O. Coronell, F.A. Leibfarth, A.S. Gorzalski
UNC Chapel Hill,
United States
Summary:
Per and polyfluoroalkyl substances (PFAS) are a large, persistent class of contaminants that are widespread in the environment and present in numerous industrial waste streams. As regulations in the United States and worldwide tighten, the need for effective, scalable PFAS filtration technologies has become urgent. Existing sorbents suffer from low capacity and poor selectivity—especially for short chain PFAS—leading to frequent replacement and high operating costs. We have developed a regenerable, specialty granular resin that employs novel chemistries designed to capture PFAS efficiently. Bench and pilot scale performance tests reveal clear advantages over leading commercial ion exchange resins (IERs). When used as a single use sorbent, our resin consistently achieved substantially longer bed volumes to breakthrough for ultra short chain PFAS (e.g., 30-40 % longer for PFPrA at pilot scale) and comparable or greater breakthrough volumes for long chain PFAS such as PFOA. Unlike commercial IERs, which exhibited “PFAS peaking”—effluent concentrations exceeding influent concentrations due to displacement by competing sorbates—our resin showed no such effect, removing up to five times more ultra short chain PFAS per mass of resin by the end of the pilot run. In regenerable mode, brine based regeneration at bench-scale enabled the resin to treat up to four times more bed volumes before long chain PFAS (e.g., PFOA) breakthrough compared with a single use benchmark IER. These results demonstrate that the novel resin can outperform commercial IERs both as a single use and as a regenerable sorbent, with the latter mode delivering the greatest cost and sustainability benefits for end users.