What DAF removes and how well — 90–99% of TSS and fats/oils/grease, plus phosphorus, metals, colour and algae — and the levers (A/S ratio, coagulation, bubble size) that set it.
The Science Behind Dissolved Air Flotation
Well-designed DAF removes 90–99% of suspended solids and fats, oils and grease, and with coagulation it also strips phosphorus, metals, colour and algae. Removal efficiency is governed by the air-to-solids ratio, coagulation and flocculation, bubble size and hydraulic loading — the parameters our sizing tools quantify.
The levers behind the numbers
95–99% of suspended solids with correct conditioning and A/S.
Fats, oils and grease float readily — often >99% with coagulation.
Ferric/alum co-precipitates P and metal hydroxides for removal.
DAF is the leading way to float algae and bloom organisms.
Air-to-solids ratio sets the lift available for capture.
Overloading the surface cuts capture — size for the duty.
| Contaminant | Typical removal | Notes |
|---|---|---|
| Suspended solids (TSS) | 95–99% | With coagulation/flocculation |
| Fats, oils & grease | 95–99%+ | Floats readily |
| Total phosphorus | 80–95% | With ferric/alum co-precipitation |
| Heavy metals | 70–95% | As hydroxide flocs at correct pH |
| Algae | 90–99% | DAF is the preferred route |
| BOD/COD (particulate) | 40–70% | Particulate fraction only |
Continue across the DAF science series
The micro-bubble DAF overview and hub.
Read MoreCoagulants, polymers, zeta potential and coagulant-free duty.
Read MoreSize a DAF and check A/S, loading and recycle.
Read MoreRise velocities enable 5-15 m/h loading and a compact footprint.
Read MoreOur dissolved air flotation systems range.
Read MoreOur process engineers design dissolved air flotation from first principles — removal efficiency and the full bubble physics — for guaranteed removal at minimum lifecycle cost.
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