAE, UMR EMMAH, Avignon).

The VSoil platform has been used to simulate the fate of persistent fluorinated pollutants (PFAS - per- and polyfluoroalkyl substances) in soils.

Details of the work carried out under this theme are presented below.

• Elisabeth Fries (PhD student from January 2021 to December 2023)

Elisabeth Fries (Gustave Eiffel University, Champs-sur-Marne) worked during her PhD on the transport and retention of fluorinated pollutants in soils using magnetic resonance imaging and computer simulations. She was supervised and funded by Gustave Eiffel University and INRAE. The experimentations were financed by ADEME through IPANEMA project.

Elisabeth used the official ColloidsTranspCDE model from VSoil platform to simulate the transport of fluorinated pollutants in a sand column with and without PFAS sorbtion. She calibrated the dispersivity, the porosity and the sorption paremeters using the Levenberg-Marquardt's algorithm (from minpack.lm R package) included in VSoil with combination of MRI experimental data of contaminant transport. This required to create a new output variable (named MRI signal) associated to the particles and colloids transport process. This variable was obtained from the concentration of PFAS in the soil profile calculated by the model.

The experimental MRI profiles were recorded as the average over time of several acquisitions. A new option in the parameter estimation routine in VSoil was added to average over time outputs of a model to mimic this acquisition procedure.