A NOVEL MEMBRANE-BASED WATER RECLAMATION POST-TREATMENT UNIT

FOR FUTURE LONG-TERM SPACE MISSIONS SPACECRAFT WATER RECYCLE SYSTEMS ARE NOW UNDER DEVELOPMENT. ONE WATER RECYCLE SYSTEM STUDIED BY NASA INCLUDES A REVERSE-OSMOSIS (RO) SUBSYSTEM THAT WILL PRODUCE REUSABLE WATER FROM WASH WATERS. THE CONCENTRATE FROM THE RO SUBSYSTEM WILL BE COMBINED WITH URINE AND DISTILLED TO RECOVER MORE WATER. THIS PROJECT WILL INVESTIGATE THE USE OF AN ADDITIONAL RO COMPONENT AS THE INITIAL STEP OF THE POST-TREATMENT REQUIRED TO REMOVE THE CONTAMINANTS THAT ARE LEFT IN THE PHASE-CHANGE SUBSYSTEM DISTILLATE. THIS RO UNIT WILL USE THE SAME, NOVEL, FOULING-RESISTANT COMPOSITE HOLLOW-FIBER MEMBRANE MODULES BEING DEVELOPED FOR NASA FOR THE RECYCLE OF SPACECRAFT WASH WATERS, AS WELL AS FOR OTHER APPLICATIONS FOR WHICH FOULING RESISTANCE IS IMPORTANT. IF RO IS USED AS THE INITIAL STEP IN THE TREATMENT OF THE DISTILLATE, THEN THE LOAD ON THE REMAINING CONVENTIONAL DISTILLATE TREATMENT STEPS WILL BE REDUCED, ALLOWING A MUCH LONGER LIFE FOR THE EXPENDABLE COMPONENTS. FURTHERMORE, THIS MEMBRANE UNIT WILL ACT AS A BARRIER TO PROTECT THE REST OF THE POST-TREATMENT TRAIN SHOULD THE PHASE-CHANGE SUBSYSTEM FAIL. THE PHASE I PROGRAM WILL DETERMINE THE FEASIBILITY OF USING THESE RO MEMBRANE MODULES FOR POST-TREATMENT APPLICATIONS BY TESTING THEM ON SYNTHETIC AND ACTUAL DISTILLATES. THE PHASE II EFFORT WOULD BEGIN TO DEVELOP FLIGHT HARDWARE.