Phytoremediation with Salix spp: A sustainable Approach to PFAS Remediation at Firefighting Training Sites

Per- and polyfluoroalkyl substances (PFAS) pollution has escalated into a significant environmental challenge, with firefighting training sites identified as one of the sources. The development of effective, sustainable, and cost-efficient methods to reduce or minimize the further environmental impact of PFAS to the surrounding is necessary. Salix spp. has been effective in reducing various pollutants, both organic and metallic, and may also be a solution for PFAS- contaminated firefighting training sites. The growth of three Salix spp. cultivars, Ester, Wilhelm, and Loden, was evaluated in a 6-week laboratory study. The aim was to assess the impact of PFAS-contaminated soil and irrigation water on plant development, and to investigate the uptake of PFAS into the plants by analysing the levels of PFAS in shoots and roots after completion of the study. The cultivars were grown in PFAS-contaminated soil originating from a firefighting training site in southern Sweden. The boxes with the cultivars were irrigated either with tap water or PFAS-contaminated groundwater. The experimental setup included also a control group, planted in uncontaminated soil (commercial potting soil) and watered with tap water. All three Salix cultivars exhibited a well-developed root system and shoot growth compared to the control. This study demonstrated that Salix spp. could grow in PFAS-contaminated environments and can take up PFAS from the soil. These findings suggest that Salix spp. is a promising candidate for phytoremediation at PFAS-impacted sites.