Challenge

Historic PFAS contamination in a Michigan industrial facility required a pump-and-treat solution for PFAS remediation of site groundwater. Perfluorooctane sulfonate (PFOS) concentrations averaged 1650 ng/L, exceeding local POTW limits of 28 ng/L. ECT2 targeted the following goals:

  • Treat PFOS in pumped water to <28 ng/L
  • Concentrate PFAS in foamate stream >1000x

Additionally, ECT2 teamed up with Enspired Solutions® to deploy their PFASigator™ technology for destruction of the PFOS-concentrated foamate.

Solution

ECT2’s FOAM-X™ pilot skid, designed to eat flows between 2-5 gallons per minute (GPM) using foam fractionation, was deployed to site for PFAS treatment. The FOAM-X pilot skid foam fractionator uses specifically designed air injection to generate a foamy layer, “foamate”, to removes PFAS from target streams and concentrates for destruction or disposal. A two-stage foam fractionation strategy was employed on-site that could simulate a full-scale continuous flow treatment. ECT2 evaluated multiple operational parameters, including FF-Boost chemical additives, system flow rate and fractionation air injection rates to optimize system performance for both PFOS removal as well as PFAS-waste volume minimization. Foamate produced during the pilot was fed to Enspired Solutions®’ PFASigator pilot unit, co-located on-site. The PFASigator uses photo-activated reductive fluorination (PRD) to destroy PFAS on-site, in a safe and cost-effective manner. Destruct effluent was returned to the head of the FOAM-X treatment system, completing a zero-waste treatment/destruction loop.

Results

This process successfully demonstrated a zero-waste PFAS treatment pairing FOAM-X foam fractionation with foamate waste destruction by Enspired Solution®’s PFASigator.

  • PFOS successfully treated to non-detect by the FOAM-X system
  • PFASigator destruction of concentrated PFOS in excess of 99.7% of mass
  • No PFAS waste requiring disposal generated during treatment

ECT2 treated approximately 43,232 gallons of PFAS-impacted water and demonstrated PFOS bulk removal in excess of >99.8% removal by mass. Additionally, this project achieved PFOS concentrations below the PFOS discharge limit of 28 ng/L in single state and non-detect in second stage. By utilizing this process, the project averaged a 1300x concentration factor, minimizing the waste volume that would require destruction.