Human waste on long-term journeys into space makes up about half of the mission's total waste, researchers said.
Recycling it is critical to keeping a clean environment for astronauts. And when onboard water supplies run low, treated urine can become a source of essential drinking water, which would otherwise have to be delivered from Earth at a
tremendous cost, they said.
Previous research has shown that a wastewater treatment process called forward osmosis in combination with a fuel cell can generate power.
Eduardo Nicolau, from Department of Chemistry and NASA Center for Advanced Nanoscale Materials, University of Puerto Rico, and his team decided to build on these initial findings to meet the challenges of dealing with urine in space.
They collected urine and shower wastewater and processed it using forward osmosis, a way to filter contaminants from urea, a major component of urine, and water.
Their new Urea Bioreactor Electrochemical system (UBE) efficiently converted the urea into ammonia in its bioreactor, and then turned the ammonia into energy with its fuel cell.
The system was designed with space missions in mind, but "the results showed that the UBE system could be used in any wastewater treatment systems containing urea and/or ammonia," the researchers concluded.
The report appears in the journal ACS Sustainable Chemistry & Engineering.