Monitoring Performance of a Denitrifying Reactor Designed for Shuttle Testing

Ground studies are continuing at Kennedy Space Center to define the performance of the Immobilized Microbe Microgravity Water Processing System (IMMWPS), a denitrifying, fixed-bed reactor designed for shuttle flight-testing. The goal of these experiments was to define organic compounds that could be used as indicators of changes in reactor performance as to the removal of surfactant and to evaluate additional flight and sampling protocols. While changes in the breakthrough concentration of surfactant would provide insight into performance changes during the flight experiment, this breakthrough of surfactant in the flight system is undesirable due to operational problems resulting from foaming of the undegraded surfactant. By monitoring a degradation intermediate instead of the surfactant in the effluent, this problem could be avoided while monitoring any effects of microgravity on bioreactor performance during space flight. Results indicate that methyl taurine levels in the effluent may be used to study the effects of various flight protocols and conditions on reactor performance. Experiments to evaluate in flight sample preservation were also performed.