Development and testing of a TRL 5 bioreactor for pretreatment of a lunar surface wastestream

Water is the most critical life support element, representing 65% of the daily mass input for crew members even under the most stringent water use approaches. A reliable water source is therefore a critical concern for long term space habitation, whether in orbit (e.g. ISS), on the moon, Mars, or beyond. Water recovery systems currently under development for space missions are intensive users of resources including power for processes such as distillation and consumables for post-treatment based on adsorption and chemical oxidation of contaminants. As such, current designs exchange one cost (stored water) for others (power generation, stored consumables). Logistic savings characteristic of water recycling would be better reduced by implementing alternative, low-input systems. A pre-distillation bioreactor would require few resources while substantially improving system performance: >90% removal of wastewater organics including surfactants, pH stabilization, oxidation of NH₄ ⁺ to NO₃ ^-, (up to 80%), and improved distillation brine properties. We report on the design, construction, and testing of a TRL 5 biological membrane aerated reactor for pre-treatment (carbon and ammonia oxidation) of an early planetary base (e.g. Lunar) wastewater capable of integration with physio-chemical systems.