Nanobubbles for DAF, coagulation and flocculation
Nanobubble generation during conditioning upstream of coagulation and flocculation. Integration designed to optimise chemical consumption and solids separation in the DAF.
- Application point
- Upstream conditioning
- Initial gas selection
- Air
- Indicators
- TSS, chemicals and sludge
Integration into the treatment line
The stream treated by the generator is introduced before or during water conditioning. Inline or sidestream installation is selected according to process flow, available pressure and mixing conditions.
The objective is to modify the interaction between gas, particles and flocs to improve separation. The nanobubble equipment is coordinated with coagulation, flocculation and the DAF saturation system. Each stage retains a defined hydraulic and process function.
| Aspect | Project criterion |
|---|---|
| Generation | Water flow, pressure and gas supply. |
| Conditioning | Injection point, mixing and contact time. |
| Separation | Solids capture, effluent quality and sludge removal. |
Trial with comparable chemical dosing
The comparison must use a representative feed. Current operation is recorded first, followed by operation with nanobubbles, maintaining traceability of flow, load, pH and dosed products.
Chemical dosing is optimised in steps. Comparing product volumes alone can be misleading if flow or commercial product concentration changes: doses are also expressed as active product mass per volume treated.
| Aspect | Project criterion |
|---|---|
| Quality | Inlet and outlet TSS and turbidity; COD where relevant. |
| Chemicals | Active coagulant and polymer dose, with flow recording. |
| Sludge | Quantity removed, concentration and impact on dewatering. |
| Operation | Energy, gas supply, stability and foaming. |
Operating and cost balance
The benefit is calculated using consumption across the complete line. A change in dosing can alter the amount of chemical sludge and its dewatering and disposal costs.
The economic assessment combines observed savings in chemicals and sludge management, less additional energy, gas and maintenance costs. Outlet quality and treatment capacity form part of the acceptance criteria.
Data for an initial assessment
- Average and maximum flow, and operating hours.
- Feed analysis and required outlet quality.
- Products, commercial concentrations and current doses.
- Coagulation, flocculation, saturation and DAF process layout.
- Sludge management and available line consumption data.