It’s a classic fact that astronaut urine can be processed into drinkable water. Now a new bioreactor could turn the waste filtered from that pee into an energy source as well.
When water supplies run low on a space mission, astronaut urine can be treated to become drinking water. But the waste removed is still, well, waste. University of Puerto Rico scientists Eduardo Nicolau and Carlos R. Cabrera, working in collaboration with the NASA Ames Research Center, came up with a new approach to make use of the waste.
First they used a process called forward osmosis to hydrolyze urea from urine. That urea was converted into ammonia using an enzymatic bioreactor. Then the ammonia was electrochemically oxidized to generate electrons and molecular nitrogen, Nicolau told DNews.
Although there have been previous attempts to develop urine bioreactors, they typically didn’t turn urine into a fuel cell for power. The idea with this new system is to both remove urea from wastewater and generate valuable components from human waste, Nicolau explained.
The system was able to remove more than 80 percent of organic carbons from the urine, and convert approximately 86 percent of the urea to ammonia, Nicolau and his colleagues reported in ACS Sustainable Chemistry & Engineering (abstract).
Besides being a potentially valuable recycling process for space, the new Urea Bioreactor Electrochemical system could also be used on Earth wherever there’s wastewater treatment involving lots of urea or ammonia, according to the ACS News Service. Who knows, maybe dive bars could become an endless power source.
Photo: NASA astronaut Tom Marshburn updates software on the Waste and Hygiene Compartment’s Urine Processor Assembly in the International Space Station. Astronaut urine could be recycled into fuel. Credit: NASA, Flickr Creative Commons.