To address the long-term liability associated with chemical-impacted groundwater, the overall objective of this project is to demonstrate and validate a technology combination for complete on-site treatment and destruction of per- and polyfluoroalkyl substances (PFAS) in groundwater. Specifically, the project team will conduct a demonstration/validation of PFAS removal from impacted groundwater by combining Surface-Active Foam Fractionation (SAFF®) and the Annihilator^TM Supercritical Water Oxidation (SCWO) technologies. The project team will conduct this work at Wurtsmith Air Force Base (AFB) in Oscoda, Michigan.

This demonstration combines two innovative technologies, foam fractionation and SCWO, commercially deployed as SAFF® by Allonnia and Annihilator^TM by Battelle. SAFF®, invented by OPEC Systems, and specifically the SAFF®40 unit to be used for this project, comprises a train of foam fractionation stages that operate in a semi-batch mode.

The first stage (primary fractionator) ‘strips’ PFAS from the impacted feed using only air and produces a PFAS-depleted effluent that is free of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). The treated water is then pumped from the bottom of each aeration vessel and sent to the ‘clean’ water discharge. The primary foamate containing the PFAS comprises the feed to the second stage (secondary fractionation), which concentrates the PFAS further. If additional concentration is desired, the enriched secondary foamate, or super-concentrate, from the secondary unit can be fed through a third stage (tertiary fractionation) to produce a highly enriched PFAS hyperconcentrate. The super- or hyper-concentrate represents a low-volume, high-density PFAS matrix ideal for effective on-site destruction.

The on-site destruction will be achieved through Annihilator^TM, a commercial application of SCWO that leverages reactions that occur above the supercritical point of water in the presence of oxygen. In these conditions, the carbon-fluorine bond dissociation energy is overcome, and recalcitrant compounds such as PFAS are mineralized to products including carbon dioxide, water, hydrofluoric acid, and salts.

The demonstration/validation of PFAS removal from water will be performed through the first ever coupling of SAFF® and Annihilator^TM technologies for complete on-site treatment. Success will constitute the following:

1. PFAS removal and effluent concentration reduced to below regulatory limits for PFAS compounds during SAFF® primary treatment.
2. Concentration to >2000:1 during secondary and >200,000:1 during tertiary SAFF® treatment.
3. Demonstration of >99.99% on-site destruction of PFAS concentrate by SCWO for PFOS, PFOA and any other regulated PFAS compounds.
4. Cost effectiveness compared to granular activated carbon/ion exchange technology, including single-use and regenerable resins.

There are estimated to be more than 40,000 PFAS-impacted sites in the United States. This project will demonstrate that SAFF® and Annihilator™ represent a tremendous improvement to existing technologies available for PFAS treatment, in terms of effectiveness, cost, and sustainability. These combined on-site technologies will reduce PFAS concentrations in impacted water by first separating and concentrating, and then destroying PFAS compounds. No PFAS-impacted media will leave the site. Results from the work are expected to provide an improved capability to cost-effectively remediate groundwater sites. (Anticipated Project Completion - 2025)