title: Nitrogen and phosphorus removal in an airlift intermittent circulation membrane bioreactor.
abstract: A new airlift intermittent circulation integrated bioreactor was developed for simultaneous nitrogen and phosphorus removal of wastewater, in which, circulation of mixed liquid between mixing zone and aeration zone was realized by aeration power, alternately anaerobic/anoxic bio-environment in mixing zone was realized by intermittent circulation and simultaneous nitrogen and phosphorus removal was obtained through strengthened denitrifying phosphorus removal process. Removal performance of the reactor was investigated and pollutant removal and transfer mechanism in one operation circle was analyzed. The experiment results indicated that under the influent condition of chemical oxygen demand (COD) concentration of 642.1 mg/L, total nitrogen (TN) of 87.4 mg/L and PO4(3-)-P of 12.1 mg/L, average removal efficiencies of COD, TN and PO4(3-)-P reached 96.4%, 83.2% and 90.5%, respectively, with the hydraulic residence time of 22 hr and operation circle time of 185 min. Track studies indicated that the separation of aeration and mixing zones and intermittent circulation of mixed liquid between the two zones provided distinct biological environments spatially and temporally, which ensured the occurrence of multifunctional microbial reactions.
authors: School of Environmental and Chemical Engineering, Dalian Jiaotong University, Dalian 116028, China.  ghy2721@sina.com
authors: Haiyan
authors: H
authors: Guo
authors: School of Environmental and Chemical Engineering, Dalian Jiaotong University, Dalian 116028, China; Department of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
authors: Jiandong
authors: J
authors: Chen
authors: School of Environmental and Chemical Engineering, Dalian Jiaotong University, Dalian 116028, China; Department of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
authors: Yun
authors: Y
authors: Li
authors: School of Environmental and Chemical Engineering, Dalian Jiaotong University, Dalian 116028, China; Department of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
authors: Tengteng
authors: T
authors: Feng
authors: School of Environmental and Chemical Engineering, Dalian Jiaotong University, Dalian 116028, China; Department of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
authors: Shoutong
authors: S
authors: Zhang
mesh_terms: D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D008567:Membranes, Artificial; D009584:Nitrogen / Q000302:isolation & purification*; D010100:Oxygen / Q000032:analysis; D010758:Phosphorus / Q000302:isolation & purification*
chemical_list: D008567:Membranes, Artificial; D010758:Phosphorus; D009584:Nitrogen; D010100:Oxygen
keywords: intermittent circulation; membrane bioreactor; nitrogen and phosphorus removal