Development and Testing of a Microwave Powered Solid Waste Stabilization and Water Recovery System 2006-01-2182

A Microwave Powered Solid Waste Stabilization and Water Recovery Prototype system has been developed for the treatment of solid waste materials generated during extended manned space missions. The system recovers water initially contained within wastes and stabilizes the residue with respect to microbial growth. Dry waste may then be safely stored or passed on to the next waste treatment process. Using microwave power, water present in the solid waste is selectively and rapidly heated. Liquid phase water flashes to steam and superheats. Hot water and steam formed in the interior of waste particles create an environment that is lethal to bacteria, yeasts, molds, and viruses. Steam contacts exposed surfaces and provides an effective thermal kill of microbes, in a manner similar to that of an autoclave. Volatilized water vapor is recovered by condensation. Benefits of microwave power include rapid heat-up and cool-down, and selective heating of water by the direct absorption of electromagnetic radiation, thus minimizing conductive and convective losses, and reducing drying times. This translates directly into reduced size and power requirements, and lower Equivalent System Mass (ESM). Stabilization with respect to microbial growth has been demonstrated using a variety of challenge contaminants, including: bacteria, fungi and a virus. Water recoveries greater than 90% have also been achieved.