Sequential Batch Reactor (SBR)

The Sequential Batch Reactor (SBR) is a wastewater treatment process that operates in a batch mode, meaning it treats wastewater in sequential cycles or batches rather than continuously. It combines biological treatment, settling, and decanting stages within a single reactor.

Process Steps

Filling: The reactor is fill with wastewater to be treat. The influent wastewater may undergo preliminary treatment processes, such as screening or grit removal, before entering the SBR.
Reacting: Once the reactor is fill, the treatment phase begins. Aeration and mixing are initiating to provide oxygen and promote the growth of microorganisms. The microorganisms metabolize and break down organic matter present in the wastewater through biological degradation.
Settling: After the treatment phase, the aeration and mixing are stopping, allowing the solids to settle to the bottom of the reactor. The settle solids form a sludge layer, while the clarified water remains above the settle sludge.
Decanting: The clarify water, or effluent, is slowly decant or drawn off from the top of the reactor. Care is taken to avoid disturbing the settled sludge layer at the bottom. The decant effluent is typically discharge or subjected to further treatment processes if necessary.
Sludge Handling: The settled sludge is retain in the reactor for further processing. The sludge may undergo processes such as thickening, dewatering, or digestion to reduce its volume and stabilize it for subsequent disposal or reuse.
Repeat Cycle: After decanting, the reactor is ready for the next cycle. The reactor is emptied of treat effluent and prepared for the next batch of influent wastewater. The sequence of filling, reacting, settling, decanting, and sludge handling is repeating in subsequent cycles.

Significance & Advantages

Flexibility : The batch mode operation allows for flexibility in handling variations in wastewater flow and composition. The system can adapt to changes in influent characteristics, making it suitable for small to medium-sized treatment plants.
Energy Efficiency: The SBR process typically operates with intermittent aeration, leading to energy savings compare to continuous aeration in conventional activated sludge systems.
Nutrient Removal: The SBR process can be design to incorporate nutrient removal, including nitrogen and phosphorus, through appropriate process control and additional treatment stages.
Sludge Minimization: The settling and decanting stages in the SBR process promote sludge compaction, reducing the overall sludge production compare to continuous flow systems.

Targeted Impurities

  • COD
  • BOD
  • Nutrient
  • NO2
  • NO3
  • Phosphorus