title: Anoxic gas recirculation system for fouling control in anoxic membrane reactor.
abstract: Anoxic gas recirculation system was applied to control the membrane fouling in pilot-scale 4-stage anoxic membrane bioreactor (MBR). In the anaerobic-anoxic-anoxic-aerobic flow scheme, hydrophilic polytetrafluoroethylene (PTFE) membrane (0.2 μm, 7.2 m(2)/module) was submerged in the second anoxic zone. During 8 months operation, the average flux of the membrane was 21.3 L/(m(2)·hr). Chemical cleaning of the membrane was conducted only once with sodium hydroxide and sodium hypochlorite. Dissolved oxygen (DO) concentration in the second anoxic zone was maintained with an average of 0.19 ± 0.05 mg/L. Gas chromatography analysis showed that the headspace gas in the second anoxic reactor was mainly consisted of N2 (93.0% ± 2.5%), O2 (3.8% ± 0.6%), and CO2 (3.0% ± 0.5%), where the saturation DO concentration in liquid phase was 1.57 mg/L. Atmospheric O2 content (20.5% ± 0.8%) was significantly reduced in the anoxic gas. The average pH in the reactor was 7.2 ± 0.4. As a result, the recirculation of the anoxic gas was successfully applied to control the membrane fouling in the anoxic MBR.
authors: Research Institute for Environmental Technology and Sustainable Development, Korea University, Seoul 136-713, Korea. Electronic address: lhs1351@korea.ac.kr.
authors: Hansaem
authors: H
authors: Lee
authors: Department of Environmental Engineering, Korea University, Sejong 339-700, Korea.
authors: Daeju
authors: D
authors: Lee
authors: Department of Environmental Engineering, Korea University, Sejong 339-700, Korea.
authors: Seongwan
authors: S
authors: Hong
authors: Department of Environmental Engineering, Korea University, Sejong 339-700, Korea.
authors: Geum Hee
authors: GH
authors: Yun
authors: Department of Environmental Engineering, Korea University, Sejong 339-700, Korea.
authors: Sungpyo
authors: S
authors: Kim
authors: Dongbu Corporation, Seoul 135-523, Korea.
authors: Jung Ki
authors: JK
authors: Hwang
authors: Dongbu Corporation, Seoul 135-523, Korea.
authors: Woojae
authors: W
authors: Lee
authors: Department of Environmental Engineering, Korea University, Sejong 339-700, Korea. Electronic address: envzyun@korea.ac.kr.
authors: Zuwhan
authors: Z
authors: Yun
mesh_terms: D000693:Anaerobiosis; D057219:Biofouling / Q000517:prevention & control*; D019149:Bioreactors; D008567:Membranes, Artificial; D010865:Pilot Projects
chemical_list: D008567:Membranes, Artificial
keywords: anoxic gas recirculation system; anoxic membrane bioreactor; fouling