The Sequencing Batch Reactor (SBR) is an activated sludge process designed to operate under non-steady state conditions. SBR reactors treat bio-solids, sewage, sludge or other output from aerobic or anaerobic digesters in batches.

The SBR system can be designed with the ability to treat a wide range of influent volumes whereas the continuous system is based upon a fixed influent flow rate. Thus, there is a degree of flexibility associated with working in a time rather than in a space sequence. Advantages includes easy and compact construction, control in time, selection of well settling sludge (‹integrated select.