Sequencing batch reactor

SBRs treat wastewater such as sewage or output from anaerobic digesters or mechanical biological treatment facilities in batches.

This helps to mix the incoming influent and the returned activated sludge (RAS), beginning the biological digestion process before the liquor enters the main part of the tank.

There are five stages in the treatment process:[1] First, the inlet valve is opened and the tank is filled, while mixing is provided by mechanical means, but no air is added yet.

An anoxic SBR can be used for anaerobic processes, such as the removal of ammonia via Anammox, or the study of slow-growing microorganisms.

The quantity or “age” of sludge within the tank is closely monitored, as this can have a marked effect on the treatment process.

This has a piped connection to a lagoon where the final effluent is stored for disposal to a wetland, tree plantation, ocean outfall, or to be further treated for use on parks, golf courses etc.

SBR treatment systems that cannot cope up with a sudden constant increase of influent may easily be converted into EA plants.

Extended aeration plants are more flexible in flow rate, eliminating restrictions presented by pumps located throughout the SBR systems.