Designed to handle high flow rates with compact footprint, achieving hydraulic loading rates up to 15 m/h depending on application.
Free interactive DAF sizing calculator. Calculate dissolved air flotation surface area, recycle flow, saturator volume, and power.
FOG removal food industry DAF systems for fat oil grease recovery food processing.
DAF systems for oil and gas produced water and refinery wastewater treatment.
DAF systems for food processing wastewater treatment. Efficient FOG removal, suspended solids separation and reliable discharge compliance.
5-10 m/h hydraulic loading for typical industrial applications with moderate flow rates and solids concentrations.
10-15 m/h for demanding applications requiring maximum throughput in limited space.
Up to 70% smaller footprint compared to conventional clarifiers at equivalent capacity.
Multiple unit configurations to match specific flow requirements and space constraints.
Compact footprint reduces building requirements and installation costs.
Smaller equipment size translates to reduced material and installation costs.
Optimised design minimises energy consumption per m³ treated.
Compact units fit into existing facilities with minimal modifications.
Dissolved Air Flotation is a physico-chemical separation process that removes suspended solids, oils, greases, and colloidal matter from wastewater. Pressurised water saturated with air is released into the flotation zone, generating microbubbles that attach to flocculated particles and float them to the surface as a concentrated sludge blanket. The clarified water exits below the floating sludge layer.
Recycle stream pressurised to 4-6 bar in a saturation vessel with optimised retention time.
Pressure release through proprietary nozzles generates 20-80 µm bubbles with high attachment efficiency.
Rising velocity of bubble-particle agglomerates exceeds settling velocity, forcing separation.
Mechanical scrapers or hydraulic suction systems continuously remove concentrated float.
| Hydraulic Loading | 5 – 15 m³/m²/h |
| Solids Loading | Up to 15 kg SS/m²/h |
| Air-to-Solids Ratio | 0.02 – 0.1 kg air/kg SS |
| Recycle Ratio | 10 – 50% of influent flow |
| Flotation Zone Depth | 1.5 – 3.0 metres |
| Retention Time | 10 – 30 minutes |
| Drive Power | 0.37 – 2.2 kW (scraper mechanism) |
| Construction | SS304, SS316L, or carbon steel with epoxy coating |
95 – 99% suspended solids reduction depending on flocculant selection and upstream conditioning.
>98% oil and grease removal for emulsified and free-floating hydrocarbons.
40 – 70% COD removal depending on solids fraction and coagulant optimisation.
Complete dissolved air flotation systems for industrial and municipal applications.
View PageHydraulic loading is one of three critical DAF design parameters — alongside A/S ratio and contact time.
Hydraulic loading rate (HLR) = (Q + recycle) / cell surface area, in m³/m²·h or m/h. Determines whether bubble-floc complexes have time to rise before exit.
Bubble-floc complex must rise faster than the downward water velocity. HLR < rise velocity. Bubble-only rise: 6–15 m/h; bubble-floc complex: 8–30 m/h.
Algal water treatment: 8–12 m/h. Municipal primary: 5–8 m/h. Industrial oily: 4–6 m/h. Sludge thickening: 3–5 m/h.
Plug-flow ideal; short-circuiting (T₁₀/T < 0.4) means actual contact time is much less than theoretical. CFD verification recommended for new designs.
Diurnal flow peaks of 1.5–2.5x average shift HLR upward. Size for peak or provide equalisation. Some plants split flow across multiple DAF cells.
HLR sensitivity test in pilot: vary flow from 50–150% of design HLR and measure effluent TSS. Identifies safe operating window.
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