Plug flow type coupling sewage treatment device and process

Abstract

The invention discloses a plug flow type coupling sewage treatment device and process. The device comprises a reaction device, a water inlet device, a mixed liquid reflux device, a sludge reflux device, a dosing device, an aeration control device and a sludge discharge control device, wherein the reaction device comprises an anaerobic zone, an anoxic zone, an aerobic zone and a solid-liquid separation zone; the water inlet device is connected with the anoxic zone; the dosing device is connected with the aerobic zone; the mixed liquid reflux device is connected with the aerobic zone and the anaerobic zone; the sludge reflux device is connected with the solid liquid separation zone and the anaerobic zone; a stirring device is arranged in the anaerobic zone; a stirring device and immobilizedbiofilm carrier filling are arranged in the anoxic zone; the aeration device and immobilized metazoan carrier filler are arranged in the aerobic zone; and a sludge discharge device is arranged at thebottom of the solid liquid separation zone. The sewage treatment process implemented by using the device can be used for reducing the sludge yield generated by sewage by 30 percent or more; and the process is a two-stage deep treatment process, and can realize deep denitrification without increasing three-stage treatment process.

Description

technical field [0001] The invention relates to the technical field of domestic sewage treatment, in particular to a push-flow coupling sewage treatment device and process. Background technique [0002] Most urban sewage treatment plants in my country adopt the plug-flow activated sludge process and its deformation process, such as A 2 / O process, A / O process, inverted A 2 / O process, etc. The above sewage treatment process has the following problems in the actual operation process: [0003] 1) Large output of excess sludge and difficult treatment and disposal: The activated sludge process commonly used in urban sewage treatment plants has the disadvantage of producing a large amount of excess sludge. The remaining sludge contains a large amount of harmful substances such as refractory organic pollutants, heavy metals and pathogenic microorganisms. It is difficult and costly to treat and dispose of. The cost of treatment and disposal accounts for about 25%-60% of the tota...

AI Technical Summary

Problems solved by technology

Among them, the cost of sludge incineration is too high, and heavy metals affect the safety of agricultural utilization, so most of the remaining sludge is disposed of in landfill

Landfill disposal has such intractable problems as heavy metals, toxic organic substances, etc. polluting land and groundwater, producing toxic and harmful gases, and occupying a large amount of land. It has become a huge problem that plagues urban development and affects the living environment.

[0005] 2) Difficulty adapting to the ever-increasing discharge standards: At present, the relevant state departments are studying and revising the "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB18918-2002), and released a draft for comments, adding "special discharge limits", requiring Special discharge limits are implemented in areas with high density of land development, weak environmental carrying capacity, small environmental capacity, fragile ecological environment or prone to serious environmental pollution problems. For areas with prominent water eutrophication problems, the TN value of the effluent from sewage treatment plants is required. ≤10mg / L

The total nitrogen in the effluent of the activated sludge process commonly used in urban sewage treatment plants is usually between 15 and 20 mg / L, which cannot meet the requirement that the total nitrogen in the effluent is less than 10 mg / L

Adding a tertiary treatment process (such as reverse digestion filter plus carbon source), not only increases the occupied area, but also increases investment and operating costs, which is difficult to implement

In particular, it is even more difficult to carry out upgrading and transformation of sewage treatment plants that have been built and operated due to factors such as the inability to add new land and the inability to stop production and transformation of existing processes.

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