How is the domestic sewage in the city treated?

Common treatment methods of municipal domestic sewage;

1, using ordinary aeration method to treat municipal domestic sewage. Ordinary aeration method appeared earlier. This method not only has a good effect of treating domestic sewage, but also has a large amount of domestic sewage. The sewage treatment plant can build a sludge digester, and the biogas produced by the reaction can be used as energy. In order to achieve the purpose of nitrogen removal, the traditional ordinary aeration method can be solved by reducing the volume load of aeration tank; In order to achieve the purpose of phosphorus removal, an anaerobic zone can be added in front of the aeration tank to solve the problem.

2.SBR is the abbreviation of sequencing batch reactor, and the reactor is the main structure of sequencing batch reactor. The process of reaction and drainage is completed in the reaction tank of sewage, which greatly simplifies the treatment process. In recent years, the sequencing batch activated sludge process has been continuously improved and perfected, and has been widely promoted. It is a widely used sewage treatment process at present.

Sequencing batch activated sludge process is mixed in space, and the push-flow time mode has higher biochemical reaction speed. The process flow of sequencing batch activated sludge process is very simple. Compared with other methods, it has fewer structures, lower construction cost, lower operation cost and lower management cost. The static precipitation method is adopted, which has good separation effect and high effluent quality.

Sequencing batch activated sludge process has flexible operation mode and many treatment processes. Through the same reactor, the sequencing batch activated sludge process can treat wastewater with different properties as long as the operating parameters are changed.

3. AB method is used to treat urban domestic sewage. AB process is based on activated sludge process and two-stage process. AB method is the abbreviation of adsorption-biodegradation method, and it is a new sewage treatment technology. Section A and Section B are isolated from each other and have an independent reflux system, which can ensure that Section A and Section B have different microbial systems and their respective reaction processes.

In stage A, the sludge load is high, only some prokaryotes are suitable for survival, growth and reproduction, and eukaryotes will not be mixed into the sludge, which plays a good buffer role for the impact load of water quality and pH value. A-level process will produce a lot of sludge, and the residual sludge has high organic content.

In the B-stage aeration tank, there are not only commonly used microorganisms, but also many advanced eukaryotic microorganisms with long generations, which can grow and reproduce with low organic matter content.

4. Activated sludge process is used to treat municipal domestic sewage, that is, activated sludge is used to remove organic matter from wastewater. First, the returned activated sludge and sewage enter the aeration tank at the same time, and air is pumped into the aeration tank to fully mix the sewage and activated sludge. Microorganisms in the aeration tank adsorb and decompose the organic matter in the sewage to purify the sewage.

Then, in order to separate the activated sludge from the treated sewage, the mixed liquid enters the secondary sedimentation tank for separation. Finally, the purified water can be discharged to the outside, and part of the separated activated sludge flows back to the aeration tank through the reflux system, and the other part is discharged from the system. The main equipment of activated sludge process is aeration tank and secondary sedimentation tank.