Regeneration of PFAS-laden granular activated carbon by modified supercritical CO₂ extraction.

ABSTRACT: Granular activated carbon (GAC) is widely used to treat contaminated per- and polyfluoroalkyl substances (PFAS) waste streams, resulting in the accumulation of large quantities of spent GAC that need to be landfilled or regenerated. A novel modified supercritical CO₂ (scCO₂) extraction for regeneration of spent GAC is developed. With the addition of organic solvents and acid modifiers, the procedure yielded >99% perfluorooctanoic acid (PFOA) desorption after a 60-min treatment in a continuous flow reactor. The mild extraction conditions at T ∼100 °C do not trigger the formation of volatile organic fluorine or changes in GAC sorbent properties. Mechanistically, the high miscibility of co-solvent/scCO₂ eliminates diffusion transport limitations, enabling rapi

SUBMITTER: Didenko T 

PROVIDER: S-EPMC12149862 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature