The Oxidation Ditch (OD) system is a modified form of the activated sludge extended aeration system. OD system is a mechanized secondary treatment system which are tolerant of variations in hydraulic and organic loads. The OD system can be easily adjusted to meet most combinations of incoming sewage and effluent standards. This system achieves both high BOD reduction and nutrient removal.
The OD system consists of a “ring or oval shaped channel” equipped with mechanical aeration devices. After the screening & grit removal, wastewater enters the ditch is aerated and circulated. The hydraulic circulation inside the ditch/channel allow the MLSS to be circulated back to the influent channel without required any MLSS pumping system.
Advantages of Oxidation Ditch (OD) system:
- It can be easily maintained.
- It is hard to be effected by load fluctuations and forms only a little sludge.
- OD can be easily controlled by changing the rotation of the rotor and the dipping depth.
- It requires relatively little energy as the rotor is operated efficiency.
- It can perform nitrification and denitrification easily.