Impact of four surfactants on the uptake of per- and polyfluoroalkyl substances (PFAS) by red fescue grass.

Abstract

Per- and polyfluoroalkyl substances (PFAS) pose great risks to human health and the ecosystem, necessitating effective remediation strategies such as phytoremediation. Surfactants, due to their ability to increase the bioavailability of hydrophobic contaminants, are considered as potential agents to improve phytoremediation for PFAS. In this research, we explored the impact of four surfactants (sodium dodecyl sulfate (SDS), rhamnolipid, Triton X-100, and Glucopone 600 CS UP) on plant growth and the uptake of PFAS by red fescue over 110 days. The results showed that while surfactants at lower concentrations did not negatively affect plant growth, the highest dose (2,500 mg/kg) significantly reduced the dry weight of plant shoots. Although none of the four surfactants led to an increased overall removal efficiency of ∑PFAS by red fescue over 110 days, SDS did enhance the uptake of PFAS compounds with long carbon chain lengths. With SDS addition at 2,500 mg/kg, the average fold increases of long chain PFAS removal were 1.99 for perfluorooctanoic acid (PFOA), 2.44 for perfluorononanoic acid (PFNA), 2.11 for perfluorodecanoic acid (PFDA), 1.52 for perfluoroundecanoic acid (PFUnA), 1.88 for perfluorohexanesulphonic acid (PFHxS), and 2.97 for perfluorooctanesulfonic acid (PFOS). The research indicated that using surfactants, such as SDS at appropriate doses could improve phytoremediation effectiveness in mitigating long-chain PFAS, which is a known challenge in soil remediation.