Exposure of Juncus effusus to seven perfluoroalkyl acids: Uptake, accumulation and phytotoxicity

The extensive use of poly- and perfluoroalkyl substances (PFAS) has led to perfluoroalkyl acids (PFAAs) contamination in various environmental matrices. To remove PFAAs from contaminated water, this study investigated plant uptake of PFAAs by a native wetland plant species in the US, Juncus effusus. The results showed that J. effusus translocated selected PFAAs, including perfluoropentanoic acid (PFPA), perfluorobutanesulfonic acid (PFBS), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorohexanesulfonic acid (PFHxS), perfluorooctanoic acid (PFOA), and perfluorooctanesulfonic acid (PFOS). During the 21-day experimental period, the uptake of PFAAs increased with increasing PFAAs exposure concentration and time. PFOS was largely accumulated in the roots with limited upward translocation. PFAAs with shorter carbon chain length were taken up by J. effusus roots and tended to accumulate in plant shoots. The highest removal efficiency (11.4%) of spiked PFAAs by J. effusus was achieved when it was exposed to PFAAs at around 4.6 mg/L for 21 days. The exposure to PFAAs stimulated the antioxidative defense system in J. effusus shoots but inhibited the superoxide dismutase (SOD) and catalase (CAT) activities and damaged the antioxidative defense system in J. effusus roots. These results warrant further studies to evaluate J. effusus's long-term performance in a PFAAs contaminated environment.