Ammonia Recovery System for Wastewater

NASA's Ammonia Recovery System for Wastewater was developed for potential use as part of the Environmental Control and Life Support Systems (ECLSS) on the International Space Station. The system uses an affordable media that is highly selective for ammonia. Ammonia concentrations in wastewater as high as 100,000 ppm can be reduced to less than 1 ppm. ECLSS conditions require low power usage, and the avoidance of high-temperature and high-pressure operations. The state-of-the-art for ammonia removal involves biological processes or ion exchange, and neither of these meets NASA's ammonia capture/recovery needs. Biological processes have high complexity, high volume requirements, and introduce contaminants in the effluent. Ion exchange is not very selective for ammonia, and requires regeneration, which requires large amounts of consumables and produces impure ammonia.