Performance of a TRL 5 Bioreactor for Pretreatment of an Extended Habitation Wastestream

Water is one of the most critical and costly life support elements, even under the most stringent water use approaches. Technologies that can increase the sustainability of water processing by reducing expendables and helping to close the water loop can have large impacts on mission costs. Current technologies for water processing are intensive users of resources, including power for processes such as distillation, and consumables for preand post-treatment. In particular, urine pre-processing requires the continuous consumption of hazardous and corrosive chemicals. Further, current recovery rates are limited partly by the chemical pre-processing, and the brine produced from this pre-treated chemical is challenging to process. Biological pre-treatment may offer substantial efficiencies over traditional technologies, and offer secondary benefits with only minor costs. For the past 9 months, we have operated a TRL 5 membrane aerated bioreactor processing an extended habitation waste stream (urine/hygiene/humidity condensate). The reactor has successfully processed the wastewater at loading rates of 20 L/d and 30 L/d and is currently being challenged at 40 L/d. The reactor has exceeded 70% NH4 + conversion, 86% DOC conversion, 55% TN reduction, and maintained a pH < 7. Conversion rates for NH4 + and DOC are approaching 1 g/m 2 -d. Finally, preliminary gas phase measurements reveal that the total O2 consumption is ~100 g/d, while CO2 production was ~ 4g/d and N2 production was estimated at 20 g/d (~13 L/d).