【作者】 刘志强；

【导师】 黄廷林；

【作者基本信息】 西安建筑科技大学 ， 环境工程， 2010， 博士

【摘要】 本论文是西部建筑科技重点实验室(筹)开发基金项目“分散聚居区污水处理及资源化技术研究”的专题之一。针对分散聚居区污水的特点,采用缺氧／好氧膜生物反应器试验装置,就其处理分散小区污水的工艺影响条件、膜污染及脱氮性能、处理试验及应用开发进行了研究。缺氧／好氧膜生物反应器(A/O-MBR)是缺氧／好氧处理工艺与膜分离技术结合而成的新型污水处理及回用工艺。为使系统取得良好的运行效果,需找出影响试验运行的主要因素,并确定主次关系及最佳条件。本研究采用四组平行小试系统进行了正交试验,确定了影响系统运行的主要因素及优化条件。从影响膜污染程度和系统脱氮性能的影响分析,得出了各因素的影响力排序为：SRT>IR>Q气>VA／VO。为了探讨运行条件对A/O-MBR系统膜污染及系统脱氮性能的影响,利用小试装置在优化条件下进行了运行试验。研究了污泥停留时间(SRT)与MBR之间的关系,探讨了其影响膜污染的实质原因。将四组反应器的SRT按低、中、高水平分别设为5d、30d、90d和180d。通过观察各SRT下反应器的膜污染程度,对比得出中水平SRT(30d)时污染最轻。同时,根据各SRT下的混合液性质特征、混合液各组分(悬浮固体、胶体、溶解物)对膜污染的贡献率以及临界通量测定值,分析得出溶解性微生物产物(SMP)是影响膜污染的最直接、单一的污泥性质因素,是SRT影响MBR运行效果的实质原因。根据膜污染情况,将其划分为初始污染、缓慢污染和污染跃升三个阶段,利用典型过滤机理模型,重点对前两个阶段进行了数值拟合。拟合结果表明,在初始阶段介质堵塞作用在膜污染中占据主导地位,而在缓慢阶段滤饼堵塞作用占据主导地位。同时,研究了SRT和进水C／N比对A/O-MBR系统脱氮性能的影响,并建立了硝化和反硝化的动力学方程,利用PCR-DGGE技术对反应器内的菌落结构进行了分析。结果表明：在达到硝化菌的最小世代时间后,SRT和进水C／N比对反硝化作用的影响较为显著。好氧区比硝化速率和缺氧区比反硝化速率与污泥龄的动力学方程分别为qN=(32.0+5.60θC)／θC和qD=(54.4+3.54θC)／θC。系统不同反应分区在不同SRT条件下的微生物群落结构不同。为了考察A/O-MBR处理分散小区污水的情况及适用性,利用山东省环境工程重点实验室多工艺一体化污水处理设备,对A/O-MBR工艺处理分散小区污水及回用进行了中试试验。研究了A/O-MBR长期运行状况,结果表明,该系统处理出水水质能稳定达到了《城市污水再生利用城市杂用水水质标准》(GB／T18920-2002)中的标准。同时,考察了膜污染情况,对试验用膜进行了四次清洗,并初步得出膜清洗的周期。通过扫描电镜(SEM)对膜丝的污染情况进行了分析。在试验运行的第三阶段,向膜生物反应器中投加PAC,探讨了PAC对系统运行效果及对膜污染的影响。试验结果表明：膜内表面的污染主要为生物污染；膜通量经过10d左右的快速下降后,进入平缓下降阶段,日均下降速率为0.211L／m2·h·d,投加PAC能缓解膜污染,可延长膜清洗周期。同时结合实际工程——青岛流亭机场污水处理站,对A/O-MBR系统进行了考察和研究,结果表明,A/O-MBR工艺适用于分散聚居区的污水处理及回用。为便于实际应用与推广,在试验研究基础上对A/O-MBR进行了开发研究。将A、O两区在空间上进行了合理设计,同时,考虑了两区的体积可调,搅拌、曝气和混合液回流可控,以及能实现抽吸泵自控等因素,设计研制了立式A/O-MBR污水处理装置,并进行了试验研究。结果表明,该装置具有处理效果好、运行稳定,占地面积小以及自控程度高等特点。已申请了发明专利。为了探讨MBR污水处理系统的经济可行性,对MBR系统进行了初步技术经济分析,并对该系统处理污水的成本进行了估算,分析了影响系统运行费用的主要因素,同时,与其他污水处理及回用工艺进行了技术经济比较。更多还原

