title: CFD simulation and optimization of membrane scouring and nitrogen removal for an airlift external circulation membrane bioreactor.
abstract: Cost-effective membrane fouling control and nitrogen removal performance are of great concern in airlift external circulation membrane bioreactors (AEC-MBRs). Computational fluid dynamics (CFD) model incorporating sub-models of bio-kinetics, oxygen transfer and sludge rheology was developed for the cost-effective optimization of a lab-scale AEC-MBR. The model was calibrated and validated by extensive measurements of water velocities and water quality parameters in the AEC-MBR. The validated results demonstrated that the optimized height of gas-liquid dispersion was at around 300mm. The shear stress on membrane surface was equalized and had an average value of 1.2Pa under an air flowrate of 1.0m(3)h(-1). The model further revealed that the high nitrogen removal efficiency (>90%) was achieved due to the high recirculation ratio driven by airlift force without destroying the oxygen deprivation and enrichment in the anoxic and oxic zone, respectively.
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: yangmin1113@126.com.
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: yswei@rcees.ac.cn.
authors.forename: Yuansong
authors.initials: Y
authors.lastname: Wei
authors.affiliation: School of Environment and Nature Resources, Renmin University of China, Beijing 100872, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Zheng
authors.affiliation: School of Energy and Power Engineering, Beihang University, Beijing 100191, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Yuan
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Jibao
authors.initials: J
authors.lastname: Liu
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Luo
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Rongle
authors.initials: R
authors.lastname: Xu
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Dawei
authors.initials: D
authors.lastname: Yu
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: ybfan@rcees.ac.cn.
authors.forename: Yaobo
authors.initials: Y
authors.lastname: Fan
mesh_terms: D001673:Biodegradation, Environmental; D019149:Bioreactors; D003198:Computer Simulation; D058440:Denitrification; D057446:Hydrodynamics; D007700:Kinetics; D008567:Membranes, Artificial; D008962:Models, Theoretical; D009584:Nitrogen / Q000302:isolation & purification*; D010100:Oxygen; D012722:Sewage / Q000737:chemistry*
chemical_list: D008567:Membranes, Artificial; D012722:Sewage; D009584:Nitrogen; D010100:Oxygen
keywords: Activated sludge model; Computational fluid dynamics; Membrane bioreactor; Oxygen mass transfer; Particle image velocimetry