Regenerable Microbial Check Valve (RMCV) technology has been developed for long duration missions such as a Lunar Base or Mars Sprint, where resupply logistics favors minimization of the use of expendible hardware. The process is illustrated schematically above. During normal operation the process water stream flows directly through the cartridge containing Iodinated Ion Exchange Resin. When the resin becomes depleted, it is regenerated by re-directing flow first through a packed bed of crystalline elemental iodine and then into the RMCV. The regeneration can be triggered based upon a number of factors such as: time, total flow through the cartridge, or the results of off line I2 analysis (i.e. using the Diode Array Spectrometer to be incorporated into the CHeCS system for ISSA). The ideal method of control of the RMCV technology is through the use of an on-line iodine monitor which triggers regeneration when residual I2 in the effluent falls below a pre-determined level. This methodology has been embodied in a prototype, incorporating a Pre-Development version of the Iodine Bench (Astro International) for PCWQM. The unit was tested at a flow rate of 100 mL/min and delivered to NASA (Johnson Space Center). This technology development resulted in the NASA Invention of the Year Award for 1993, in both Government and Commercial categories.
More information can be obtained from the following publications:
Atwater, J.E., Wheeler, R.R., Sauer, R.L., and Schultz, J.R., Advanced Development of the Regenerative Microbial Check Valve, SAE Technical Paper Series No. 932175, presented 23rd International Conference on Environmental Systems, Colorado Springs, July 1993.
Atwater, J.E., and Wheeler, R.R., Regenerable Biocide Delivery Unit, Phase II Final Report NASA Contract NAS9-18361 1992.
Atwater, J.E., Wheeler, R.R., Olivadoti, J.T., and Sauer, R.L., Chemistry and Kinetics of I2 Loss in Urine Distillate and Humidity Condensate, SAE Technical Paper Series No. 921314, presented at 22nd International Conference on Environmental Systems, Seattle, July 1992.
Atwater, J.E., Wheeler, R.R., Olivadoti, J.T., Flanagan, D.T. and Sauer, R.L.,Regenerable Microbial Check Valve: Life Cycle Tests Results, SAE Trans. J. Aerospace, 101, 1098, 1992.
Colombo, G.V., Jolly, C.D., and Sauer, R.L., Regenerable Biocide Delivery Unit, SAE Technical Paper Series No. 911406, presented 21st International Conference on Environmental Systems, San Francisco, July 1991.