【作者】 杜俊；

【导师】 何强； 柴宏祥；

【作者基本信息】 重庆大学 ， 市政工程， 2011， 博士

【摘要】 随着三峡库区经济的迅速发展,其支柱产业榨菜的生产集约化程度越来越高,规模越来越大,生产企业越来越多。但三峡库区绝大部分榨菜生产企业所产生的高盐高氮有机废水未经有效处理便直接排放,导致库区内多条河流的生态系统受到严重威胁,对库区居民生活带来危害。针对传统含盐废水生物处理活性污泥沉降性能差、生物反应器内微生物难以聚集,二沉池泥水分离难等问题,充分利用生物膜固定活性污泥,膜生物反应器能大量聚集微生物而不受污泥沉降性能影响限制等优势,选择具有代表性的榨菜废水为研究对象,开展复合膜生物反应器处理榨菜废水试验研究。通过研究不同膜材质、不同处理工艺对污染物的去除效能的影响,得出了复合膜生物反应器处理榨菜废水的基本运行参数,揭示了盐析对膜污染的影响,探索了膜污染控制及清洗方式,构建了膜通量的数学模型,为缓减膜污染形成、确定膜污染清洗方法、降低MBR处理榨菜废水的运行能耗和提高MBR处理效能提供了理论依据和技术支撑,本文主要研究内容及结论如下:①开展了好氧生物膜-膜生物反应器处理榨菜废水效能试验研究。针对含盐废水生物处理污泥沉降性能差等特点,设计了4组试验研究复合膜生物反应器使用PVDF膜和PP膜处理榨菜废水,在不同进水负荷,常温,盐度为2%～3%,挂膜密度为30%,DO为4mg/L～5mg/L,抽吸泵抽10min停3min,跨膜压差为15KPa的运行条件下,对比使用PVDF膜和使用PP膜的处理效能及膜污染情况。试验结果表明:在常温条件下,MBR采用PVDF膜处理榨菜废水的推荐运行负荷为1.0KgCOD/（m3.d）,出水COD、氨氮和SS浓度均达到国家《污水综合排放标准》（GB8978-1996）的一级排放标准,TP需后续通过化学除磷去除达标;对比使用PVDF膜和使用PP膜时的处理效能及膜污染情况,认为使用PVDF膜组件能更经济有效处理榨菜废水。②开展了缺氧+好氧生物膜-膜生物反应器处理榨菜废水强化脱氮效能试验研究。针对好氧生物膜-膜生物反应器TN去除率低的特点,设计了3组试验,研究了复合膜生物反应器在使用PVDF膜条件下处理榨菜废水,在不同进水负荷,常温,盐度为2%～3%,缺氧区DO为1mg/L、MLSS为2000mg/L,好氧区挂膜密度为15%、DO为3mg/L～4mg/L,膜片区DO为4mg/L～5mg/L、MLSS为6000mg/L,混合液回流比200%,抽吸泵抽10min停3min,跨膜压差为15KPa的运行条件下COD、TN和SS等污染物的去除效果及膜污染情况。试验结果表明:进水容积负荷为0.9KgCOD/（m3.d）时,系统对各污染物去除效果达到最佳,出水COD、氨氮和SS浓度达到国家《污水综合排放标准》（GB8978-1996）的一级排放标准,相对好氧生物膜-膜生物反应器,TN去除率提高了30%。③开展了复合膜生物反应器处理榨菜废水膜污染与控制研究。试验结果表明:高盐条件下,盐析会加剧膜污染速率,温度是影响盐析的主要因素,温度越低,盐析现象越严重,膜污染越严重,且膜污染以不可逆污染为主;DO、污泥浓度、跨膜压差和跨膜压差对膜污染影响效果的顺序是:DO>停抽时间>污泥浓度>跨膜压差,得出了四因素影响膜污染数学模型为:Y=-12.01+133.06A+3.14×10^-4B+2.79C+1.07D-5.51×10^-4AB-8.76×10-15AC-1.13×10-14AD-1.45×10^-4BC-2.5×10^-6BD+0.01CD-64.2A2+4.8×10^-8B2-0.32C2-0.04 D2。通过对该模型的响应面分析,得出了推荐膜污染控制的反应器运行工况为:DO为5mg/L,停曝时间为3.24min,跨膜压差为15.22KPa,污泥浓度为6000mg/L;提出了污染后膜组件的推荐清洗方式:使用水气联合反冲方式进行物理清洗,在物理清洗不能使膜通量有效恢复的情况下需进行化学清洗。推荐的化学清洗方式是0.5%盐酸+0.5%次氯酸钠浸泡,其膜通量能恢复到起始通量的82%。复合膜生物反应器处理榨菜废水效能及膜污染控制的研究成果,将为高盐榨菜废水处理提供一条新的技术路线,为今后膜生物反应器处理榨菜废水的推广与实践提供科学依据与技术支撑,具有重要的现实意义。更多还原

