By SLOANE GRINSPOON
A group of Cornell students has collaborated with the Ithaca Area Wastewater Treatment Facility to research ways to use food waste from campus dining halls as an energy source for the sewage plant.
The Cornell University Sustainable Design Anaerobic Digestion Team, a group that consists of four Cornell undergraduates, has been working with the water treatment facility for the past year by assessing the feasability of proposed plans for a large-scale anaerobic co-digestion operation, according to Adam Pranda ’14, a CUSD Anaerobic Digestion team member.
According to Pranda and Marina Shumakovich ’14, another member of the team, anaerobic co-digestion is a process in which wastewater and food waste are put into a bioreactor that contains microorganisms. Facilities with these reactors can then harness the resultant methane and use it as energy sources.
Pranda said the end goal of the new equipment installation is to be able to harness enough potential methane gas from food waste and wastewater to power the facilities’ heating and power systems.
The water treatment facility is currently undergoing an $8-million energy performance upgrade, which includes improved equipment that can convert food and water waste into energy, according to the facility’s website.
The CUSD team examined five different case studies to prove the past successes of anaerobic co-digestion in other facilities, Pranda said.
“The Ithaca Wastewater Treatment Facility was mainly interested in the information we gathered from case studies regarding the success of co-digestion at other facilities and how these facilities utilized any excess energy, such as putting it back into the electricity grid,” Pranda said.
The team then conducted its own feasibility study, using a tool developed by the Environmental Protection Agency — the CoEAT tool — to conduct a cost-benefit analysis, according to Pranda.
“The tool is composed of numerous models used by the EPA in order to estimate not only actual process costs, but also the costs that are deferred as a result of waste reduction and energy savings,” the team’s final report said.
Pranda said the data collected from the EPA CoEAT tool was used to “verify the feasibility of the upgrades being done to the facility.”
José Lozano M.S. ’88, Ph.D. ’91, laboratory director at the Ithaca Area Wastewater Treatment Facility, said that starting in the middle of February, instead of composting food waste from dining halls, workers will send waste to the Ithaca Wastewater facility.
“The CUSD team was able to successfully communicate to a diverse audience the environmental, and economic, benefits of anaerobic digestion over composting,” Lozano said.
He added that the team’s findings showed the wide array of benefits that anaerobic digestion could provide.
“In addition to reducing the carbon footprint and green house gases emissions over composting, anaerobic digestion will produce biogas. The methane in the biogas can be used to produce heat and power or fuel for transportation,” he said.
Pranda said the CUSD Anaerobic Digestion team is hopeful that the plant will refer to the findings of their study.
“Hopefully, our research will be used by the plant in order to make predictions about its energy production and usage,” Pranda said. “Once the plant begins accepting a larger volume of food waste, our research can be used in making decisions regarding the management of any excess energy.”