一体式膜生物反应器膜污染控制的研究
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摘要
一体式膜生物反应器是新型的污水处理工艺，其膜污染控制是一体式MBR应用的关键。本文研究了一体式膜生物反应器中膜污染过程及膜污染控制方法，分析膜污染的机理，探索有利于一体式MBR长期运行的有针对性的膜污染控制技术。研究表明，在一体式MBR膜过滤总阻力中，沉积层阻力占主导地位，是膜过滤过程膜污染的主要来源，长期运行产生的微生物污染也不可忽视，所以一体式MBR的膜污染防治应围绕如何有效控制沉积层的积累和微生物污染；为了优化反应器的水力条件，运行中采用曝气冲刷、间歇抽吸的工作方式，并确定了最佳曝气量、抽吸时间和周期，对减缓沉积层的积累和膜通量的下降具有较好的效果；通过较长时间持续曝气来进行水力清洗在一段时间里控制了污泥向膜面的对流传递过程，而持续的曝气增强了反扩散作用和膜面的传递作用，可以达到一定的恢复通量的效果；对比普通活性污泥法MBR和生物膜MBR，后者可以有效降低膜内外COD的浓度差，控制生物反应器中优势污染物的积累，进而减缓膜通量下降的趋势；对比帘式膜组件和串式膜组件，由于帘式膜组件中空纤维膜丝垂直布置，膜丝之间的混合液可以更好地受到曝气扰动的影响，因此比串式膜组件的抗污染能力要强；针对膜的生物污染，采用次氯酸钠化学清洗的方法效果很好，可以有效去除膜面有机物及细菌污染。
Submerged membrane bio-reactor is a latest wastewater treatment process and membrane fouling control is the key to its spread. In the paper, the membrane fouling process and fouling control methods for a submerged membrane bio-reactor were studied. At first, the mechanism of membrane fouling was analyzed. Then, pertinent membrane fouling control countermeasures to facilitate long-term operation were investigated. The experiments showed that the cake layer resistance was dominant among the total trans-membrane resistance and was the main source of membrane fouling. Microorganism contamination could not be neglected in long-term operation. Therefore, membrane-fouling control should focus on effectively control the accumulation of cake layer and microbes. In order to optimizing the hydraulic condition in the reactor, constant aeration and intermittent pumping was conducted and optimal aeration quantity, pumping
period and pause period were identified which could slow down cake layer accumulation and flux decline. Hydraulic rinse through constant aeration could hold the convection transfer from the sludge mixture to membrane surface and boost up the counter-diffusion and transfer along the membrane surface so that flux could be recovered to a certain degree. By comparing MBR combined with conventional activated sludge system and bio-film system, the latter showed its advantage in reducing the COD concentration difference between the outside and inside of the membrane, resisting the accumulation of dominant contaminants and relaxing the trend of flux decline. As to different membrane module styles, the flat module was more tolerant to membrane fouling than bunch module since the former was easy to have its hollow fibers and mixture among them vibrant with the disturbance of aeration. To control the microbe contamination, chemical cleaning
using sodium hypochlorous had satisfactory result for eliminating organic and bacteria contamination.
Submerged membrane bio-reactor is a latest wastewater treatment process and membrane fouling control is the key to its spread. In the paper, the membrane fouling process and fouling control methods for a submerged membrane bio-reactor were studied. At first, the mechanism of membrane fouling was analyzed. Then, pertinent membrane fouling control countermeasures to facilitate long-term operation were investigated. The experiments showed that the cake layer resistance was dominant among the total trans-membrane resistance and was the main source of membrane fouling. Microorganism contamination could not be neglected in long-term operation. Therefore, membrane-fouling control should focus on effectively control the accumulation of cake layer and microbes. In order to optimizing the hydraulic condition in the reactor, constant aeration and intermittent pumping was conducted and optimal aeration quantity, pumping
period and pause period were identified which could slow down cake layer accumulation and flux decline. Hydraulic rinse through constant aeration could hold the convection transfer from the sludge mixture to membrane surface and boost up the counter-diffusion and transfer along the membrane surface so that flux could be recovered to a certain degree. By comparing MBR combined with conventional activated sludge system and bio-film system, the latter showed its advantage in reducing the COD concentration difference between the outside and inside of the membrane, resisting the accumulation of dominant contaminants and relaxing the trend of flux decline. As to different membrane module styles, the flat module was more tolerant to membrane fouling than bunch module since the former was easy to have its hollow fibers and mixture among them vibrant with the disturbance of aeration. To control the microbe contamination, chemical cleaning
using sodium hypochlorous had satisfactory result for eliminating organic and bacteria contamination.
引文
[1] 王凯军，贾立敏著，城市污水生物处理新技术开发与应用，北京：化学工业出版社，2001
[2] Owen G et al. Economic assessment of membrane processes for water and wastewater treatment. J. Membrane Sci. 1995, 102:77-91
[3] Bailey A D et al. The use of crossflow microfiltration to enhance the performance of an activated sludge reactor. Water Research. 1994, 28 (2): 297-301
[4] 邵刚著，膜法水处理技术，北京：冶金工业出版社，2000
[5] 刘茉娥等，膜技术分离应用手册．北京：化学工业出版社，2001
[6] 黄策等，微孔滤膜及其应用．上海：上海科学技术文献出版社，1980
[7] Rautenbach R, Groschl A. Separation Potential of Nanofiltration Membranes. Desalination, 1990, 77:73-84
[8] 郑领英，我国反渗透膜的研究概况．水处理技术，1984，10(1)：1-5
[9] Kimura S et al. Japan's aqua renaissance '90 projects. Wat. Sci. Tech. 1991, 23:1573-1582
[10] 松本丰，高以恒等，膜科学与技术，1998，18(5)：12
[11] Strathmann H. Water and Wastewater Treatment Experience in Europe and Japan using Ultrafiltration. In: Georges Belfort (ed.). Synthetic Membrane Processes. s. 346. Academic Press, 1984
[12] Adham S et al. Feasibility of the membrane bioreactor process for water reclamation. The First World Water Congress of the International Water Association (IWA)——Wastewater, Reclamation, Recycling and Reuse: 210-220
[13] Cote P et al. Wastewater treatment using membranes: the North American experience. Wat. Sci. Tech. 2000, 41 (10-11): 209-215
[14] Pierre Cote et al. Bubblefree aeration using membranes: process analysis. Journal WPCF. 1988, 60(11): 1986-1992
[15] Brindle Keith, Stephenson T. Nitrification in a bubbleless oxygen mass transfers membrane bioreactor. Wat. Sci. Tech. 1996, 34 (9): 261-267
[16] Livingston A G et al. Detoxification of industrial wastewater in an extractive membrane bioreactor. Wat Sci. Tech. 1996, 33 (3): 1-8
[17] 樊耀波，王菊思，水与废水处理中的膜生物反应器技术．环境科学，1995，16(5)：79-81
[18] 孟耀斌等，分置式膜-生物反应器处理生活污水的抗冲击负荷能力．环境
科学，2000，21(2)：24-27
[19] 李春杰等，焦化废水的一体化—序批式生物反应器处理研究．上海环境科学，2001，20(1)：24-27
[20] 张军等，复合淹没式膜生物反应器脱氮除磷效能研究．中国给水排水，2000，16(9)：9-11
[21] Choo K-H, Lee C-H. Membrane fouling mechanisms in the membrane-coupled anaerobic bioreactor. Wat. Sci. Tech. 1996, 30(8): 1771-1780
[22] Nagaoka H et al. Influence of bacterial extracellular polymers on the membrane separation activated sludge process. Wat. Sci. Tech. 1996, 34(9): 165-172
[23] Choo K-H, Lee C-H. Effect of anaerobic digestion broth composition on membrane Wat. Sci. Tech. 1996, 34(9): 173-179
[24] 鲁学仁，国家海洋局杭州水处理中心膜技术进展概况．水处理技术，1999，25(1)：1-8
[25] R Rautenbach 著，王乐夫译，膜工艺—组件和装置设计基础．北京：化学工业出版社，1998
[26] 陆志福，微孔滤膜及其制备方法和应用范围．净水技术，1982，(1)：46-48
[27] 高以恒，叶凌碧著，膜分离技术基础，北京：科学出版社，1989
[28] 刘茉娥等，膜分离技术．北京：化学工业出版社，1998
[29] 许保玖，龙腾锐，当代给水与废水处理原理(第二版)．高等教育出版社，1999
[30] 李书国，超滤膜的污染原因及清洗方法．食品科学，1999，2：28-30
[31] Sato T, Ishii Y. Effects of activated sludge properties on water flux of ultrafiltration membrane used for human excrement treatment. Wat. Sci. Tech. 1991, 23:1601-1608
[32] J. Hermia, Constant pressure blocking filtration laws: application to power-law non-Newtonian fluids. Trans. Inst. Chem. Eng. 1982,60:183
[33] R.H. Davis, Modeling of fouling of crossflow microfiltration membranes. Separation and Purification Methods. 1992, 21 (2):75-126
[34] K.Stamatakis, C. Tien. A simple model of cross-flow filtration based on particle adhesion. AIChE. 1993, 39:1292-1302
[35] M. Hlavacek, F. Bouchet. Constant flowrate blocking laws and an example of their application to dead-end microfiltration of protein solutions. J. Membrane Sci. 1993, 82:285-295
[36] G.R.H. Belfort et al. The behavior of suspensions and macromolecular solutions in crossflow microfiltration. J. Membrane Sci. 1994, 96: 1-58
[37] 李春杰，一体化膜—序批式生物反应器处理焦化废水的研究：[博士学位
论文]．同济大学，2001．3
[38] Muhammad H. Al-malack et al. Crossflow microfiltration with dynamic membranes. Wat. Res. 1997, 31(8): 1969-1979
[39] 李春杰等，错流膜生物反应器水力清洗特性研究．环境科学，1999，20(1)：57-60
[40] 王亚娥等，膜生物反应器中UF膜过滤阻力影响因素．中国给水排水，2000，16(2)：55-57
[41] Pillay V L et al. Improving the performance of anerobic digesters at wastewater treatment works: the coupled crossflow microfiltration /digester process. Wat. Sci.Tech. 1994, 30(12): 329-337
[42] Strohwald N K H, Ross W R. Application of the ADUF processes to brewery effluent on a laboratory scale. Wat. Sci. Tech. 1992, 25(10):95-105
[43] 黄霞等，膜—活性污泥组合工艺的污水处理特性研究．资源、发展与环境保护，第三届海峡两岸环境保护学术研讨会论文集．1995，95—102
[44] 樊耀波等，膜生物反应器中膜的最佳反冲洗周期．环境科学学报，1997，17(4)：439-444
[45] NAGAOKA H ET AL. MODELiNG OF BIOFOULING BY EXTRACELLULAR POLYMERS IN A MEMBRANE SEPARATION ACTIVATED SLUDGE SYSTEM. WAT. SCI. TECH. 1998, 38(4-5): 497-504
[46] 杨造燕等，膜生物反应器无剩余污泥排放的研究．城市环境与城市生态，1999，12(1)：16-18
[47] Krauth Kh et al. Pressurized bioreactor with membrane filtration for wastewater treatment. Wat. Res. 1993, 27(3): 405-411
[48] Jae-Kim et al. Comparison of ultrafiltration characteristics between activated sludge and BAC sludge. Wat. Res. 1998, 32(11): 3443-3451
[49] 罗虹等，投加粉末活性炭对膜阻力的影响研究．中国给水排水，2001，17(2)：1-4
[50] 王晓琳，膜的污染和劣化及其防治对策．工业水处理，2001，21(9)：1-5
[51] 崔峰等，膜生物反应器运行中的膜污染问题．石油化工环境保护，2000，3：24-26
[52] 刘锐等，一体式膜—生物反应器长期运行中的膜污染控制．环境科学，2000，21(2)：58-61