【Abstract】 With the rapid development of the Three Gorges Reservoir economy, the level of intensive producing of its pillar business pickle is getting higher, its scale is getting larger and larger with more and more producing enterprises. But organic wastewater with high concentration of salt and nitrogen from some pickle processing enterprises is discharged directly without effective treatment, as a result, the ecosystems of many rivers in the Reservoir are facing a real danger, and the life of local inhabitants is caused tremendous harm.In response to the features of low treatment efficiency of wastewater with high concentration of salt and poor activated sludge sedimentation, microorganism in Microbial bioreactor is difficult to gather, wastewater and mud in Secondary settling tank is not easy to Separate, the paper took a good use of good advantages of MBR process, which can gather in large numbers of microorganisms and can be unaffected by sludge sedimentation, and the tests were carried out to study on MBR treating pickle wastewater choosing the representative pickle wastewater as research object. It’s mainly to reveal the removal efficiencies of MBR treating pickle wastewater, the effects of salting on membrane critical flux and the control of membrane fouling and cleaning ways, when MBR was used to treat pickle wastewater by studying the removal efficiencies of organic pollutant under the different membrane material and different treating process. A mathematic model of membrane critical fluxes is established to provide theoretical foundations for preventing membrane from fouling, determining fouling membrane cleaning method, reducing energy demands of treating industrial wastewater by MBR and improving treatment efficiency. The contents and main results of the paper are as the follows:①Pickle wastewater was treated by aerobic membrane bioreactor. In response to the features of low treatment efficiency of wastewater with high concentration of salt and poor activated sludge sedimentation, four groups of experiments were designed to study on treating pickle wastewater by mixed MBR using PVDF and PP membrane. On the condition of different feed loadings and normal temperature, and on the condition that the bio-film density was 15%, Salinity was 2%～3%,DO was 4mg/L～5mg/L, suction pumps were operated for 10 minutes and closed for 3 minutes, pressure gradient was 15KPa, compared on the removal efficiency of anaerobic tank effluent and the situation of membrane fouling of PP membrane and PVDF membrane, it’s indicated that the best operating feed loading was 1.0KgCOD/（m3.d） for aerobic membrane bioreactor, and that the effluent concentrations of COD, NH4+-N and SS could meet the first class discharge standard of comprehensive discharge standard of sewage （GB8978-1996）, TP is needed to discharge according to Standard by removal in Chemical methods; PVDF membrane modules could treat pillar wastewater more economically and effectively.②Pickle wastewater was treated by anoxic/aerobic membrane bioreactor. In response to the features of low TN removal rate by anoxic/aerobic membrane bioreactor, three groups of experiments were designed to study on treating pickle wastewater by mixed MBR using PVDF membrane. On the condition of different feed loadings and normal temperature, Salinity was 2%～3% and on the condition that the bio-film density was 15%, DO was 1mg/L and MLSS was 2000 mg/L in the anoxic zone, the bio-film density was 15%, DO was 4mg/L～5mg/L and MLSS was 6000 mg/L in the aerobic zone, the ratio of recycling the mixture was 200%, suction pumps were operated for 10 minutes and closed for 3 minutes, pressure gradient was 15KPa, by studying on removal efficiencies of organic pollutant and situation of membrane fouling, it’s indicated that when the feed volume loading was 1.2KgCOD/（m3.d）, the removal efficiencies of organic pollutant was the best, when the effluent concentrations of COD, NH4+-N and SS could meet the first class discharge standard of comprehensive discharge standard of sewage （GB8978-1996）. Compared to Aerobic biofilm, the persent Removal of TN in Microbial bioreactor is improved 30%.③By analyzing the situation of membrane fouling when operating, it’s indicated that salting-out could accelerate speed of membrane fouling, and that temperature was considered the main factor of effecting salting out, the lower the temperature was, the more salting-out would be, and the worse membrane fouling would be, and that adhering fouling membrane modules was mainly not reversible. The effect of the factors on fouling membrane was aeration strength > cease time > sludge concentration > pressure gradient between diaphragms. It’s also indicated that the mathematic model of the effects of the above 4 factors on membrane fouling was:Y=-12.01+133.06A+3.14×10^-4B+2.79C+1.07D-5.51×10^-4AB-8.76×10^-15AC-1.13×10^-14AD-1.45×10^-4BC-2.5×10^-6BD+0.01CD-64.2A2+4.8×10^-8B2-0.32C2-0.04 D2. By analyzing the model by Response Surface Method, it’s the best operating mode was obtained, and it’s when DO was 5mg/L, cease time was 3.24min, pressure gradient between diaphragms was 15.22KPa, sludge concentration was 6000mg/L. The cleaning methods of fouling membrane modules were also studied, and it’s found that the air-water conbined backwash is the more effective way of physical cleaning, and that chemical cleaning was needed when the physical cleaning can’t recovered effectively. Soaking in 0.5% HCl following 0.5% sodium hypochlorite was the most effective way of chemical cleaning, which could make the flux recovered with 82%.The research achievements of the efficiency and the control of membrane fouling of treating pickle wastewater by Mixed MBR Reactor would provide both a new technical route for the treatment of pickle wastewater with high concentration of salt, and would also provide scientific basis for spread and practice of treating pickle wastewater by Mixed MBR Reactor, which would be of important realistic significance.更多还原