Oxidation Ditch Biological Treatment
Oxidation ditches represent an advanced form of complete mixing aerotanks, operating under prolonged aerobic conditions with activated sludge in a circulatory movement.
This technology is particularly effective due to its "suspended" biological growth in an oxygen-rich environment, which rapidly destroys organic matter (Biochemical Oxygen Demand, BOD5).
A distinguishing feature of oxidation ditches, unlike traditional activated sludge processes, is the frequent elimination of the need for primary sedimentation tanks as the first treatment stage. Raw wastewater, after preliminary screening and grit removal, can flow directly into the oxygen raceways for processing, simplifying the initial treatment stages and making it particularly suited for domestic wastewater.
While oxidation ditches offer advantages such as simpler management and efficient sludge removal – with only about 15% of the original BOD ending up as sludge, compared to approximately 60% in a packaged plant – they can be land-intensive and incur high electricity costs due to the continuous operation of rotors.
The firm's expertise includes optimizing rotor operation for energy efficiency, implementing diversion basins to prevent washouts during heavy rainfall, and designing multi-ditch configurations for enhanced ammonia removal and operational flexibility.
Furthermore, guidance is provided on the regular attention required for measuring equipment to ensure optimal performance and prevent costly maintenance issues.
The observation that most new treatment facilities are designed as oxidation ditches
underscores a significant industry trend. This highlights that expertise in oxidation ditches is not just about understanding an existing technology, but about being at the forefront of new facility design. Clients pursuing new builds or major upgrades are increasingly considering this option, making this specialization highly valuable and relevant to future projects.