[2] Owen G et al. Economic assessment of membrane processes for water and wastewater treatment. J. Membrane Sci. 1995, 102:77-91
[3] Bailey A D et al. The use of crossflow microfiltration to enhance the performance of an activated sludge reactor. Water Research. 1994, 28 (2): 297-301
[4] 邵刚著，膜法水处理技术，北京：冶金工业出版社，2000
[5] 刘茉娥等，膜技术分离应用手册．北京：化学工业出版社，2001
[6] 黄策等，微孔滤膜及其应用．上海：上海科学技术文献出版社，1980
[7] Rautenbach R, Groschl A. Separation Potential of Nanofiltration Membranes. Desalination, 1990, 77:73-84
[8] 郑领英，我国反渗透膜的研究概况．水处理技术，1984，10(1)：1-5
[9] Kimura S et al. Japan's aqua renaissance '90 projects. Wat. Sci. Tech. 1991, 23:1573-1582
[10] 松本丰，高以恒等，膜科学与技术，1998，18(5)：12
[11] Strathmann H. Water and Wastewater Treatment Experience in Europe and Japan using Ultrafiltration. In: Georges Belfort (ed.). Synthetic Membrane Processes. s. 346. Academic Press, 1984
[12] Adham S et al. Feasibility of the membrane bioreactor process for water reclamation. The First World Water Congress of the International Water Association (IWA)——Wastewater, Reclamation, Recycling and Reuse: 210-220
[13] Cote P et al. Wastewater treatment using membranes: the North American experience. Wat. Sci. Tech. 2000, 41 (10-11): 209-215
[14] Pierre Cote et al. Bubblefree aeration using membranes: process analysis. Journal WPCF. 1988, 60(11): 1986-1992
[15] Brindle Keith, Stephenson T. Nitrification in a bubbleless oxygen mass transfers membrane bioreactor. Wat. Sci. Tech. 1996, 34 (9): 261-267
[16] Livingston A G et al. Detoxification of industrial wastewater in an extractive membrane bioreactor. Wat Sci. Tech. 1996, 33 (3): 1-8
[17] 樊耀波，王菊思，水与废水处理中的膜生物反应器技术．环境科学，1995，16(5)：79-81
[18] 孟耀斌等，分置式膜-生物反应器处理生活污水的抗冲击负荷能力．环境
科学，2000，21(2)：24-27
[19] 李春杰等，焦化废水的一体化—序批式生物反应器处理研究．上海环境科学，2001，20(1)：24-27
[20] 张军等，复合淹没式膜生物反应器脱氮除磷效能研究．中国给水排水，2000，16(9)：9-11
[21] Choo K-H, Lee C-H. Membrane fouling mechanisms in the membrane-coupled anaerobic bioreactor. Wat. Sci. Tech. 1996, 30(8): 1771-1780
[22] Nagaoka H et al. Influence of bacterial extracellular polymers on the membrane separation activated sludge process. Wat. Sci. Tech. 1996, 34(9): 165-172
[23] Choo K-H, Lee C-H. Effect of anaerobic digestion broth composition on membrane Wat. Sci. Tech. 1996, 34(9): 173-179
[24] 鲁学仁，国家海洋局杭州水处理中心膜技术进展概况．水处理技术，1999，25(1)：1-8
[25] R Rautenbach 著，王乐夫译，膜工艺—组件和装置设计基础．北京：化学工业出版社，1998
[26] 陆志福，微孔滤膜及其制备方法和应用范围．净水技术，1982，(1)：46-48
[27] 高以恒，叶凌碧著，膜分离技术基础，北京：科学出版社，1989
