This joint proposal brings together the University of Southern California and FEED Resource Recovery (FEED) to collaboratively develop strategies to optimize decentralized anaerobic membrane bioreactor treatment of food waste. With new diversion rules for food waste in California taking effect 2020, decentralized anaerobic membrane bioreactor systems could benefit the food processing industries and other food waste producers to effectively manage their waste with recovery of renewable energy. Life cost analysis and life cycle cost analysis will provide valuable information on economic and environmental benefits, which could be helpful for policy makers, investors and food waste producers to adopt the technology.
The focus of this project is to divert food waste from landfills to wastewater treatment plants or decentralized anaerobic digestion facilities where it can be converted to energy. There has been substantial research effort on anaerobic digestion of various waste streams, including food waste. However, anaerobic membrane bioreactors are still an emerging technology with few full-scale systems in operation worldwide. They are particularly attractive for decentralized food waste treatment given their smaller footprint, increased energy recovery, and higher quality effluent relative to conventional digestion. Food waste management has unique challenges relative to sewage sludge digestion. For example, food waste characteristics vary seasonally (e.g. corn or pumpkin season) which can be detrimental to process performance due to fluctuations in organic loading, toxicity, and other concerns. Further, components of food waste such as inorganic particles can be problematic for polymeric membrane integrity. FEED has experienced these issues first-hand. The PIs will evaluate strategies to optimize anaerobic membrane bioreactor treatment of food waste such as two-phase anaerobic membrane bioreactor treatment, co-digestion with fats, oil, and grease, and ceramic flat-sheet membranes. Pending positive results from bench-scale studies, the project team plans to evaluate two-phase treatment at the full-scale. The use of cutting-edge molecular microbiological tools on bench- and full-scale systems will advance our broader understanding of anaerobic food waste treatment at a mechanistic level. Life cycle analysis and life cycle cost analysis of anaerobic membrane bioreactors will provide valuable information to compare the economic and environmental merits of anaerobic membrane bioreactor in comparison to other food waste management method. Development of sustainability assessment tools will highlight economic and environmental opportunities for FEED and the solid waste industry. The proposed industry-university collaboration enables comprehensive evaluation of decentralized anaerobic food waste treatment through bench- and full-scale studies, use of advanced molecular microbiological analyses, and development of sustainability assessment tools. One Ph.D. student will be funded by this project and work both at USC and FEED over the project duration. In addition, an outreach activity (seminar and tour of FEED facility) for Carson High School students in the Environmental Science, Engineering, and Technology program is proposed to expose high school students to graduate studies in engineering and career paths in industry.
