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Updated: Jun 6, 2026

A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities
Published on: December 25, 2015
Integration of nitrification and denitrification by combining anoxic and aerobic conditions in a membrane bioreactor
Jianfeng Li1, Fenglin Yang, Dieudonné-Guy Ohandja
1Institute of Environmental Science and Engineering, Nanyang Technological University, Singapore 637723, Singapore. lijf@ntu.edu.sg
Abstract:
A membrane bioreactor (MBR) was developed to achieve nitrogen removal by combining nitrification and denitrification conditions in one reactor. The activated sludge was alternated between aerobic and anoxic conditions using peristaltic pump. The biomass concentration and floc morphological properties were observed to be similar in anoxic and aerobic compartments. However, the homogeneous properties of the activated sludge did not lead to the failure of oxygen gradient formation in the reactor. Due to the position of the air diffuser, an anoxic compartment at the bottom and an aerobic compartment in the upper part of the reactor were formed after 40 days. The average total nitrogen (TN) removal efficiency was then observed to increase to 77%. The microbial characterization using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis, as well as the specific nitrogen utilization rate measurements, indicated that the nitrogen removal in the reactor occurred via nitrification and denitrification processes.
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