[28] 刘茉娥等，膜分离技术．北京：化学工业出版社，1998
[29] 许保玖，龙腾锐，当代给水与废水处理原理(第二版)．高等教育出版社，1999
[30] 李书国，超滤膜的污染原因及清洗方法．食品科学，1999，2：28-30
[31] Sato T, Ishii Y. Effects of activated sludge properties on water flux of ultrafiltration membrane used for human excrement treatment. Wat. Sci. Tech. 1991, 23:1601-1608
[32] J. Hermia, Constant pressure blocking filtration laws: application to power-law non-Newtonian fluids. Trans. Inst. Chem. Eng. 1982,60:183
[33] R.H. Davis, Modeling of fouling of crossflow microfiltration membranes. Separation and Purification Methods. 1992, 21 (2):75-126
[34] K.Stamatakis, C. Tien. A simple model of cross-flow filtration based on particle adhesion. AIChE. 1993, 39:1292-1302
[35] M. Hlavacek, F. Bouchet. Constant flowrate blocking laws and an example of their application to dead-end microfiltration of protein solutions. J. Membrane Sci. 1993, 82:285-295
[36] G.R.H. Belfort et al. The behavior of suspensions and macromolecular solutions in crossflow microfiltration. J. Membrane Sci. 1994, 96: 1-58
[37] 李春杰，一体化膜—序批式生物反应器处理焦化废水的研究：[博士学位
论文]．同济大学，2001．3
[38] Muhammad H. Al-malack et al. Crossflow microfiltration with dynamic membranes. Wat. Res. 1997, 31(8): 1969-1979
[39] 李春杰等，错流膜生物反应器水力清洗特性研究．环境科学，1999，20(1)：57-60
[40] 王亚娥等，膜生物反应器中UF膜过滤阻力影响因素．中国给水排水，2000，16(2)：55-57
[41] Pillay V L et al. Improving the performance of anerobic digesters at wastewater treatment works: the coupled crossflow microfiltration /digester process. Wat. Sci.Tech. 1994, 30(12): 329-337
[42] Strohwald N K H, Ross W R. Application of the ADUF processes to brewery effluent on a laboratory scale. Wat. Sci. Tech. 1992, 25(10):95-105
[43] 黄霞等，膜—活性污泥组合工艺的污水处理特性研究．资源、发展与环境保护，第三届海峡两岸环境保护学术研讨会论文集．1995，95—102
[44] 樊耀波等，膜生物反应器中膜的最佳反冲洗周期．环境科学学报，1997，17(4)：439-444
[45] NAGAOKA H ET AL. MODELiNG OF BIOFOULING BY EXTRACELLULAR POLYMERS IN A MEMBRANE SEPARATION ACTIVATED SLUDGE SYSTEM. WAT. SCI. TECH. 1998, 38(4-5): 497-504
[46] 杨造燕等，膜生物反应器无剩余污泥排放的研究．城市环境与城市生态，1999，12(1)：16-18
[47] Krauth Kh et al. Pressurized bioreactor with membrane filtration for wastewater treatment. Wat. Res. 1993, 27(3): 405-411
[48] Jae-Kim et al. Comparison of ultrafiltration characteristics between activated sludge and BAC sludge. Wat. Res. 1998, 32(11): 3443-3451
[49] 罗虹等，投加粉末活性炭对膜阻力的影响研究．中国给水排水，2001，17(2)：1-4
[50] 王晓琳，膜的污染和劣化及其防治对策．工业水处理，2001，21(9)：1-5
[51] 崔峰等，膜生物反应器运行中的膜污染问题．石油化工环境保护，2000，3：24-26
[52] 刘锐等，一体式膜—生物反应器长期运行中的膜污染控制．环境科学，2000，21(2)：58-61