【Abstract】 The dissertation project was from the foundation item on state key lab of western architecture and technology (cultivating base)-studies on sewage treatment and recycling technology in scattered neighborhoods. Anoxic/aerobic membrane bioreactor (A/O-MBR) was choosed to treat the sewage from scattered neighborhoods, according to whose characteristics. The operating conditions, membrane fouling, denitrification performance and application development of A/O-MBR were studied in the dissertation.Anoxic/aerobic activated sludge process is combined with membrane separation technology to produce a new process namely A/O-MBR system. The key operating conditions on A/O-MBR and their primary and secondary relation should be found, in order to keep the system running well. In this dissertation,4 parallel bench scale equipments were established to make orthogonal tests. Through observing membrane fouling and denitrification performance under different conditions, the primary and secondary relation of them is:sludge retention time (SRT)>Internal reflux ratio (IR)> aeration intensity (Qair)>the volume ratio of anoxic and aerobic zone (VA/VO).The relationship between SRT and MBR was studied by 4 bench scale equipments above. The essential reason on membrane fouling was revealed. The SRT of 4 parallel test was 5d,30d,90d and 180d respectively from low to high level. By contrast the fouling degree was least under middle level SRT (30d) for the parallel tests of A/O-MBR. The mixed liquor characteristics, contribution rate of each mixed liquor component (suspended solid, colloid and solute) to fouling and critical flux were detemined under different level SRT. Finally, it was known that soluble microbial products (SMP) was the most critical factor to impact on membrane fouling. The entire fouling process was divided into three stages namely initial, slow and rapid. Numerical fitting was done to initial and slow fouling stage by filter mechanism models. According the fitting results, medium clogging and cake blockage played a major role in initial and slow fouling separately.Meanwhile, using 4 bench scale equipments, it was studied that the denitrification performance of A/O-MBR was affaced by SRT and the ratio of carbon and nitrogen source in influent (C/N). Kinetic equations of nitrification and denitrification were constructed. Colony structures were analyzed in the bioreactor by PCR-DGGE technology. From the experimental results, When the nitrification bacteria reach the minimum generation time, the effect of SRT and influent C/N on denitrification are more significant. The kinetic equation was qN= (32.0+5.60θC)/θC between nitrification rate and SRT, while it was qD= (54.4+3.54θC)/θC between denitrification rate and SRT. The colony structure in the bioreactor was different with other under each SRT.To investigate the applicability and the condition of dispersed wastewater treatment by A/O-MBR, multi-process integrated wastewater treatment equipment in key laboratory of environmental engineering in shandong province was used. A pilot study on A/O-MBR process as a wastewater treatment and reuse technology in the scattered residential districts is conducted. Long-term operating conditions of A/O-MBR is studied, whose effluent quality met the standards of GB/T18920-2002. Meanwhile, in order to investigate the membrane fouling, four-time washing of membrane was gone, and the condition of membrane fouling was analyzed by SEM. Through this research, the periodic cleaning of the membrane is drawed preliminary. PAC is dosed in membrane bioreactor in the third phase of the pilot, and the operation effect was discussed. The results showed that:fouling in membrane surface is mainly biological pollution; After rapid decline of 10 days, flux entered gently downward phase, and average daily drop rate is 0.211 L/m2·h·d; PAC dosage can extend cleaning cycles. The project of sewage treatment in Qingdao Liuting International Airport is studied and researched. The results show that, A/O-MBR process is fitted for a wastewater treatment and reuse in the scattered residential districts.To facilitate practical application and popularization, the spatial arrangement of anoxic zone and aerobic zone was redesigned. And the operational effect of this system was investigated. The results showe that the reactor have many characteristics, such as good treatment effect, small occupation of land, the volume of anoxic zone and aerobic zone can be easily adjusted, and the pumping time can be controlled automatically. The equipment has been applied for patent. The preliminary technical and economic analysis of MBR system was studied in order to discuss the economic feasibility of this system. Meanwhile, the treatment cost and the major factors affecting the cost of this system were conducted. At last, the technical and economic comparison of this system for other wastewater reuse technology was maked.更多还原