Electrochemical Oxidation for PFAS Destruction: A Municipal Drinking Water Utility Case Study

Electro-oxidation (EO) provides a method to mineralize Per- and Polyfluoroalkyl Substances (PFAS) compounds, eliminating them forever. Demonstration studies for destruction of PFAS have been successfully conducted on highly concentrated waste streams, such as AFFF and landfill leachate, but most drinking water treatment plants in the US will experience lower concentrations of PFAS contaminations. In this study, conducted at a water treatment plant on surface water with PFAS concentrations in the parts per trillion range, Reverse Osmosis (RO), Foam Fractionation (FF), and Ion Exchange were used as means to remove and concentrate PFAS followed by EO. Using a concentration process prior to the EO process reduces the liquid volume needing treatment and improves energy and destruction efficiency of EO by orders of magnitude thereby reducing overall costs. The study investigated destruction of PFAS on the RO concentrate, foamate, and IX brine regenerant, including sampling and analysis of byproduct formation and transformation of PFAS compounds from longer chains to shorter chains.