Sustained Hydrated Electron Production for Enhanced Reductive Defluorination of PFAS in Groundwater

Water Research, Journal Year: 2025, Volume and Issue: 279, P. 123401 - 123401

Published: Feb. 28, 2025

Hydrated electrons (eaq‒; ‒2.9 V) are effective at defluorinating per- and polyfluoroalkyl substances (PFAS), but production of eaq‒ often requires excess source chemicals, anoxic environment, harsh pH conditions. To improve the feasibility reductive process, we harnessed phenol as a chemical yielding four stoichiometrically utilized dithionite (DTN) to catalyze cycle for sustained yields. The added DTN not only scavenges dissolved oxygen, trap, also reductively transforms degradation product, p-benzoquinone, hydroquinone which yields more upon UV irradiation. In UV/phenol/DTN system, up 70 % defluorination PFOA solution was achieved while impact groundwater matrix minor on performance PFOA, PFOS GenX. Especially in acidic conditions, •H, conjugate acid eaq‒, is dominant radical decomposing three tested PFAS. Density functional theory calculations reveal hydrogen bonding van der Waals interactions between PFAS phenol, facilitating both decarboxylation fluorine elimination structures. combined experimental theoretical evidence demonstrated capability new method sustain matrix.

Language: Английский

Leading Techniques for Per- and Polyfluoroalkyl Substances (PFASs) Remediating in Water and Wastewater

Water, Journal Year: 2025, Volume and Issue: 17(9), P. 1319 - 1319

Published: April 28, 2025

Per- and polyfluoroalkyl substances (PFASs), a class of synthetic organic compounds since the 1940s, have become widespread persistent environmental pollutants. Due to their high chemical stability, bioaccumulation potential, extensive industrial household applications, PFASs drawn significant attention from researchers worldwide in recent years, while hot topic, publications are updated very quickly. Various remediation technologies, including adsorption, pyrolysis, biodegradation, advanced oxidation, been developed treated as leading techniques mitigate PFAS contamination. Other alternative foam fractionation, constructed wetland, piezoelectric ball milling. However, effectiveness these methods varies depending on reaction mechanisms, operational conditions, factors. This review provides comprehensive summary latest advancements removal strategies, highlighting advantages, limitations, potential synergies. Furthermore, future research directions technological developments discussed explore more efficient, sustainable, cost-effective solutions for remediation.

Language: Английский