This weekend, peak peony blooms are predicted at the Nichols Arboretum in Ann Arbor. Scientists from the University of Michigan are using part of the peony garden as an experiment to test urine-derived fertilizer. It's called Pee for the Peonies.
“When we first did this, it was pee on the peonies. And they're like, ‘You want me to, like, drop my drawers and pee?’ And so we're like, ‘Okay, okay, wait a minute. Stop, stop the presses.’ And so we then moved to 'pee for the peonies,'” said Nancy Love, an environmental engineer and professor at the University of Michigan.
Love and her team have created a pee-cycling system that takes urine from a special collection toilet on campus and turns it into a powdered clean fertilizer for plants.
I needed to see the collection toilet in the engineering building for this story. Visit the john that waters your lawn. Contribute some pee for the peony. It was not as easy to find as I had anticipated, but after asking someone for directions and wandering around the large academic building for a mere 30 minutes, I found the commode.
There’s a urine separating toilet in the women’s bathroom, just lined up in a stall next to a regular toilet. A yellow sign reads, “Pee-Only Stall” with what appears to be a smiling urine droplet cartoon. The men’s bathroom next door supposedly has a waterless urinal, but I was not brave enough to investigate.
The toilet separates and collects urine on the second floor bathroom and sends it down a level to a small processing room.
The urine is pasteurized, concentrated and de-contaminated. The process filters things like bacteria, caffeine, pharmaceuticals and that specific strong ammonia smell. The process also selectively removes key nutrients. Phosphorous, potassium, nitrogen — elements found in regular fertilizers. They are then able to engineer the nutrient ratios in the final product.
“It turns out peonies and any flowering plant really needs more of the phosphorus and the potassium and less of the nitrogen. And so it works beautifully,” said Love.
Love is engineering more efficient solutions to wastewater processing and fertilizing. Most of us might not think much of what we flush, but the U of M engineers are creating new solutions from our disposals.
“We are very inefficient in our use of nitrogen and phosphorus in particular, and potassium, on our planet,” said Love.
The way we manage our waste is surprisingly outdated. Everything that goes down the drain mixes together. That system made more sense when we put it in place so that we could live in cities. But, “if we were to look at it today, we would say, ‘No, no, no. We need to separate out these things so that we can reuse these materials in appropriate ways,’” said Love.
In the United States, we use billions of gallons of potable water per year in our toilets.
“So if you have a urine separation system, you reduce water use. And potable water for just flushing is about 20 to 25% of your water use in a building,” said Love.
Urine recycling can also offset things like fertilizer production.
“We believe that it is one of the paths to a future that really helps our soil, helps our communities, really helps our planet,” said Love.
Which brings us back to the peonies.
“So we go out in the mornings when it's quiet and the birds are chirping. It's really pretty,” said Love.
Love and her graduate students were out on a Wednesday morning to survey their experimental plots at the Arboretum.
They were counting blooms, buds and blasts. Love described the blasts to her students, pointing to a small darkly colored bud-looking part of the plant. She said this part would not turn into a bud. The students fanned out across the experimental plots with yard sticks to measure and record the status of the peonies. The plants are paired in the plots, with half getting the urine-derived fertilizer and the other half getting plain water.
They are measuring the effect of their fertilizers on the peonies. It's a garden experiment to benefit horticulture needs and help educate people about wastewater.
In a video online, the lab group stands together and shouts, “We’re number one at number one.”
