REGENERABLE BIOCIDE DELIVERY UNIT

THE POTABLE WATER SYSTEM ON THE SPACE SHUTTLE USES A MICROBIAL CHECK VALVE (MCV) AS A BIOCIDE GENERATOR. THE MCV IS A REPLACEABLE CARTRIDGE THAT IS PACKED WITH A SPECIALIODINATED ION EXCHANGE RESIN. THIS RESIN CONTAINS IODINE WHICH IS RELEASED INTO THE WATER AS IT PASSES THROUGH THE RESIN AT A LEVEL ESSENTIALLY INDEPENDENT OF FLOW RATE, AND WITHOUT NEED OF INSTRUMENTATION OR CONTROLS. THE PRESENT DESIGN CAPACITY OF THE SHUTTLE MCV IS APPROXIMATELY 30 DAYS FOR A CREW OF SEVEN. THE SPACE STATION AND OTHER LONG TERM MISSIONS WILL USE RECLAIMED WATER TO REDUCE THE NEED FOR RESUPPLY. INVESTIGATIONS USING THE MCV ON WATER REPRESENTATIVE OF THATPRODUCED BY WATER RECOVERY SYSTEMS SHOW THAT THE MCV IS CAPABLE OF IODINATING THE WATER PRODUCED BY THESE SYSTEMS. IN ADDITION, FEASIBILITY TESTS HAVE SHOWN THAT THE RESIN IS CAPABLE OF BEING REGENERATED INSITU. AN INSITU REGENERABLE MCV WOULD BE A SIMPLE AND RELIABLE BIOCIDE DISPENSER THAT WOULD NOT REQUIRE FREQUENT REPLACEMENT OF MCVCARTRIDGES.