Treatment Flow and Technical Scope of the Oxydation Ditch System
with Habuki™ Implementation
Target Facilities and Application Conditions
This technology can be applied to sewage treatment plants that use the Oxidation Ditch method (including POD) or advanced Oxidation Ditch processes, regardless of scale.The application conditions for this technology are as follows:
| Influent Water Quality | Urban sewage primarily composed of domestic wastewater |
|---|---|
| Influent Water Temperature* | 13℃ or higher (annual minimum of monthly average water temperature) |
| BOD/N Ratio at OD Tank Inlet | BOD/N ratio of 3.0 or higher after load reduction is required when applying to advanced OD treatment systems |
| Feasibility Study | A feasibility study must be conducted in advance to evaluate the effectiveness of implementation (e.g., capacity enhancement) |
| Influent Water Quality | Urban sewage primarily composed of domestic wastewater |
|---|---|
| Influent Water Temperature* | 13℃ or higher (annual minimum of monthly average water temperature) |
| BOD/N Ratio at OD Tank Inlet | BOD/N ratio of 3.0 or higher after load reduction is required when applying to advanced OD treatment systems |
| Feasibility Study | A feasibility study must be conducted in advance to evaluate the effectiveness of implementation (e.g., capacity enhancement) |
- If the water temperature is below 13℃, the applicability of the technology will be considered after verifying its performance through a full-scale demonstration test.
Performance
Depends on the annual minimum of the monthly average influent water temperature.
(1) BOD Reduction Rate of This Technology
| BOD Reduction Rate | |
|---|---|
| When water temperature is 16℃ or higher | 48% |
| When water temperature is between 13℃ and below 16℃: | 45% |
| BOD Reduction Rate | |
|---|---|
| When water temperature is 16℃ or higher | 48% |
| When water temperature is between 13℃ and below 16℃: | 45% |
(2) Performance of the Water Treatment System (This Technology + OD Method)
The performance of the water treatment system incorporating this technology is as follows:
| Entire System (This Technology + Oxydation Ditch System) | |
|---|---|
| Capacity Enhancement Performance* | When water temperature is between 16℃ and ℃: 150–190% When water temperature is between 13℃ and below 16℃: 110–120% |
| Energy-Saving Performance* | 20% reduction compared to conventional technologies |
| Sludge Generation Rate | When water temperature is 16℃ or higher: 0.57 When water temperature is between 13℃ and below 16℃: 0.65 |
| Entire System (This Technology + Oxydation Ditch System) | |
|---|---|
| Capacity Enhancement Performance* | When water temperature is between 16℃ and ℃: 150–190% When water temperature is between 13℃ and below 16℃: 110–120% |
| Energy-Saving Performance* | 20% reduction compared to conventional technologies |
| Sludge Generation Rate | When water temperature is 16℃ or higher: 0.57 When water temperature is between 13℃ and below 16℃: 0.65 |
- These are estimated values and may vary depending on specific conditions.
Economic Efficiency – Reduction of Life Cycle Costs
By eliminating the need to expand OD tanks, and reducing maintenance costs through energy savings and lower sludge generation rates, this technology can reduce life cycle costs by up to approximately 22%.
Joint Research with Japan Sewage Works Agency: Introduction to Joint Research| Social Systems | Toshiba (PDF)