Characterization of Urine Supernatant Following Struvite Precipitation for Space Colonization Applications

Long term space habitation on the moon or mars will require a constant food and water supply. Struvite, the precipitate formed in urine, can be used as a nutrient source for the growth of crops. The supernatant remaining after precipitation is a water source that must be reclaimed in order to maintain a constant water supply. The objective of this investigation was to characterize the urine supernatant in order to facilitate the development of a water reclamation method. Additionally, the investigation sought to identify any potential benefits of the urine supernatant for other applications on a space habitat. The high levels of organic contaminants found within the urine supernatant indicated that a combination of biological, physical, and chemical treatments must be employed in order to reclaim the urine supernatant as potable water. The urine supernatant also displayed a buffer capacity that could be useful in applications such as maintaining pH within the wastewater collection tank.