WASTEWATER RECLAMATION IS A VITAL ASPECT OF PROLONGED SPACE TRAVEL. ONE AREA THAT IS PARTICULARLY CHALLENGING IS URINE RECLAMATION. CURRENT INTERNATIONAL SPACE STATION (ISS) SYSTEMS ALLOW FOR 70% RECOVERY. NASA AIMS TO INCREASE WASTEWATER RECOVERY TO 85% OR GREATER. A FURTHER CHALLENGE WITH WATER RECOVERY FROM WASTEWATER BRINES IS MINIMIZATION OF MINERAL SCALING ON PROCESSING EQUIPMENT. THE OVERALL GOAL IS TO INTRODUCE PERVAPORATION A MEMBRANE PROCESS NEW TO NASA FOR HIGH RECOVERY (>=85%) OF WATER FROM ISS WASTEWATER AN BRINES WHILE SIMULTANEOUSLY DEVELOPING NEW MEMBRANES FOR PERVAPORATION. THIS WILL INCLUDE EVALUATING ROUTES TO REPLACE CURRENT WASTEWATER PROCESSING VAPOR COMPRESSION DISTILLATION (VCD) WITH PERVAPORATION. PERVAPORATION IS A MEMBRANE PROCESS WHERE THE DRIVING FORCE FOR TRANSPORT IS VAPOR PRESSURE DIFFERENCES (OFTEN CREATED VIA EITHER A VACUUM PUMP OR A SWEEPING GAS) OF THE PERMEATING SPECIES ACROSS THE MEMBRANE. PERVAPORATION IS ADVANTAGEOUS COMPARED TO PROCESSES LIKE DISTILLATION IN THAT IT CAN EASILY BE OPERATED AT AMBIENT TEMPERATURES. IT CAN BREAK AZEOTROPES AND LIMIT TRANSFER OF VOLATILE ORGANIC COMPOUNDS (VOCS) THUS LIMITING THE TRANSMISSION OF UNDESIRED SPECIES INTO THE PURIFIED WATER. PERVAPORATION IS CAPABLE OF HANDLING HIGHLY CONCENTRATED BRINES WHEN COMPARED TO CONVENTIONAL PROCESSES SINCE IT IS NOT LIMITED BY THE CONCENTRATION OF SOLUTES IN THE FEED. PERVAPORATION IS A UNIQUE PROCESS THAT IT CAN PRODUCE CLEAN WATER IN THE PRESENCE OF SALT COMPOUNDS AND ORGANIC COMPOUNDS BOTH OF WHICH ARE PRESENT IN URINE BRINE.
$267,108FY2020National Aeronautics and Space AdministrationNASA
Arizona State University, Scottsdale AZ