What Is the Sequencing Batch Reactor (SBR) Activated Sludge Process? A Detailed Explanation of the Wastewater Treatment Process

A term in the field of environmental engineering; the following definition is from the Environmental Protection Standard of the People's Republic of China, "Environmental Engineering Nomenclature" (HJ 2016-2012).

English: sequencing batch reactor activated sludge process (abbreviated as SBR)

Chinese definition: An activated sludge wastewater treatment method in which the five basic processes of water inflow, aeration, sedimentation, drainage, and standby are sequentially carried out in the same reaction tank (vessel) according to time order, referred to as the SBR method. [1]

SBR is the abbreviation of Sequencing Batch Reactor activated sludge process, which is an activated sludge wastewater treatment technology that operates by intermittent aeration. Its main feature is the ordered and intermittent operation; the core of the SBR technology is the SBR reaction tank, which integrates equalization, primary sedimentation, biodegradation, and secondary sedimentation in one tank, without a sludge return system. It is especially suitable for occasions with intermittent discharge and large flow variations.

In most cases (including industrial wastewater treatment), there is no need to set up a regulation tank; the SVI value is low, the sludge is easy to settle, and generally no sludge bulking occurs; through the adjustment of the operation mode, nitrogen and phosphorus removal reactions can be carried out in a single aeration tank; by using automatic control instruments such as electric valves, level meters, automatic timers, and programmable controllers, the whole process can be fully automated and controlled by the central control room; with proper operation and management, the treated water quality is better than that of the continuous type; when the tank depth is deepened, compared with other methods with the same BOD-SS load, the footprint is smaller; it has strong resistance to shock loads and strong ability to treat toxic or high-concentration organic wastewater.

Background: In recent years, the sequencing batch reactor (SBR) process for treating pig farm wastewater has received increasing attention. Compared with other processes, this process is simple, has less trouble with excess sludge disposal, saves investment, occupies less land, has low operating costs, and is resistant to organic and toxic load shocks. With static sedimentation, the effluent effect is good; anaerobic (anoxic) and aerobic processes alternate, the sludge age is short, and the activity is high, with good nitrogen and phosphorus removal effects. There are also reports of real-time control of the SBR reaction process through oxidation-reduction potential, further improving the removal of nitrogen and phosphorus and saving energy and investment.

1 SBR is suitable for wastewater treatment plants of construction scale III, IV, V and medium and small wastewater treatment stations, and is suitable for the treatment of intermittently discharged industrial wastewater.

5 The design of SBR shall comply with the provisions of HJ 577-2010 and relevant process-type engineering technical specifications. [2]

3 The design parameters of the SBR reaction tank include the number of cycles, the filling ratio, oxygen demand, sludge load, sludge yield, sludge concentration, and sludge age.

4 When SBR is aimed at nitrogen removal as the main goal, a low sludge load and low filling ratio should be selected; when aimed at phosphorus removal as the main goal, a high sludge load and high filling ratio should be selected.

2 The number of SBR reaction tanks should not be less than 2.