Researchers at Rice University have shown that PFAS-laden firefighting foam can be broken down in about 10 seconds using an arc welder, with the fluorine captured as silver fluoride, a reagent used in pharmaceutical chemistry. The method, published in Nature Chemical Engineering, converts a difficult waste stream into a useful product instead of just destroying the pollutant. The team tested real foam from a U.S. Army fire-suppression site and recovered about 90% of the fluorine as silver fluoride. The process recycles the silver over multiple runs without yield loss, and the authors estimate it uses 40-46% less energy and 72-83% lower operating cost than standard routes to silver fluoride. However, the largest batch so far is about 1 gram, and the cost and emissions figures are modeled, not measured at pilot scale. The authors also note that the quartz lining leaks some fluorine, and spent sorbents with other halogens still need testing.
