Biochemical treatment system for enhancing total nitrogen removal

Abstract

The invention discloses a biochemical treatment system for enhancing total nitrogen removal. The biochemical treatment system comprises an anaerobic tank, an anoxic tank, an aerobic tank, a rear anoxic tank, a rear aerobic tank and a precipitation and concentration tank which are sequentially communicated. In a treatment method, sewage is introduced into the system from the anaerobic tank, is sequentially delivered through the anoxic tank, the aerobic tank, a slightly-dissolved oxygen tank, a buffer tank, the rear anoxic tank, the rear aerobic tank and the precipitation and concentration tankto be treated and then is discharged; wherein an oxygen elimination tank is arranged in the anaerobic tank, sewage is introduced into the system through the oxygen elimination tank of the anaerobic tank; a sludge reflux pump is arranged at the bottom of the precipitation and concentration tank, and an outlet of the sludge reflux pump is communicated to the oxygen elimination tank in the anaerobictank through a sludge discharge pipe and is used for refluxing sludge at the bottom of the precipitation and concentration tank to the oxygen elimination tank in the anaerobic tank for recycling; a mixed liquid reflux pump is arranged at the tail end of the aerobic tank, and an outlet of the mixed liquid reflux pump is communicated to the front end of the anoxic tank through a reflux channel and is used for refluxing mixed liquid at the tail end of the aerobic tank to the anoxic tank to be quickly mixed with sewage introduced into the anoxic tank.

Description

technical field [0001] The invention relates to the field of sewage treatment, in particular to an enhanced total nitrogen removal biochemical treatment system. Background technique [0002] Domestic sewage treatment national standards and local standards are becoming more and more stringent, and the effluent discharge standards of urban sewage treatment plants have also been increased. Many areas require Class IV or even Class III, and the discharge limit of total nitrogen is required to be 10 mg / L or even 5 mg. / L. As the discharge standards of urban sewage plants in my country have been upgraded to Grade A of the "Pollutant Discharge Standards for Urban Sewage Plants" GB18918-2002, there has been a wave of upgrading and upgrading of sewage treatment plants across the country. Today, areas such as Beijing, Tianjin, Minjiang River and Tuojiang River Basin in Sichuan Province have successively issued very strict local pollutant discharge standards, and the main indicators a...

AI Technical Summary

Problems solved by technology

The A2 / O process has a wide range of applications, but there are also many problems. Due to the contradiction between denitrifying bacteria, phosphorus accumulating bacteria and nitrifying bacteria, the efficiency of denitrification is greatly reduced, especially in today's high-standard Under the requirements of effluent water quality, it is difficult to ensure the stability of effluent total nitrogen up to the standard

The conventional A2 / O process is generally anaerobic / anoxic / aerobic, and phosphorus accumulating bacteria preferentially use the carbon source in the influent, which makes the carbon source insufficient in the subsequent anoxic denitrification process and affects the denitrification effect

[0005] At the same time, for low-carbon source sewage, the content of organic matter in the influent is low, which cannot provide enough electrons for the denitrification and denitrification process of denitrifying bacteria, resulting in a decrease in the removal rate of total nitrogen.

Therefore, when treating sewage with a low concentration of organic matter, sewage treatment plants often need to supplement external carbon sources, and the increase in carbon sources will greatly increase the operating costs of sewage treatment plants

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