A U.S. researcher is developing a technology that would enable urine treatment to happen quickly, thus promoting the recovery of nitrogen that can be sold as agricultural fertilizer.
Kevin Orner, a West Virginia University (WVU) Benjamin M. Statler College of Engineering and Mineral Resources assistant professor, is developing a technology that can treat urine on site rather than at a remote, centralized wastewater treatment facility. The technology could reside underneath a toilet, enabling urine treatment to happen quickly and promoting the recovery of nitrogen, a nutrient that can be sold as a fertilizer.
Orner’s findings, published in the journal Environmental Technology, make urine recycling more feasible in terms of integration into existing infrastructure and could reduce the amount of nutrients that enter lakes and rivers.
Waste recycling isn’t a new concept. Farmers have long used manure to enrich soil and urine to repel pests. Processes for turning feces into fertilizer have been implemented on an industrial scale, and infrastructure and programs for recycling human urine are already operating in places like Nairobi, Kenya and Brattleboro, Vermont.
For Orner, he envisions toilets that separate urine and feces, allowing each of those waste products to be collected, treated and converted into a useful agricultural fertilizer. The approach Orner sees as most viable requires no power to operate. A urine-separating toilet’s design separates solids from liquids, then sends the urine to a nutrient recovery unit that’s located in or attached to the toilet itself, or potentially housed in a residential or commercial basement.
Urine-separating toilets exist, not only in Kenya and Vermont, but from Oregon to Paris and the Netherlands. Orner has a collaborator in Costa Rica who “is interested in taking the lessons learned from Brattleboro and applying those to Monteverde, an ecotourism community in the Cloud Forest,” Orner said.
Orner’s work is significant because, by priming the collection and treatment reservoir with an inoculation of soil containing helpful microorganisms, adding in carbon pellets to provide a growing surface for bacteria that are key to the treatment process, and using a fill-and-draw procedure whereby small quantities of treated urine are removed and fresh urine is incrementally added, his team was able to significantly accelerate treatment – reducing a process that could take weeks down to a day in one phase of the study.
The goal is to transform waste collection and treatment from an environmentally harmful service that costs money to an environmentally beneficial service that makes money.
Read how one company is turning human urine into biofertilizers, here
Read the NOV/DEC 2022 issue of New AG International, free to view here