UCI has made a name for itself in sustainability by providing incentives for switching to electric and plug-in hybrid vehicles, indicating how much water it takes to produce each food item in the dining halls, and removing trash cans from these facilities. A general cultural shift to being more environmentally conscious saw a push to recycle, but there’s a new means of eco-friendly disposal in town: composting.
According to the Natural Resource Defence Council (NRDC), composting refers to the natural degradation of organic matter by decomposition. This process is carried out by organisms called decomposers, which include fungi, mold and worms. Composting food scraps and other natural substances is a way to speed up decomposition, resulting in a nutrient-rich material that can be used as fertilizer in commercial agriculture or home gardening.
Compost discards can be processed on a larger, industrial scale, or in communities and individual households, according to the NRDC. There are services that arrange discard pickups in order to add it to preexisting compost piles, such as CompostNow and other local waste management programs.
Having separate disposal methods for organic matter may seem counterintuitive, because composting is just speeding up the inevitable process of decomposition.
However, composting involves aerobic decomposition, which means it is carried out by organisms that require oxygen. When organic matter is buried under biodegradable materials, the decomposers’ oxygen supply is cut off, and they cannot perform their required function.
Compromising natural decomposition in this way allows other organisms that do not require oxygen to break down organic waste by anaerobic decomposition. Anaerobic decomposition leads to the release of biogas, which is a 1:1 combination of methane and carbon dioxide gases. According to the EPA, methane is 28% to 36% more effective than carbon dioxide at trapping atmospheric heat. This means that reducing methane emissions is an integral part of alleviating climate change.
However, carefully monitored anaerobic respiration can be used to help mitigate the climate crisis as well. UCI composting and food waste management is done on a commercial level and deliberately sends food waste to be anaerobically decomposed.
Food waste from campus dining facilities is taken to a local processing center, where it is pulverized by Centralized Organic Recycling equipment (CORe). The resulting slurry is a nutrient rich food source for anaerobic bacteria. The slurry is then transported to Carson, where it is pumped into digester tanks. These tanks are heated to 96 degrees Fahrenheit, which is the optimal decomposition temperature.
The biogas released during the anaerobic breakdown of campus food waste is collected and used to generate electricity that powers water recycling plants. Any remaining slurry is then composted, fully maximizing the output of the decomposition process.
The Anteatery, Brandywine, Phoenix Food Court, Anteater Recreation Center and the Alumni Café are all certified zero-waste facilities on campus, meaning 95% of all food waste from these locations never make it to landfills, and are instead sent to facilities for anaerobic decomposition.
This year, UCI was named No. 2 in Sierra magazine’s “Cool School” ratings of sustainable colleges, and it has been in the Top 10 of this list for 12 consecutive years. Campuswide, UCI currently has an 80% waste diversion rate, meaning the campus only sends 20% of its trash to landfills. According to UCI Recycling and Waste Management, the campus “is well on its way to its zero-waste designation,” which will be awarded when the waste diversion rate reaches 90%.
Lauren Le is a STEM Intern for the fall 2021 quarter. She can be reached at laurenl9@uci.edu.
