(CN) — A new technique could help solve two major problems at once: breaking down stubborn “forever chemicals” that pollute the environment, and recovering fluoride, a valuable element used in medicine and manufacturing.
Researchers at the University of Oxford, in a study published Monday in the journals Nature, outlines a method for destroying perfluoroalkyl and polyfluoroalkyl substances — also known as PFASs — while recovering the fluoride within them.
These human-made chemicals have been widely used since the 1940s in products like nonstick cookware, firefighting foam and textiles. Because of their strong chemical bonds, they don’t degrade easily and have built up in soil and water over decades, earning the nickname “forever chemicals.”
Existing methods for breaking down PFASs often fall short. According to researchers, they tend to produce smaller toxic byproducts or release fluoride in forms that can’t be recovered. That’s a problem, especially as fluorspar — the mineral used to produce industrial fluoride — is becoming harder to source and is now classified as critical by several countries.
According to Véronique Gouverneur, Oxford chemistry professor and a corresponding author of the study, the new method offers a more complete solution by destroying PFASs and recycling the fluoride for reuse.
“Under mechanochemical conditions, the phosphates salt triggers PFAS destruction,” she said in an email. “The destruction process produced fluoride and fluorophosphate ions, which were efficiently recovered and repurposed into high-value fluorinating reagents.”
The process involves combining Teflon, a common PFAS, with potassium phosphate salts in a steel jar and shaking the mixture at high speed — 35 times per second — for three hours. That mechanical energy helps break the carbon-fluorine bonds that make PFASs so persistent. The researchers found the method worked on several types of PFAS found in consumer products.
One of the key challenges, Gouverneur said, is the strength of the carbon–fluorine bond, which is one of the strongest in chemistry. But in this case, phosphate salts made the reaction more efficient and recoverable.
“The innovative introduction of phosphate for mechanochemical PFAS destruction offers a simple yet powerful solution to a longstanding chemical and environmental challenge,” she said.
Another benefit of the method is that the phosphate salts used to trigger the reaction can be recovered and reused, which makes the process more sustainable, researchers say.
That kind of circular chemistry, where materials are reused instead of discarded, could help reduce waste while supporting industries that rely on fluorine-based chemicals.
“It is estimated that the global reserve of fluorspar will last for only decades at the current consumption rate,” Gouverneur said in an email. “So, the recovery of fluoride from PFAS waste not only addresses the PFAS challenge but also contributes to sustainable fluorine chemistry by converting PFAS into valuable fluorochemicals.”
While the results are promising, researchers say more work is needed before the method can be widely adopted. That includes scaling up the process, assessing economic feasibility and evaluating its environmental impact over time.
“Achieving societal impact from academic research to address waste management is a complex endeavor,” Gouverneur said. “Important work remains before this technology can be used in industry.”