Grey Water Treatment under Microgravity Conditions: Mass Transfer and Kinetic Studies

An aerobic pressurized bioreactor system to treat grey water under microgravity conditions has been developed. The treatment system consists of a packed bed bioreactor and an oxygenation device attached to an external re-circulation line. The membrane module provides bubble-free oxygen, at very high concentrations and transfer efficiency. Mass transfer characteristics of the oxygenation module have been studied. Oxygen mass transfer in water is described using a resistance-in-series model. A generalized mass transfer correlation that predicts the oxygen mass transfer coefficient has been developed. Experiments have been conducted to study the nitrification of grey water at various residence times.