移动床膜生物反应器同步硝化反硝化特性

采用挂膜填料代替传统膜生物反应器(MBR)的活性污泥，构建一种新型的移动床膜生物反应器 (MBMBR)，考察其处理模拟生活污水的效果及同步硝化反硝化(SND)特性.结果表明，移动床膜生物反应器运行67 d，对模拟生活污水表现出良好的去除有机物及同步硝化反硝化能力.进水COD浓度为573.5～997.7 mg/L时，膜出水COD去除率为88.3%～99.2%.进水氨氮浓度为45.5～99.2 mg/L时，膜出水氨氮去除率为72.1%～99.8%，总氮去除率为62.0%～96.3%.批式实验结果表明，生物膜去除总氮的最佳溶解氧浓度为1 mg/L，其中氨氮和总氮去除率分别为100%和60%.生物膜系统内可能存在好氧反硝化现象.DO为3 mg/L且有机碳源充足时，生物膜总氮去除率为99.0%，SND率达到99.8%.扫描电镜对生物膜的观察发现生物膜内部存在着明显的孔隙，有利于溶解氧和有机基质从外界向生物膜内部传递.

Characteristics of Simultaneous Nitrification and Denitrification in Moving Bed Membrane Bioreactor

To investigate the removal efficiency of synthetic wastewater and characteristics of simultaneous nitrification and denitrification (SND) performances, a new type of moving bed membrane bioreactor (MBMBR) had been developed by using carriers instead of activated sludge in membrane bioreactor (MBR). Results showed that good organics removal and SND performances was achieved during the 67 d experimental period. COD, ammonium and total nitrogen removal efficiencies of MBMBR remained 88.3%-99.2%, 72.1%-99.8% and 62.0%-96.3% respectively as influent COD were 573.5-997.7 mg/L and ammonium nitrogen were 45.5-99.2 mg/L. Moreover, batch experiments results showed the optimum DO for nitrogen removal was 1 mg/L, ammonium and total nitrogen removal efficiencies were 100% and 60.0%, respectively. Aerobic denitrification may occur in biofilm system. When DO concentration was 3 mg/L and the organic carbon source was abundant, 99.0% total nitrogen removal efficiency and 99.8% SND efficiency was achieved in batch experiment. The microstructure of biofilm was examined using SEM. Results showed that some cavities were present, which would be favorable to enhance substrate and oxygen to transfer from the bulk to the interior of biofilm.