title: Comparative performance of A2/O and a novel membrane-bioreactor-based process for biological nitrogen and phosphorus removal.
abstract: The comparison between a novel membrane bioreactor (MBR) system and a conventional anaerobic-anoxic-aerobic (A2/O) system was conducted using synthetic wastewater (SWW) and municipal wastewater (MWW). Each system was operated at an overall hydraulic retention time of 8 hours and solids retention time of 10 days. The MBR exhibited better overall system performance than the A2/O system, in terms of phosphorus removal. Nitrogen removal efficiencies were close in the two systems at 73 to 74% in both runs, while phosphorus removal efficiencies were 96 and 74% (SWW run) and 80 and 75% (MWW run), for the MBR and A2/O, respectively. Effluent soluble chemical oxygen demand (COD) was less than 15 mg/L in the two systems during both runs. Phosphorus uptake by denitrifying phosphate-accumulating organisms accounted for 49% of the total uptake in the MBR compared with 33% in the A2/O during the SWW run. The dynamic test clearly showed that the MBR had better denitrification capacity than the A2/O system. The MWW run indicated that MBR ferments particulate COD better than A2/ O. The effect of the intermediate clarifier on MBR phosphorus removal was significant, with phosphorus uptake of 0.16 g/d in the SWW run and phosphorus release of 0.08 g/d in the MWW run, thus enhancing thetotal phosphorus removal in both cases.
authors.affiliation: Department of Civil and Environmental Engineering, University of Western Ontario, London, Ontario, Canada.
authors.forename: MinGu
authors.initials: M
authors.lastname: Kim
authors.forename: George
authors.initials: G
authors.lastname: Nakhla
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D019149:Bioreactors; D008567:Membranes, Artificial; D009584:Nitrogen / Q000737:chemistry*; D010100:Oxygen / Q000378:metabolism; D010758:Phosphorus / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical
chemical_list: D008567:Membranes, Artificial; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D009584:Nitrogen; D010100:Oxygen