Eco-FAST: Decision-Making Framework for Pathways of Food Waste Disposal and Recycle

Status: Ongoing

Funding Agency: New Jersey Department of Environmental Protection (NJDEP)

Abstract:

Food waste (FW) is the most frequently landfilled and incinerated material in the United States. Its disposal contributes to greenhouse gas emissions, groundwater contamination, and health burdens in overburdened communities. On-site aerobic biodigesters are increasingly marketed to large generators of FW as a convenient pre-processing technology. These units liquefy FW within 24 hours and discharge effluent to the sanitary sewer, thereby shifting organic loading from solid waste systems to water resource recovery facilities (WRRFs). However, there is limited independent data on how energy-rich these effluents are and whether they should be viewed as high-strength wastes that can support resource recovery rather than simply additional load on WRRFs.

This study characterizes biodigester effluents derived from representative FW mixtures and links the experimental results to an AI-enabled decision framework for FW management. Laboratory-prepared FW was formulated from high-loss commodities identified in USDA loss-adjusted food availability data, with separate fruit and vegetable waste (FVW), meat waste (MW), and mixed blends. Selected mixtures underwent aerobic digestion in bench-scale reactors that mimic biodigesters. The resulting effluents were characterized for total and volatile solids and then processed in batch HTL tests to quantify biocrude yields and in biochemical methane potential tests to quantify specific methane production.

The experimental data parameterizes Eco-FAST (Ecological Impact of Food wASTe Recycle Effluent), a web-based decision framework now under development for New Jersey regulators and utilities. Eco-FAST uses superstructure optimization and process-systems models to compare conventional FW pathways (landfill, incineration, direct AD) with scenarios that include biodigesters followed by energy recovery from effluent.

Preliminary results show that aerobic digestion does not eliminate the energy value of FW. Biodigester effluents retain substantial volatile solids and can generate both biocrude and methane, although yields and reaction rates are lower than those from raw FW. Integrating these measurements into Eco-FAST allows WRRFs and state agencies to quantitatively compare management options and determine when biodigester effluent should be managed primarily as a high-strength waste to be controlled and when it can instead be intentionally routed to HTL or AD for energy recovery.

Investigators: Dr. Jagadish Torlapati, PhD., Dr. Kirti Yenki, PhD.

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