Inline Monitoring and Evaluation of Inorganic Gases from a Nitrification Membrane Bioreactor

Integration of the water and air treatment systems in confined habitats for extended duration space missions will require characterization of the constituents in the gases produced by biological water processors. A membrane bioreactor was constructed to accomplish nitrification as part of a denitrification-nitrification biological water processor to treat a simulated early planetary base wastewater. A gas chromatograph was installed inline to the influent and effluent gas lines of the membrane bioreactor to monitor nitrogen, oxygen, carbon dioxide and nitrous oxide. The inline monitoring system enabled sampling of gas effluent from the lumen of the membranes and from a gas-liquid separator. Mass flow of the gas streams was also measured to enable calculation of the mass flow rates of the four inorganic gases. We present the system design, describe gas chromatograph analysis, and demonstrate the use of data collected by the inline monitoring system to calculate mass flow rates of specific inorganic compounds in liquid and gas phases.