Work

Full-scale Hazardous Waste Incineration of PFAS in Fluorotelomer-Based Aqueous Film-Forming Foam

Year: 2026

Type: preprint

Abstract: In the absence of full-scale incineration studies into the impacts of temperature on thermal destruction of per- and polyfluoroalkyl substances (PFAS), globally evolving regulatory guidelines have been inconsistent. In this study, we incinerated a fluorotelomerization-based aqueous film-forming foam (AFFF) concentrate at different temperatures and feed rates of up to 1500 kg/h in one of the largest hazardous waste incinerators in the world. At secondary combustion chamber temperatures as low as 950 °C and 2 seconds gas residence time, the destruction and removal efficiency for the main AFFF component 6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB, a.k.a. Capstone B) exceeded 99.999999% at the highest AFFF feed rate. Non-polar volatile fluorinated compounds targeted by Other Test Method 50 (OTM-50) were below method detection limits, while PFAS concentrations in ashes and scrubber waters were practically indistinguishable from baseline conditions when no fluorine-containing waste was incinerated. PFAS stack emissions into the atmosphere during AFFF treatment were substantially lower than volatile PFAS emissions from a typical landfill. Quantum chemical modeling suggested that a similar treatment efficiency may be expected for perfluorooctane sulfonic acid (PFOS)-based electrochemical fluorination foams. The findings of our study suggest that hazardous waste incineration may be effective at temperatures well below the 1100 °C required by some current regulations, minimizing fuel consumption, equipment wear, and undesirable side reactions during thermal PFAS destruction.

Source: ChemRxiv

DOI: 10.26434/chemrxiv.15008894/v1