PHYTOREMEDIATION OF PER- AND POLYFLUOROALKYL SUBSTANCES (PFAS): MECHANISMS OF UPTAKE, TRANSLOCATION, AND TRANSFORMATION

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are highly persistent environmental pollutants with widespread contamination in soil and water. Phytoremediation, a sustainable and cost-effective approach using plants to mitigate PFAS contamination, has emerged as a promising treatment option. Phytoremediation mechanisms that might be involved include but are not limited to phytofiltration, phytoaccumulation or phytoextraction, phytostabilization, phytovolatilization, and phytodegradation. PFAS uptake in plants occurs primarily through root absorption from contaminated soil or water, influenced by the physicochemical properties of the PFAS molecules, plant species, and soil conditions. Long-chain PFAS exhibit lower mobility due to stronger interactions with soil organic matter, whereas plant roots more readily absorb short-chain PFAS. Once inside the plant, PFAS translocation to aerial tissues is driven by transpiration, with translocation factors varying significantly across plant species. Plants with high transpiration rates and developed vascular systems tend to accumulate more PFAS in their aerial biomass. The transformation of PFAS in plants remains an area of ongoing research. Omics-based approaches, including transcriptomics and proteomics, have provided insights into molecular responses to PFAS exposure, revealing oxidative stress responses, alterations in metabolic pathways, and potential enzymatic degradation mechanisms. While evidence suggests limited biotransformation of PFAS in plant tissues, the role of microbial communities in the rhizosphere may enhance PFAS degradation. To optimize phytoremediation strategies, future research should focus on identifying hyperaccumulator species, engineering plant-microbe interactions, and evaluating biomass disposal methods to prevent secondary contamination. This paper highlights the potential of phytoremediation as an environmentally friendly solution for PFAS-contaminated sites while addressing critical challenges in its implementation.