Pilot-scale demonstration of advanced wastewater treatment for direct potable water reuse for beer production

To foster public trust in water reuse and develop solutions for future water scarcity, the B-WaterSmart project piloted water reclamation for artisanal beer production, providing scientific evidence on the safety of direct potable reuse (DPR) in industry. The demonstration took place at the Beirolas Water Resource Recovery Facility in Portugal, where four advanced treatment technologies were tested: ultrafiltration (UF), ozonation (O3), biologically active granular activated carbon (BAC) filtration, and reverse osmosis (RO). Four RO-based reclamation schemes were continuously piloted (24/7) to assess water quality and operational performance: (1) UF + O3 + RO, (2) UF + RO, (3) UF + O3 + BAC + RO, and (4) O3 + BAC + RO. Water quality was monitored weekly for E. coli, organic matter and nutrients, and, once per scheme, for trace compounds, including 54 pharmaceutical compounds (PhCs), 2 hormones, oxidation by-products (N-Nitrosodimethylamine (NDMA), bromate, chlorate, 4 trihalomethanes (THMs), 9 haloacetic acids (HAAs)), 20 per-and polyfluoroalkyl substances (PFAS), 10 alkyl-phenols, and toxicity (Daphnia magna, Vibrio fischeri). EU Drinking Water Directive 2020 parameters and pathogen indicators (Clostridium perfringens, enteric viruses, protozoa) were also assessed. All treatment schemes produced water meeting EU and Portuguese drinking water standards, with no pathogen indicators and with trace contaminants below quantification limits (PFAS G 2 ng/L, 5 HAAs G 1 mu g/L, bromate G 3 ng/L, PhCs G 0.3 mu g/L) or below international regulations or guidelines (total THMs G 2 mu g/L, NDMA G 8 ng/L). Operational monitoring showed lower energy demand for the UF + RO scheme, corresponding to 1.0 kWh/m3. Furthermore, a craft beer company used the produced water to brew 1000 L of beer, which received a positive organoleptic evaluation from its producer.