The Orbal® multichannel oxidation ditch from Siemens, as a complete mixed, looped reactor system, is well-suited for conventional activated sludge, advanced secondary sludge treatment, simultaneous nitrification-denitrification, biological phosphorus removal, and stormwater treatment. The ditch has three concentric channels: the outer channel - an aerated anoxic reactor - where the majority of the process 'work' takes place; the DO of the second channel that operates in a swing mode to vary with daily load conditions; and the last channel, which maintains a polishing mode that removes remaining BOD and ammonia before the flow exits to final clarifiers.
Siemens Water Technologies
www.water.siemens.com