What is SBR?

SBR is short term of Sequential Batch Reactor. SBR recognize as one of the economic design of wastewater treatment plant due to land area and structure cost saving. However, decisions should not be based solely on economics but should also include process flexibility, ability to meet permit limits, and long-termviability.

SBR is an activated sludge process. Common of SBR process were illustrated as below:

 

There are 4 main stage completing SBR process for wastewater treatment.

Stage 1:
Filling stage – Wastewater will enter into reactor tank (normally square size) after primary treatment (primary screening, secondary screening, grit and grease removal).

Stage 2:

Reaction stage – The wastewater will be air-injected (aerated) and mixed, purposely to provide oxygen to microbe (endogenous Heterotroph bacteria and protozoan) which decompose organic matter (BOD components) for growth in aerobic conditions. The existence of microbe may observe virtually through brownish water (suspended solid/sludge) during this stage.

In Malaysia, Stage 1 and stage 2 were preceded parallel.

Stage 3:
Settling stage – Filling and reaction (aeration and mixing) no more in place during this stage. The condition allows stagnant water whereas suspended solid will settle bottom inside the reactor. Two obvious liquid layer existed which top is clear treated water and bottom is sludge. By completely assuming here, more compacted sludge is flocculated and ready for return or waste.

Stage 4:

Decanting stage – Removing clear treated water (effluent).