Science Inventory

Environmental and Cost Benefits of Co-Digesting Food Waste at Wastewater Treatment Facilities - journal article

Citation:

Morelli, B., S. Cashman, Xin Ma, J. Turgeon, S. Arden, AND J. Garland. Environmental and Cost Benefits of Co-Digesting Food Waste at Wastewater Treatment Facilities - journal article. WATER SCIENCE AND TECHNOLOGY. IWA Publishing, London, Uk, 82(2):227-241, (2020). https://doi.org/10.2166/wst.2020.104

Impact/Purpose:

To explore the environmental impacts and life cycle cost of co-digestion energy recovery from food waste in medium scale wastewater treatment facility. The stakeholders that would be interested in this study and apply the results including local communities; utilities, OW; OWM; Regions; LCA practitioners, decision makers, academia; experts.

Description:

The wastewater industry is in the midst of a paradigm shift from focusing solely on treatment to incorporating concepts aimed at mitigating environmental impacts such as energy and nutrient recovery and water reuse. This study uses life cycle assessment and life cycle cost analysis to investigate the effect of expanding anaerobic digestion (AD) with a combined heat and power system on environmental and cost indicators at a mid-sized wastewater treatment facility (WWTF) in Massachusetts. Since 2014, Massachusetts has banned disposal of organic waste from commercial organizations producing more than one ton of these materials per week. The WWTF’s additional digester capacity allows the co-digestion of municipal solids with a food-based engineered bioslurry due to this ban. Study data were compiled for several AD feedstock quantity and performance scenarios, and compared to a baseline scenario representative of historic plant operations prior to co-digestion. Reductions in environmental impact are demonstrated for seven of eight environmental impacts including global climate change potential and cumulative energy demand. Eutrophication potential increases by 10 percent and 24 percent across assessed scenarios. Facility energy production increases dramatically with co-digestion, satisfying 100 percent of the WWTF’s thermal energy requirement and producing surplus electricity assuming full AD capacity utilization.