The next time you take a bathroom break during a Florida Gators home football game, you just may be giving back to Florida Field.
UF researcher Treavor Boyer, along with his student assistants, developed a urine separation system that allows the urine in a building’s bathrooms to be stored, treated and reused as fertilizer. With the success of the system, Boyer has his sights set on implementing the process at Ben Hill Griffin Stadium.
Urine is comprised of about 80 percent nitrogen, which is used as a fertilizer on athletic fields. Boyer and his team ran calculations on the number of people at each football game, how often each person would go to the bathroom during a game, how much they would urinate, and how many toilets and urinals are located in the stadium.
“It turned out that if you were to collect all the urine from the seven home football games, it would have enough nitrogen to meet the growing needs of the field for the entire year,” said Boyer, an associate professor in UF’s Engineering School of Sustainable Infrastructure and Environment
He explained that by collecting the urine after UF’s last home football game, which is typically played at the end of November, the urine would be stored for several months. This storage time would allow any viruses in the urine to deactivate, and the urine would be ready to use as fertilizer when turf management begins on Florida Field in the spring.
The system Boyer has developed uses waterless urinals and no-mix toilets to separate the urine and harvest nitrogen. Fertilizer is not the only benefit of his research, though, as Boyer says the system could cut back on UF’s water usage by about 20 percent.
“When you implement this system of urine separation, you save a tremendous amount of water,” he said. “Not only do you save water but you save energy, because the fresh water plant doesn’t have to produce as much water and the wastewater plant doesn’t have to treat as much water.”
Jason Kruse, a UF assistant professor of environmental horticulture and a turfgrass specialist, has assisted Boyer on his research and believes that urine could definitely work as a fertilizer for Florida Field.
“If you captured the urine at the stadium during games, there would be enough to meet the annual needs and then some of the plant, and probably enough for the whole campus,” Kruse said.
Florida Field is currently fertilized by controlled-release nitrogen through a system of fertigation, which incorporates fertilizer into the watering system. Fertilizing with urine would require a different system, and the urine should be applied to the field more frequently and at lower rates. Still, Kruse said, this would just be a slight change in management and would still make the system feasible.
Kruse said that the science and numbers behind the urine fertilizer work, but the larger issue is the infrastructure changes that would need to be made to collect and store urine.
Beyond that, he said social acceptability will probably be a challenge.
“If people understood that you’re spraying urine on the field, some people might have a harder time wrapping their heads around that than others,” he said. “From a health standpoint, my understanding is that after it’s been stored and basically fermented long enough, it addresses the concerns of pathogens or any health concerns really. But I think that would be an initial sort of push-back by some people.”
For Boyer, the next step is proving how effective the urine can be.
“The suggestions I’ve been given is that we really need to do a demonstration project to show that, yes, the turf is going to be as green – as strong – as the current fertilizer we’re using,” he said. “The color of the grass is very important to a lot of people, so that is one of the first things I think we have to prove, that it’s going to look as good as the current fertilizer.”
Boyer added, “It’s exciting because it’s feasible and could have a huge impact, but at the same time there are some major hurdles in terms of convincing people that it does work as well on the turf side.”
The process is explained visually in this University of Florida video.