Urban sewage treatment method and system

Abstract

The invention provides an urban sewage treatment method and system. The method is used in the sewage treatment system. The sewage treatment system comprises a sewage regulating tank, a coarse grid, afine grid, a grit chamber, a biochemical tank, a secondary sedimentation tank and a disinfecting tank which are sequentially communicated. The biochemical tank is provided with an EBR filler, a lifting high-efficiency aeration system and a carbon source dosing system. The sewage flows into the coarse grid after being treated by the regulating tank, then flows into the fine grid with suspended solids intercepted by the coarse grid, then flows into the grit chamber with suspended solids intercepted by the fine grid, then flows into the biochemical tank after subjected to grit disposal, then flows into the secondary sedimentation tank after treated by the biochemical tank, then flows into the disinfecting tank after treated by the secondary sedimentation tank and flows into a clean water section after subjected to disinfection treatment by the disinfecting tank. By means of transformation of the treatment process of the traditional urban sewage treatment plant and setting of the biochemical tank, the sewage discharge can reach the class IV water body standard comprehensively and is enhanced to the class IV water body standard comprehensively.

Description

technical field [0001] The invention relates to the field of water pollution control of environmental engineering, in particular to a method and system for treating urban sewage. Background technique [0002] Such as figure 1 with figure 2 As shown, the relatively mature typical sewage treatment process of existing urban sewage treatment plants is: sewage regulating tank→coarse screen→fine screen→grit chamber→biochemical tank→secondary sedimentation tank→coagulation sedimentation tank (optional)→ Cloth filter (optional)→disinfection pool→discharge. The effluent index of this process can only reach the first-class B or first-class A standard of the "Pollutant Discharge Standard for Urban Sewage Treatment Plants" (GB18918-2002), but it cannot reach the effluent index of the water quality standard for Class IV water bodies. Its indicators are shown in Table 1: [0003] Table 1 The maximum allowable emission concentration (daily average value) of the basic control items Uni...

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Problems solved by technology

[0014] So far, no one has proposed a system for comprehensively raising the discharge water of urban sewage treatment plants from the first-level B or first-level A standards of the "Pollutant Discharge Standards for Urban Wastewater Treatment Plants" (GB18918-2002) to the standard for Class IV water bodies method

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