PFAS Treatment Results of AFFF Wastewater

PFAS compounds are extremely stable, making complete destruction difficult.

• Incineration is effective but controversial (and often banned).
• Other conventional treatment methods (granular activated carbon (GAC), ion-exchange (IX) resins, foam fractionation, and membrane separation) separate PFAS from the water stream, leaving behind PFAS-laden media or a concentrated PFAS stream that requires further treatment or disposal.

Electrochemical Destruction

Offers alternative to conventional approaches.
• Uses electricity and advanced materials to achieve complete destruction of PFAS from contaminated water.
• Can be used independently or integrated with separation/concentration processes.

Typical features of a containerized system

PFAS Testing

Axine performed tests on various wastewater streams at the lab scale.

Industrial wastewater:
• Manufacturing processes
• Landfill leachate
• AFFF (Aqueous film-forming foam)
• Foam fractionation concentrate

Synthetic wastewater:
• Containing a mixture of six PFAS compounds (PFUnA, PFOS, PFOA, PFHpA, PFHxA, PFBA)
• At two levels of starting concentrations: ~10 µg/L each and ~2,000 µg/L each

250 USG Lab Test System

Results

Actual Industrial Wastewater
The industrial wastewater streams tested demonstrate the electrochemical destruction technology’s ability to achieve multi-log PFAS removal on streams with a wide range of starting concentrations, with the manufacturing waste stream at the high end and the landfill leachate at the low end.

TOP assay results also suggested the PFAS destruction process did not create precursors that may cause issues downstream.

Synthetic Wastewater Streams
The synthetic wastewater streams tested demonstrate the ability to treat PFAS with alkyl chain lengths ranging from C4 to C11 and at different influent concentration ranges. In particular, the test at high influent concentration (~12 mg/L total PFAS) showed that shorter chain PFAS by-products formed during destruction of long chain PFAS were ultimately destroyed at the end of treatment. In addition, anion analysis showed that most of the fluorine from the PFAS became fluoride ions.