MEMBRANE BIOREACTOR FOR THE TREATMENT OF SIMULATED WASTEWATER

The biological treatment system at Johnson Space Center consists of an anaerobic packed bed for denitrification and carbon removal and a novel aerobic reactor for nitrification. The aerobic reactor, known as the tubular reactor, is an attached growth biofilm system consisting of eight 200 feet long, 1/8-inch ID tubes, in which the biofilm grows inside the tubing in direct contact with the wastewater. Problems with the tubular reactor include low ammonia conversion rates and high operational maintenance requirements.The purpose of this work is to identify a biological treatment system to replace the tubular reactor in the Johnson Space Center water recovery system. The biological reactor must meet two important criteria. One constraint for the operation of an aerobic reactor in a zero gravity environment is bubble-less aeration, thus the reactor must be operational in a space environment. In addition, a highly efficient reactor is necessary for the conversion of ammonia to nitrate to prevent ammonia removal in the RO, which reduces the life of the treatment unit. A membrane-aerated bioreactor has been constructed and treatment efficiency is currently under investigation. Results from this study indicate the appropriateness of using membrane-aerated bioreactors in a recycle system.