Mitigation Methods for Difficult-to-Treat PFAS in Drinking Water - ABSTRACT Per- and polyfluoroalkyl substances (PFAS) contamination in drinking remains a major environmental and public health issue, as these persistent pollutants resist natural degradation, accumulate in water supplies, and pose long-term health risks. As a result, the Environmental Protection Agency (EPA) has set enforceable Maximum Contaminant Levels (MCLs) for per- and polyfluoroalkyl substances (PFAS) in drinking water at 4.0 parts per trillion (ppt) for PFOA and PFOS. Metrics Water Catalyst (MWC) holds the exclusive license from Arizona State University (ASU) for a novel two- stage treatment process that couples catalytic defluorination with biological mineralization for complete PFAS destruction. ASU selected MWC as the licensee based on our proven engineering capabilities and ability to translate laboratory advances into deployable technologies. Bench-scale experiments at ASU Biodesign Institute have demonstrated effluent concentrations below EPA’s proposed maximum contaminant levels for PFOA and PFOS in drinking water. This Phase I project will address the required engineering efforts in membrane reactor material selection and construction methods, a critical step toward developing durable, field- deployable treatment systems for municipal use. Specific Aims: (1) Establish a scalable membrane manufacturing method for both reactors, including substrate selection, catalyst-film application (MCfR), surface preparation (MBfR), and documented SOPs with QC checks (yield, bubble-point/pressure-hold, gas flux/kLa, film loading/adhesion). (2) Verify mechanical and chemical durability under plant-like stress—pressure and temperature cycling, representative drinking-water chemistry (pH, alkalinity, hardness, NOM), and clean-in-place (CIP)—while maintaining integrity and gas- transfer performance within preset acceptance limits. (3) Optimize module geometry—packing density, fiber dimensions, flow path, and header/housing design—to increase specific surface area and gas-transfer coefficients at acceptable pressure drop and fouling risk, and to fit standard sanitary housings. Research Design and Methods: We will fabricate pilot lots of membranes and sub-scale modules; implement SOP-driven QC; run pre/post stress testing with integrity, flux/kLa, adhesion, and ΔP endpoints; and execute a structured geometry design-of-experiments. Deliverables include manufacturing SOPs and a QC plan, durability data packs, optimized drawings/BOM, and vendor-informed manufacturability recommendations (e.g., suggested processes, tolerances, and design improvements) suitable for future scale-up. Expected Outcome and Impact: A manufacturable, stress-tolerant, geometry-optimized membrane platform that de-risks Phase II pilot builds of destruction-based PFAS treatment and advances a practical route to lowering PFAS exposure at the tap.