Poly- and per-fluoroalkyl substances (PFAS) are present in thousands of consumer products, and their use in fire-suppressing aqueous film-forming foams has been a major source of groundwater pollution. Such foams form an aqueous film around burning gasoline and other flammable liquids, which quickly deprives the fire of oxygen and extinguishes it.

The U.S. Department of Defense has determined that 574 of 715 military sites surveyed for PFAS releases require further investigations or cleanups as required by federal law. Remediation has become more urgent with the recent imposition by the U.S. Environmental Protection Agency of a new rule requiring water utilities to reduce contamination if levels exceeded 4 ppt for certain PFAS compounds.

A new strategy to clean up these “forever chemicals” has been devised by researchers from Clarkson University and the University of California Riverside. The decontamination approach described in Nature Water treats heavily contaminated water with ultra-violet light, sulfite and electrochemical oxidation. The method was demonstrated to achieve near-complete destruction of PFAS in water samples contaminated by the foams.

Designed to process heavily contaminated water used to flush out tanks, hoses and other firefighting equipment, the method also can be applied to treat leftover containers of PFAS-containing foams as well as polluted groundwater. An added benefit is that treatment reactions occur at room temperature, eliminating the need for additional heat or high pressure to stimulate the process.