SoylentNews

An Anonymous Coward writes:

Urine has lots of nitrogen and phosphorus—a problem as waste, great as fertilizer:

Removing urine from wastewater and using it as fertilizer has the potential to decrease nutrient loading in water bodies and boost sustainability by making use of a common waste material.

In excess, nitrogen and phosphorus in our waste streams can stimulate algal blooms and create conditions dangerous to marine and lake ecosystems and human health. According to the website of the Rich Earth Institute, a Vermont-based company focused on using human waste as a resource, most of the nitrogen and phosphorus in wastewater comes from human urine, even though it makes up only 1 percent of wastewater. Removing urine could remove 75 percent of the nitrogen and 55 percent of the phosphorus from municipal wastewater treatment plants. And those nutrients could then be recycled for use as fertilizer.

[...] If it can be separated, urine can act to partly sterilize itself. The nitrogen in urine leaves the body as urea, a simple organic compound. Bacteria in pipes typically break down urea into ammonia. When urine is sitting in a container, the ammonia raises the pH of the solution to about eight or nine. The high pH environment kills any pathogens from the body that might have entered the urine, Vinnerås said.

“It’s like a Twinkie,” Noe-Hays said, referring to urine’s long shelf-life.

[...] Gardeners often use urine as fertilizer, and Noe-Hays said it works wonders from his personal experience. Noe-Hays said there is no necessary concentration of nutrients for urine to be used as fertilizer. The mass of its components is what matters. If pouring 1,000 gallons of urine on an acre, there are about 50 pounds of nitrogen added. Using a concentrate 10 times stronger than diluted urine, only 100 gallons would need to be applied to get the same impact, Noe-Hays said. “The hay doesn’t care whether you’re applying the concentrate or the dilute,” he continued. “It just matters how many total pounds of fertilizer it gets.”

[...] Water has been a big focus in the realm of climate change concerns, and Broaddus sees more people getting interested in small wastewater treatment options and a circular water economy. Wastewater has so much to offer—energy, nutrients, and information—and the more people can understand the system, the smaller it can get, Broaddus said.

Urine diversion fits into a circular water economy by connecting some of the dots. The water people drink and excrete may come back around to fertilize the vegetables prepped for a salad. For it to be more widely accepted by gardeners and farmers alike, shifts in both mentality and plumbing are important next steps.

Original Submission