Lessons Learned from the Testing, Design, and Installation of the First Foam-Fractionation + Electrochemical Oxidation Treatment System for PFAS Destruction

Abstract Description: The use of per- and poly-fluoroalkyl substances (PFAS) was once a mandated for vapor suppression in many metal plating and finishing facilities. Although such use has been discontinued for well over a decade, many metal finishing facilities continue to struggle with residual PFAS compounds in their process and wastewater streams. Faced with the need to provide effective treatment while also reducing operating cost, a metal finishing operation in the Grand Rapids, MI began work to evaluate and select an onsite treatment and destruction system to address PFAS at several of their existing facilities. Tasked with the need to develop an effective way to remove PFAS from its wastewater stream the team successfully developed its own in-house foam-fractionation process capable of achieving the Michigan Department of Environment, Great Lakes & Energy (EGLE) discharge limits for PFAS (<=16 ppt) and PFOA (<=7 ppt). Concentrated foamate from the foam-fractionation process was then passed to an electrochemical oxidation process onsite PFAS destruction. Pilot testing of the combined process was completed in early 2024 and confirmed that electrochemical oxidation process could easily achieve 3-log to 5-log destruction of both long and short chain PFAS compounds from influent concentrations as high as 73 mg/l. Based on the successful testing results, the site chose to install complete PFAS removal and electrochemical destruction processes at several of its existing facilities. Work on the first system commenced with installation of a temporary system to fine-tune overall system performance for the final full-scale system which is scheduled to be complete in mid 2025. This paper will provide an overview of the project from pilot testing through installation of the first commercial-scale foam-fractionation + electrochemical oxidation PFAS destruction system for metal finishing wastewater applications along with along with lessons-learned for future projects.