Safeguarding Soil with PLANTS: Exploring Phytoremediation for PFAS Cleanup

Activities 2025:

Preliminary results from the PFAS exposure experiments with nettle (T1.2), conducted in pots with 1% and 3% organic carbon, indicate that the organic‑carbon content does not influence the relative PFAS uptake by the plants. Compared to the initial soil concentrations, 0.1–23.5% of the PFAS was recovered in the plant biomass. The highest relative uptake occurred at the lowest soil concentrations, suggesting a relatively greater phytoremediation potential of nettle at low PFAS levels. A similar experiment with varying percentages of fine soil fraction was recently completed (December 2025), and analyses are currently ongoing. For the hemp pot trials, no PFAS analysis data are yet available.

At Blokkersdijk (T2.2), reed samples collected in February and June 2025 were analysed for PFAS. No consistent differences were found between the two seasons, nor between plots with different mowing histories. Most bioaccumulation factors (BAF) are below 1, indicating limited potential for phytostabilisation. The translocation factor (TF) strongly depends on PFAS chain length, particularly for the carboxylic acids. Short-chain PFAS, such as PFBA and PFPeA, often show TF values >1, while longer chains typically have TF <1. This points to a greater phytoextraction potential for short-chain PFAS.

In the agricultural area, a hemp phytoremediation trial was conducted in 2025 (7×10 m test plots) to assess the effect of different nitrogen fertilisation regimes and timed sampling of various tissues (stem, leaf, root) (t25, t50, t75, t100). Samples were collected and prepared for analysis. Only preliminary PFAS results are currently available; triplicate analyses for each time point have not yet been completed. Full PFAS analyses are scheduled to be finalised by UA in May 2026.

In the first project year, an approach and methodology were also developed for a stakeholder survey. Although initially planned for the first six months of the project, stakeholder interviews will instead be conducted during the first months of project year 2 (M13–M18).