What should be paid attention to in denitrification of SBR process?

First, understand the principle of SBR.

SBR is the abbreviation of sequencing batch activated sludge process, and it is an activated sludge wastewater treatment technology with intermittent aeration.

I. Principles

sequencing batch reactor activated sludge process

Environmental engineering terms, the following definitions come from China People's Congress and National Environmental Protection Standard Environmental Engineering Terms (HJ20 16-20 12).

English: sequencing batch activated sludge process

English definition: In the same reaction tank (reactor), activated sludge wastewater treatment method consists of five basic processes: water intake, aeration, precipitation, drainage and standby, which is called SBR method for short. [ 1]

SBR is the abbreviation of sequencing batch activated sludge process, and it is an activated sludge wastewater treatment technology with intermittent aeration. Its main feature is orderly intermittent operation. The core of SBR technology is SBR reaction tank, which integrates the functions of homogenization, primary precipitation, biodegradation and secondary precipitation in one tank, and there is no sludge reflux system. It is especially suitable for intermittent discharge and occasions with large flow change.

Two. characteristic

In most cases (including industrial wastewater treatment), there is no need to set up a regulating tank; The SVI value is low, sludge is easy to precipitate, and sludge bulking generally does not occur; Nitrogen and phosphorus can be removed in a single aeration tank by adjusting the operation mode; The application of automatic control instruments such as electric valve, liquid level meter, automatic timer and programmable controller can make this process fully automatic and controlled by the central control room. Proper operation and management, the treated water quality is better than continuous; When the depth of the pool is deeper, compared with other methods with the same BOD-SS load, the area occupied is smaller; Resistant to impact load and strong ability to treat toxic or high-concentration organic wastewater.

Background: In recent years, sequencing batch reactor (SBR) has been paid more and more attention to treating pig farm wastewater. Compared with other processes, this process has the advantages of simple process, troublesome disposal of excess sludge, less investment, less land occupation, low operating cost, flexible operation mode, good effluent effect, short sludge age and high activity. Moreover, it is reported that the progress of SBR reaction is controlled by redox potential in real time, which further improves the removal effect of nitrogen and phosphorus.

3. The denitrification process mainly relies on nitrifying bacteria to convert ammonia nitrogen into NO3 salt under aerobic conditions, and then denitrifying bacteria to convert NO3 salt into N2 under anaerobic conditions to remove ammonia nitrogen.

Therefore, it is necessary to control the time of anaerobic stage to ensure the denitrification process.