Leveraging wastewater resource recovery to reduce landfill organic loading: Process modeling, environmental, and economic impact assessment

Food waste (FW) disposal remains a major sustainability issue in the U.S., with 38 % of the 96.8 million metric tons annually being landfilled. This study evaluates the benefits of diverting landfilled FW to wastewater resource recovery facilities (WRRFs) for valorization. Using U.S. county-level data, we conducted a static material flow analysis (MFA) and life cycle assessments for three (3) scenarios: FW landfilling, valorization at a conventional activated sludge (CAS) WRRF, and an anaerobic membrane bioreactor (AnMBR) WRRF with reverse osmosis (RO). Results show that landfilling produced the highest global warming potential (58.2 kg CO₂-eq/ton FW), whereas WRRF FW valorization pathways achieved net-negative emissions. Economic analysis indicated that WRRF valorization remained feasible even when tipping fees were 25 % below landfill rates, with net lifecycle profits of $2.45/ton FW (CAS) and $2.33/ton FW (AnMBR). Resource recovery, although modest, included 0.19 kg/day of struvite and 129 kWh/day for CAS, and 6.1 kg/day of struvite and 116.8 kWh/day for AnMBR. Energy return on investment (EROI) reached 18.8 % for CAS and 16.7 % for AnMBR, while phosphorus recovery was substantially higher in AnMBR (70.4 %) compared to CAS (7.9 %). This study presents a translatable framework integrating full-scale WRRF modeling with environmental and economic metrics to support a circular economy. To enhance viability, the study also recommends adopting supportive policy instruments—including optimized tipping fee structures, green financing mechanisms, and public–private partnerships—to drive operational efficiency. Collectively, these strategies can reinforce the financial resilience of WRRFs while positioning them as key enablers in accelerating urban circular bioeconomy transitions.