A sequencing batch reactor (SBR) is an activated sludge type wastewater treatment system that can carry out various treatment operations in one tank. It reacts on the principal of fill, React, Settle, Decant and Idle/Waste sludge.

A specific volume of wastewater, called a batch, is first screened to remove larger particles within the water. The reactor is a tank into which air is pumped to ensure that a sufficient supply of oxygen is present for aerobic biochemical processes to occur. The addition of oxygen allows microorganisms to consume dissolved organic matter in the wastewater that are not removed by a screening or settling process. After a specified period of aeration, the wastewater in the reactor is allowed to settle. The sludge that settles on the bottom now primarily consists of the microorganisms that have fed on the organics in the wastewater.

Sequencing batch reactors (SBR) utilize an activated sludge treatment process. After the treated effluent is discharged, all but a small portion of the sludge, which is rich in microorganisms, is removed from the reactor. This helps quickly reestablish a population of microorganisms within the next batch of wastewater delivered to the reactor, reducing the amount of time necessary for treating each batch. Usually more than one reactor is needed so that while one batch of wastewater is being treated, additional flow can be directed elsewhere.

The number of reactors ultimately depends on the expected volume of wastewater flow and the amount of time allowed for treatment of each batch in the reactor. A longer retention period produces less sludge and cleaner effluent.

SBR is a high-performance solution for wastewater treatment that can successfully handle batch and continuous flow operations. It is a proven technology with minimal costs and maintenance requirements.
Due to high versatility and cost-effectiveness, SBR sewage treatment plant is widely used in:

• Personal bungalows, houses and weekend homes.
• Hotels, resorts and holiday homes.
• Hospitals.
• Malls and shopping centers.
• Airports and railway stations.
• Commercial and residential complexes.
• Schools, colleges, and other institutions.
• Small, medium and large manufacturing units.
• Municipal Gardens.
• Sports complexes.
• Other public places.