Waste more, want not.
Food waste at UNLV had been diverted to a local composting facility and pig farm since 2009. But now an in-vessel composter, operational since May, not only keeps that waste on campus, but it also allows many additional materials to be composted from landscape waste to paper products like bowls, napkins, plates, and plant-based utensils.
“The composter has been an incredible resource on campus for the Student Union,” said Jon Tucker, executive director, Student Union & Event Services. “As we work to divert trash out of landfills and into reusable resources, this composter enables us to work with Aramark to compost food waste from our catered events. It is a great piece as UNLV continues to work to be more sustainable.”
An estimated 3.7 tons has been composted on campus that otherwise would have been landfilled, says Tara Pike, UNLV sustainability coordinator. Because of the composter, Aramark/UNLV Dining catered events in the Student Union will be zero-waste events with compostable service ware.
Carbon and nitrogen materials are combined in a large mixer and then directed into the tumbler, where it stays for at least five days. Soil exits the tumbler during the rotating and aerating process. The soil goes through a screen to remove contamination and travels up a 72-inch long conveyor belt. Then the soil is cured in a bunker for at least 30 days and its temperature is recorded daily.
Heat is the mechanism by which everything breaks down. A temperature above 130 degrees celsius kills pathogens such as e-coli and salmonella.
“We want to keep the good bacteria, and we want to kill the bad bacteria,” Pike said.
The soil’s use on campus will evolve as its quantity is assessed.
“Hopefully, the finished compost will reduce fertilizer use on our campus turf areas,” Pike said. “And it will allow Facilities Management to partner with academic units to conduct research and or host student projects.”
Kurt M. Regner, associate biology professor in residence, took up an offer for professors to study the soil. Regner is using the composted soil in his phage discovery class he teaches with Christy Strong. Lab students in the class isolate and purify bacteriophages from compost.
“Bacteriophage literally means bacteria eater, and these viruses are found wherever there are bacteria,” Regner said. “Soils with high organic matter content and compost are full of bacteria and bacteriophages.Last fall, students collected soil from their backyards and around White Hall, but struggled to find phages since our desert soil has low organic matter and low bacterial populations. Our samples from the Community Garden planter beds and the fresh compost were loaded with bacteriophages.”