21 Jul 2026

Demonstration Validation of Air Supercritical Water Oxidation (AirSCWO 6) PFAS Destruction: Aqueous Film-Forming Foam Treatment by 374Water AirSCWO Technology

Abstract: The Department of Defense (DoD) faces significant environmental challenges regarding the disposal of legacy aqueous film-forming foam (AFFF) containing persistent PFAS. This project, led by the US Army Engineer Re-search and Development Center (ERDC), evaluates the performance of the 374Water AirSCWO™ 6 system in destroying PFAS within AFFF. During the demonstration, 100 gal. of AFFF were treated, successfully meeting US EPA maximum contaminant levels (MCLs) for PFAS in the liquid effluent. The system achieved a destruction removal efficiency of 99.9993% for total PFAS as analyzed via the total oxidizable precursor (TOP) Assay (42 PFAS). Stack emissions remained below 500 g/h for vola-tile fluorinated compounds as measured by Other Test Method (OTM)–50. While the demister condensate exceeded US EPA PFAS MCLs, the total volume was negligible at less than 0.5 L. Energy efficiency analysis showed a consumption of 1.15 MWh per cubic meter of AFFF per order of magnitude of 42 PFAS destroyed and 12.9 kWh per gram of PFAS destroyed. Treatment costs varied and may range from $47 to $238 per gallon of AFFF. These results demonstrate the effectiveness of super-critical water oxidation technology for a safer disposal of legacy AFFF concentrates.

20 Feb 2026

Demonstration Validation of Industrial Supercritical Water Oxidation (iSCWO) PFAS Destruction Technology: Aqueous Film-Forming Foam Treatment by General Atomics (GA) iSCWO System

Abstract: The Department of Defense (DoD) is confronted with a pressing environmental challenge concerning legacy aqueous film-forming foam (AFFF) concentrate, historically used in firefighting activities. Legacy AFFF contains PFAS, which are identified as persistent environmental contaminants associated with adverse health effects. Considering increasing environmental regulations and concerns regarding human health impacts, the DoD needs to properly destroy legacy AFFF. The US Army Engineer Research and Development Center (ERDC) led a project focused on the demonstration and validation of technologies for the destruction of PFAS in AFFF. Results are presented for the treatment of 100 gal. of AFFF using the General Atomics industrial Supercritical Water Oxidation system. The demonstration showed destruction removal efficiencies (DREs) for total PFAS analyzed via total oxidizable precursor (TOP) assay (S24 PFAS), ranging from 98.5% to 99.9991%. No volatile fluorinated compounds were detected in the stack emissions as analyzed via Other Test Method 50; however, up to 6,000 ppt S51 PFAS as analyzed via TOP assay was detected in demister effluent. The energy consumed per cubic meter of AFFF and order of magnitude S24 PFAS destroyed ranged from 2 to 24 MWh, while the energy consumed per gram of S24 PFAS destroyed ranged from 0.046 to 48 MWh.