曝气策略对膜面剪切力的影响机制及其优化  

Effect mechanism and optimization of aeration strategy on membrane surface shear stress

作　　者：孙观来 柳蒙蒙[1,3,4] 郁达伟 魏源送[1,2,5,6] 王浩 刘国梁[7,8] 常江 SUN Guanlai;LIU Mengmeng;YU Dawei;WEI Yuansong;WANG Hao;LIU Guoliang;CHANG Jiang(China Laboratory of Water Pollution Control,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;School of Energy and Environmental Engineering,Hebei University of Engineering,Handan 056038,China;YANGTZE Eco-Environment Engineering Research Center,China Three Gorges Corporation,Beijing 100038,China;National Engineering Research Center for Ecological Environment of Yangtze River Economic Belt.Beijing 100038,China;University of Chinese Academy of Sciences,Beijing 100049,China;State Key Joint Laboratory of Environmental Simulation and Pollution Control,Research Center of Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;Beijing Drainage Group Co.,Ltd.,Beijing 100124,China;Beijing Engineering Research Center for Wastewater Reuse,Beijing 100124,China)

机构地区：[1]中国科学院生态环境研究中心,水污染控制实验室,北京100085 [2]河北工程大学能源与环境工程学院,邯郸056038 [3]中国长江三峡集团有限公司长江生态环境工程研究中心,北京100038 [4]长江经济带生态环境国家工程研究中心,北京100038 [5]中国科学院大学,北京100049 [6]中国科学院生态环境研究中心,环境模拟与污染控制国家重点联合实验室,北京100085 [7]北京城市排水集团有限责任公司,北京100124 [8]北京市污水资源化工程技术研究中心,北京100124

出　　处：《环境工程学报》2023年第9期2803-2812,共10页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金资助项目(52170062)。

摘　　要：曝气冲刷是浸没式MBR工艺不同于常规活性污泥法工艺的关键特征,然而现行规范的曝气系统设计与运行比较粗放,缺乏气泡尺寸模拟优化方法。以可直接观测的工程规模(500 m^(3)·d^(−1))膜生物反应器为研究对象,对穿孔管角度进行了优化研究,并用群体平衡模型(Population Balance Model,PBM)模型模拟污泥混合液不同粘度下的内部气泡分布情况。结果表明:穿孔管角度垂直向下、60°、45°、30°、垂直向上在膜面产生的平均剪切力分别为1.74、1.46、1.19、1.38、1.67 Pa,这表明曝气角度最优为垂直向下。0.3%、0.5%和0.8%浓度的羧甲基纤维素钠(Carboxymethyl cellulose,CMC)下产生的平均剪切力分别是1.51、1.92、2.24 Pa,气泡直径逐渐增大。且气泡尺寸越大、流速越大,分布越均匀。基于0.3%、0.5%CMC的速度实验结果与PBM模拟结果基本吻合。该研究结果可为MBR技术的工艺优化和系统控制方法提升提供参考。Aeration flushing is a key feature of the submerged membrane bioreactor(MBR)process that is different from the conventional activated sludge process.However,the current aeration system design and operation guidance are relatively extensive,and there is a lack of bubble size simulation optimization methods.Based on a scale of 500 m^(3)·d^(−1)MBR that can be directly observed as the research object,the angle of the perforated tube was optimized and the Population Balance Model(PBM)was used to simulate the internal bubble distribution of the solution at different viscosities.Results showed that the average shear forces generated by the perforated tube with angles vertically down at 90°,60°,45°,30°,and 0°on the membrane surface were 1.74,1.46,1.19,1.38,1.67 Pa,respectively,which indicated that the optimal aeration angle was vertically downwards.The average shear forces generated at 0.3%,0.5%and 0.8%concentrations of carboxymethyl cellulose sodium(CMC)were 1.51,1.92 and 2.24 Pa,respectively,and the bubble diameter gradually increased.The larger the bubble size was,the faster the flow velocity was,and the more uniform the distribution was.The results of velocity experiments conducted on 0.3%and 0.5%of CMC were consistent with those simulated by the PBM.The research results can provide reference for MBR process optimization and system control method improvement.

关 键 词：膜生物反应器 大气泡曝气 曝气器几何特征 种群平衡模型 流变性 

分 类 号：X703[环境科学与工程—环境工程]