在常规的生物脱氮除磷工艺(A/O工艺)中，生物活性污泥在好氧硝化段和缺氧反硝化段之间回流循环。该污泥由硝化菌、反硝化菌、以及其他多种微生物组成，但由于不同菌群的最佳生长环境不同，之间存在着矛盾.而将MBR法与A/O法相结合后，使得这种复合工艺具有很强的适应能力和抗冲击负荷能力，在去除有机物的同时可以去的良好的脱氮效果，综合了膜分离技术和生物处理技术的优点，使出水水质良好，悬浮物和浊度接近于零。长泥龄的生物膜　为生长缓慢的硝化菌提供了非常有利的生存环境，可以有效地提高硝化效果，使得出水水质优异，操作运行简单，污泥产率低，占地面积小等特点。使其应用范围和规模不断扩大。机物去除和脱氮效果较优,且硝化池和硝化需氧量较低。在A/O系统的好氧池中设置膜组件可以稳定构筑物的出水，还可以提高污水处理构筑物对抗冲击负荷的能力。A/O与MBR工艺的结合特别适合于低碳源的污水处理。
关键字：村镇污水处理系统 ；A/O法 ；MBR法 ；村镇污水特点 ；
The Research and Design of the rural sewage treatment system
Environmental engineering   LENG ji
Tutor: CAO ping ; WU zhi chao

General description of the design: The task of the design is to complete independently the design of rural sewage treatment system , and draw the diagram of process flow, the diagram of layout and so on. The design requirement is according to the characteristics of rural areas, sewage in our country the local climate and terrain and economic situation, then Design a set of suitable for rural sewage treatment project, to guarantee the water quality of the effluent water can reach the national emission standard "urban sewage treatment plant pollutant discharge standard" (GB 18918-2002)  1-B standard. The quality of effluent Sewage are as follow: CODcr :60 mg/l, TN: 20 mg/l , TP : 1.5 mg/l ,NH3-N: 8 mg/l.
National Bureau statistics of China according to the "Regulations" and " the notice of national census of the State Council " the sixth national census conducted in 2010 sixth national census data bulletin: the total population of china is 1370536875.the population of rural area is 674149546 people, accounting for 50.32% of the total population. Learned from the data upon, Most of the population of China's is contribution by rural population. from which we know It plays a vital role in the research and design process of village sewage treatment obviously and the improvement of China's water environment quality.
 In recent years, China's multiple regions have more and more acid rain and the serious water pollution problems. With the area, speed up of the process of industrialization, the contradiction between economic development and population, resources, environment will be more and more outstanding. the rural ecological construction and water environment remediation problems is one of the focal issues generally which should be pay more attention to. The research and design of wastewater treatment technology is the area of town is particularly urgent and necessary.
The characteristics of rural sewage:1.The water discharge of rural is small
The development level of rural industrialization is low, most towns sewage is mainly production wastewater residents, commercial, catering industry sewage and small industrial enterprises. The total amount of water is small, and the sewage is easy biochemical treatment. The volume of sewage in most towns of the 50 ~ 2000m3 / D .but Considering the different degree of development around the village, village sewage discharge and treatment scale mainly in 50 - 5000m3 / d. Wastewater treatment project of small town is still in the initial stage, less than l% sewage been treated in some small towns.
2.The quality and quantity of Water change with seasons and time 村镇污水处理工艺的研究与设计+CAD图纸(2):http://www.youerw.com/huaxue/lunwen_3759.html