title: Biological treatment of a synthetic space mission wastewater using a membrane-aerated, membrane-coupled bioreactor (M2BR).
abstract: This paper describes the membrane-aerated, membrane-coupled bioreactor (M2BR), which was developed for wastewater treatment during long-term space missions because it achieves aeration and biomass separation using components that are compatible with microgravity conditions. In the experiments described herein, the M2BR was used to treat a synthetic wastewater formulated by NASA to simulate the wastewater typically collected during space missions. The M2BR was able to achieve more than 90% removal of both chemical oxygen demand (COD) and total nitrogen when it was fed a modified NASA wastewater that had a 4:1 COD to nitrogen ratio. When the full-strength synthetic wastewater was fed to the M2BR (COD:N=1), however, the nitrogenous pollutant removal efficiency was adversely affected because of either insufficient oxygen transfer to support nitrification (an air-fed M2BR) or insufficient electron donor to support denitrification (an oxygen-fed M2BR). In conclusion, the M2BR provides considerable promise for wastewater treatment during long-term space missions, although additional research is needed to identify the best approach to treat the space mission wastewater, which poses a unique challenge because of its low COD:N ratio.
authors.affiliation: Department of Civil Engineering, University of Minnesota, 122 Civil Engineering, 500 Pillsbury Drive SE, Minneapolis, MN 55455-0116, USA.
authors.forename: Ruoyu D
authors.initials: RD
authors.lastname: Chen
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Semmens
authors.forename: Timothy M
authors.initials: TM
authors.lastname: LaPara
mesh_terms: D000641:Ammonia / Q000032:analysis / Q000378:metabolism; D001419:Bacteria / Q000145:classification / Q000235:genetics; D019149:Bioreactors; D005374:Filtration; D008567:Membranes, Artificial; D009566:Nitrates / Q000032:analysis; D010100:Oxygen / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013026:Space Flight; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D014867:Water / Q000737:chemistry; D014871:Water Microbiology; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D008567:Membranes, Artificial; D009566:Nitrates; D012336:RNA, Ribosomal, 16S; D014867:Water; D000641:Ammonia; D010100:Oxygen