Method of secondary sedimentation tank in sewage treatment by replacing biochemical method and structure of method

Abstract

The invention relates to a method of a secondary sedimentation tank in sewage treatment by replacing a biochemical method and a structure of the method. The structure comprises a lateral flow sedimentation tank and an air flotation tank, and is characterized in that the method specifically includes the following steps that: (1) effluent water from a biochemical tank enters into the lateral flow sedimentation tank, large-particle sludge particles are rapidly separated in a solid-liquid separation component, and precipitated sludge flows back to a front end biochemical tank; (2) the effluent water from the lateral flow sedimentation tank is quickly separated from small-particle sludge and scum on the water surface through the air flotation tank, and the sludge and the scum are removed. The hydraulic retention time of the secondary sedimentation tank water is greatly shortened, the occupied area is saved, the problem of floating sludge commonly existing in the secondary sedimentation tankis solved, and the effluent water quality is guaranteed. The method can be used for upgrading the standard of sewage treatment plants and for building new sewage treatment plants.

Description

technical field [0001] The invention relates to the field of water treatment, in particular to a method and structure for substituting a biochemical sewage treatment secondary sedimentation tank. Background technique [0002] As an important part of the biochemical activated sludge sewage treatment process, the secondary settling tank is mainly used to realize the separation of mud and water, to clarify and concentrate the mixed solution, and then to return the sludge to ensure the concentration of activated sludge in the whole system, and its working effect It will directly affect the effluent water quality and return sludge concentration of the activated sludge system. [0003] At present, the commonly used pool structures of secondary sedimentation tanks are divided into advection type, radial flow type, and vertical flow type, all of which generally have a long hydraulic retention time (4-6hr), which is likely to cause sludge denitrification to generate nitrogen, or anae...

AI Technical Summary

Problems solved by technology

[0003] At present, the commonly used pool structures of secondary sedimentation tanks are divided into advection type, radial flow type, and vertical flow type, all of which generally have a long hydraulic retention time (4-6hr), which is likely to cause sludge denitrification to generate nitrogen, or anaerobic metabolism. produce a lot of H 2 S, CH 4 and other gases, making the air bubbles attach to the sludge flocs, causing the sludge to float

On the one hand, the current urbanization process in the country is fast, and it is difficult for most sewage treatment plants to acquire land for expansion, which makes the problem of limited land occupation for standard upgrading and capacity expansion; on the other hand, excessive hydraulic retention time in sedimentation tanks can easily cause sludge to float , causing the effluent SS to exceed the standard

These factors have seriously restricted the process of standard upgrading and transformation of sewage treatment plants, and it is difficult to ensure that the effluent can meet the standard stably

Images