Efficient and fast destruction of per- and polyfluoroalkyl substances (pfas) by high-frequency heating

Abstract

High-frequency heating (HFH) for the decontamination of soil containing per- and polyfluoroalkyl substances (PFAS) and aqueous film-forming foams (AFFFs) achieves ultra-fast degradation of short-chain PFAS, long-chain homologs, precursors, legacy PFAS, emerging PFAS in a matter of minutes. The concentrations of PFAS and the soil type have a negligible impact on degradation efficiency. Near-complete degradation occurs after one minute for perfluoroalkyl carboxylic acids and perfluoroalkyl ether carboxylic acids and two min for perfluoroalkanesulfonic acids. Polyfluoroalkyl precursors in AFFFs were found to degrade completely within one minute of HFH. No residual cationic, zwitterionic, anionic, or non-ionic intermediate products were detected following the treatment. Most of gaseous organofluorine products of PFAS at low-and-moderate temperatures disappeared when temperatures reached 890° C. Minimal loss of PFAS in water during the boiling process indicates a low risk of PFAS entering the atmosphere with the water vapor. HFH has potential as a remediation tool for PFAS-contaminated soils.

Dependencies are inferred from the claim text.