Phytoremediation potential for poly- and perfluoroalkyl substances (PFASs) using various plant species

Abstract: Poly- and perfluoroalkyl substances (PFASs) have unique chemical characteristics and are used in a wide variety of products. PFASs have been found in wild animals and humans and have shown adverse effects. Different remediation methods have been developed to remediate PFASs in the environment. Phytoremediation is one of the remediation methods with certain advantages, such as being low-cost, energy-efficient, less harmful, flexible and effective in removing PFAS. This study aims to evaluate the potential of plant uptake of 12 different PFAS from mustard (Brassica juncea), sunflower (Helianthus annuus) and industrial hemp (Cannabis sativa). In addition, the effect of amendments i.e., fertilizers, microbes, and the combination of fertilizers with microbes on the uptake of PFASs was evaluated. Pot experiments were performed in a greenhouse at SLU. Four different treatments with different amendments (fertilizer and microbial fertilizer) were applied to the plants in this experiment. The results indicated that PFASs were mostly transported and accumulated in the leaves, as opposed to the other plant compartments. Hemp had the highest levels of PFASs in the plant tissue (14.3 μg/plant) in comparison to sunflower (12.9 μg/plant) and mustard (8.3 μg/plant) in all control samples. Even though the total uptake of PFASs by mustard is the lowest, the PFAS concentration in mustard leaf is the highest (1.2 μg/g dry weight (dw)) among all plant compartments. The amendment with nutrient fertilizer and the amendment with microbe fertilizer decreased the PFAS concentration in the plant tissue, due to the sorption between PFASs in the soil and the fertilizer added. In conclusion, hemp seems a promising candidate for phytoremediation of PFAS contaminated soil.