Name

Treatment wetlands as nature-based solutions in managing emerging micropollutants: PFAS and beyond

Speakers

Dr Tao Lyu

Authors

Tao Lyu, Cranfield University, UK

Description

The performance of treatment wetlands (TWs), as a nature-based solution, in mitigating persistent per- and polyfluoroalkyl substances (PFAS) and their interactions with existing treatment flowsheets remain unclear. This study, for the first time, investigated PFAS removal in two UK full-scale surface flow TWs treating secondary effluents from domestic wastewater treatment plants. The systems demonstrated their capacities to safeguard natural water bodies by achieving discharge levels of the legacy PFOS (4-4.6 ng L⁻¹) and PFOA (1.79-3.27 ng L⁻¹) with removal efficiencies of 29%-38% and 15%-34%, respectively. Partitioning behaviour analysis revealed that sediment adsorption was the dominant removal pathway, achieving removal rates 16-61 times higher than plant uptake for PFOS and 1.8-6 times higher for PFOA. Sediment iron content, depth, and bulk density were positively correlated with PFAS sequestration, highlighting their importance in controlling PFAS mobility. Notably, a conventional mass balance analysis was challenged by the transformation of PFAS precursors into terminal compounds, including PFOS and PFOA, potentially inflating input concentrations and contributing to mass imbalance during treatment. While further research is necessary to address these complexities, the findings provide confidence in the use of TWs as scalable and eco-friendly solutions for mitigating PFAS pollution and offer valuable insights for optimising wetland design and operation to safeguard aquatic ecosystems.

Time

12:40 PM - 1:05 PM

Location Name

Room 3

Track

10:05 - 16:15 Micropollutants & Emerging Contaminants