Supercritical Water Oxidation: Treatment of Human Waste and System Configuration Tradeoff Study

Supercritical water oxidation (SCWO) is a waste treatment and water recycling technology currently being developed for NASA by MODAR, Inc. Results are presented for SCWO of urine and feces in a laboratory unit sized approximately for an 8-person crew. Essentially complete conversion of organic carbon to CO₂ or char, and of organic nitrogen to N₂ and N₂ O, were demonstrated. All major heteroatoms (S, P, Cl, Na, K, Ca, and Mg) were efficiently removed from the process stream as ash. A tradeoff study was carried out to evaluate which configurations of a SCWO subsystem would be most favorable for use in a space facility.