中格栅—提升水泵—细格栅—调节池—平流式沉砂池—CASS池—二沉池—浓缩池—清水池[3]（注：由SBR工艺特点可不设初沉池、二沉池，但处理流程没有一个构筑物可大量去除水中SS，则考虑了在生化反应池之后加一个二沉池有效的去除SS和生化池会产生的活性污泥。二沉池产生的污泥可回流到生化池，提高了其污泥负荷，这样可达到一个良性循环。）
整个设计的概预算包括固定资产（土地费+构筑物工程造价+土建费+设备费用），运行费用（动力费+工资福利+生产用水费+运输费用+文护文修费），总投资费用为6307.9万元，其中土地费占用加大，运行费用为240.6万元。6888
关键字： 城市污水；高可生化性；SBR；间歇操作；经济；CASS
A design of SBR biochemical process for urban sewage treatment
The instruction of the design: This design is aimed at urban sewage, the urban sewage contains high organic matter, such as starch, protein, fat, etc., as well as nitrogen, phosphorus and inorganic substances, in addition, it also contains more suspended solids, pathogenic microorganisms and its high biological availability. Currently, the traditional activated sludge process, delay aeration activated sludge process, SBR, AB, UNITANK and oxidation ditch process, AO and A2O, etc are widely used water pollution treatment technology of urban wastewater in China. This design is mainly about SBR biochemical process for urban sewage treatment. Practice has proved that SBR - sequencing batch type activated sludge process is one of the most economic and effective urban sewage treatment technology, which is also suitable for China's national conditions that efficient, economic and reliable enough.
The SBR process, namely sequencing batch reactor activated sludge process. The intermittent operation is its main feature and the called intermittent performances in space and time, but for a single SBR reactor, no space control barriers, just limited in time control .With the exchange of skills to meet the requirements of multiple functions, so the SBR showed flexibility in a higher level.
In it process there is a cycle pided into five stages: inflow, reaction, precipitation, effluent and statement.
By comparing the characteristics of different derivative technologies such as ICEAS, UNITANK, MSBR, CASS, etc. Finally I decide to select CASS as the body structure of the design. That called cyclic activated sludge process—CASS [1] is a process combined variable volume activated sludge process and the principle of biological selector together organically. With simultaneous nitrogen and phosphorus in sequencing batch reactor that aeration – non aeration of intermittent activated sludge treatment process.
It is based SBR technology, and then pided the reactor into a pre reaction area and the main reaction area.
In the pre reaction zone: In front of this part there is equipped with the biological selection area, the biological selector using the substrate as a driving force to cultivate zoogloea bacteria selectively, making its become dominant fungi in the aeration tank, so the waste water can straightly flow into the pre reaction zone, also it plays the role of the biological selector to avoid the sludge filamentous expansion effectively. In addition, the anoxic condition can enhance the removal efficiency of degradation-resistant organic compounds.
In the main reaction zone: the microorganisms will transfer most of soluble organic matter that is adsorbed in sewage quickly through enzyme, then experience a fast accumulation process accompany high load matrix, and then in the main reaction zone through a low load of substrate degradation processes along with the pool, accomplishing the degradation of organics in the wastewater.
CASS process ‘characteristics are as follows:
1. It controls anoxic condition in the pre reaction zone of CASS reaction pool; therefore, it can improve the removal efficiency of degradation-resistant organic compounds. 城市污水SBR生化处理工艺设计+CAD图纸+答辩PPT(2):http://www.751com.cn/huaxue/lunwen_4497.html