Search Results

Direct osmotic concentration (DOC) is a membrane treatment process for reclamation of space craft wastewater. It incorporates a novel system architecture that includes a forward osmosis (FO) and reverse osmosis (RO) subsystem for hygiene (gray) water, and a membrane distillation subsystem for the treatment of urine and humidity condensate. The products of these subsystems are combined and then post-treated by a catalytic oxidation subsystem. This paper documents progress made during the second year of a three year Rapid Technology Development Team (RTDT) effort.

The purification of waste water is a critical element of any long-duration space mission. The Vapor Phase Catalytic Ammonia Removal (VPCAR) system offers the promise of a technology requiring low quantities of expendable material that is suitable for exploration missions. NASA has funded an effort to produce an engineering development unit specifically targeted for integration into the NASA Johnson Space Center's Integrated Human Exploration Mission Simulation Facility (INTEGRITY) formally known in part as the Bioregenerative Planetary Life Support Test Complex (Bio-Plex) and the Advanced Water Recovery System Development Facility. The system includes a Wiped-Film Rotating-Disk (WFRD) evaporator redesigned with micro-gravity operation enhancements, which evaporates wastewater and produces water vapor with only volatile components as contaminants. Volatile contaminants, including organics and ammonia, are oxidized in a catalytic reactor while they are in the vapor phase.

Direct osmotic concentration (DOC) has been identified as a potential wastewater treatment process for potable reuse in advanced life support systems (ALSS). As a result, further development of the DOC process is being supported by a NASA Rapid Technology Development Team (RTDT) program. DOC is an integrated membrane system combining three unique membrane separation processes including forward osmosis (FO), membrane distillation (MD), and reverse osmosis (RO) that is designed to treat separate wastewater streams comprising hygiene wastewater, humidity condensate, and urine. An aqueous phase catalytic oxidation (APCO) process is incorporated as post treatment for the product water. In an ongoing effort to improve the DOC process and make it fully autonomous, further development of the three membrane technologies is being pursued.

This paper describes the results of performance testing of the Vapor Phase Catalytic Ammonia Removal (VPCAR) technology. The VPCAR technology is currently being developed by NASA as a Mars transit vehicle water recycling system. NASA has recently completed a grant to develop a next generation VPCAR system. This grant concluded with the shipment of the final deliverable from Water Reuse Technology Inc. to NASA on August 31, 2003. This paper presents the results of initial performance testing of the VPCAR-EDU. Mass, power, volume, and acoustic measurements are reported. Product water purity analysis for a Mars transit mission and a planetary base simulated wastewater feeds are also reported.

This paper provides an assessment of the technical readiness of the Vapor Phase Catalytic Ammonia Removal Process (VPCAR). The VPCAR technology is a fully regenerative water recycling technology designed specifically for applications such as a near term Mars exploration mission. The VPCAR technology is a highly integrated distillation/catalytic oxidation based water processor. It is designed to accept a combined wastewater stream (urine, condensate, and hygiene) and produces potable water in a single process step which requires no regularly scheduled re-supply or maintenance for a 3 year mission. The technology is designed to be modular and to fit into a volume comparable to a single International Space Station Rack (when sized for a crew of 6). This paper provides a description of the VPCAR technology and a summary of the current performance of the technology.