After reaching the national sewage discharge standard, it can be discharged or used as the second water source (reclaimed water), such as greening, irrigation, breeding and so on. Of course, there are also some urban domestic sewage discharged directly, which has great influence on environmental protection and society, and government departments are also taking various measures to actively control it.
Extended data:
The pretreatment process of urban sewage treatment plant usually includes grid treatment, pumping station lifting and sand settling. The purpose of grid processing is to intercept large materials to protect the normal operation of subsequent pump pipelines and equipment. The purpose of pumping water in the pump house is to raise the water head to ensure that the sewage can flow by gravity, and then continue to build various treatment structures on the ground.
The purpose of desanding treatment is to remove sand, stones and large particles carried in sewage, so as to reduce its deposition in subsequent structures, prevent facilities from silting, affect efficiency, cause wear and blockage, and affect the normal operation of pipeline equipment.
Primary treatment process: it is mainly a primary sedimentation tank, which aims to remove suspended solids from sewage as much as possible. Generally speaking, the primary sedimentation tank can remove about 50% of suspended solids and about 25% of BOD5.
Baidu encyclopedia-urban sewage treatment