Municipal Wastewater Clarifiers
Tighter phosphorus limits, more flow, same footprint. DAF clarifiers engineered for treatment plants, sized from your data — not a catalog.
Where DAF Fits in a Municipal Plant
Municipal plants are under pressure from every direction: lower phosphorus and TSS limits, growing service populations, aging clarifiers and tight capital budgets. Conventional settling clarifiers need large footprints and long retention times, and struggle with fine, light solids like chemical floc and algae.
Dissolved air flotation does the opposite. It floats light solids in minutes, at hydraulic loading rates several times those of settling clarifiers, so it fits where there is no room for another round tank. That makes it a strong fit for tertiary phosphorus removal, lagoon algae removal and waste activated sludge thickening.
Why Phosphorus Limits Are Forcing Upgrades
Nutrient limits in many watersheds have dropped to 1.0 mg/L total phosphorus and below — in some cases well under 0.5 mg/L. Secondary clarifiers alone can't consistently reach those numbers. Plants face compliance schedules, variance requests or water-quality trading costs while they plan upgrades.
The obvious answer — another settling clarifier — often doesn't fit the site or the budget. A DAF clarifier delivers tertiary removal in a fraction of the footprint.
Tertiary Clarification With Micro-Bubble DAF
Chemical precipitation with alum or ferric creates a fine, light floc that settles slowly. Our micro-bubble generator floats it quickly and completely, producing a low-TSS, low-phosphorus effluent ready for filtration or discharge.
- Phosphorus removal of 80–96% with chemical precipitation
- TSS removal of 90–98%, including algae from lagoon systems
- Waste activated sludge thickening to reduce digester and hauling volume
- Designs that follow AWWA, WEF and state design standards
We are straightforward about scope: DAF removes particulate and chemically precipitated phosphorus and solids. It does not nitrify or remove soluble BOD — that remains the job of your biological process. DAF works alongside it, as a compact tertiary or thickening step.
Lagoons, Tertiary Polishing and Thickening
Lagoon systems with seasonal algae blooms use DAF to bring TSS and phosphorus back inside permit. Mechanical plants add DAF as a tertiary step after secondary clarifiers. Larger plants use DAF to thicken waste activated sludge, cutting the volume sent to digesters or haulers. Drinking water utilities use the same technology for algae-laden reservoir intakes.
Typical Municipal DAF Influent
| Parameter | Why it matters | Typical range |
|---|---|---|
| Total phosphorus | Primary driver of tertiary upgrades. | 1–6 mg/L |
| Suspended solids (TSS) | Secondary effluent or lagoon algae. | 10–150 mg/L |
| Algae | Seasonal in lagoons and reservoirs. | Seasonal / variable |
| WAS solids (thickening) | Feed to sludge thickening DAF. | 0.5–1.5% solids |
| Peak flow | Wet-weather peaks set hydraulic design. | 2–3× average |
| Temperature | Cold water affects chemistry and saturation. | 40–75°F |
Ranges from published industry data and our project experience. Your lab analysis sets the real design numbers.
How We Size a Municipal DAF Clarifier
Municipal DAF clarifiers are sized on peak hydraulic flow. In this illustrative example, a 3 MGD plant adds tertiary phosphorus removal with a peaking factor of 2.5.
An FC 550 carries the peak flow and brings total phosphorus to about 0.2 mg/L with chemical addition. Your flow records, permit and pilot or jar-test data set the final design.
FC Maximizer models run from the FC 40 at 22 GPM to the FC 700 at 8,850 GPM with 25% recycle — see the full FC Maximizer sizing table.
| Average daily flow | 3 MGD (about 2,080 GPM) |
|---|---|
| Design peak flow (factor 2.5) | About 5,200 GPM |
| Selected clarifier | FC 550 — 5,500 GPM with 25% recycle |
| Influent total phosphorus | 2.0 mg/L |
| Effluent total phosphorus (90% removal) | About 0.2 mg/L |
| Influent / effluent TSS | 30 / under 5 mg/L |
| Phosphorus removed per year | About 16,400 lb |
Built to Municipal Standards
DAF Corp provides municipal systems for primary clarification, tertiary polishing, algae removal and sludge thickening, built to applicable AWWA, WEF and state design standards. Our FC Maximizer line scales to 11,000 GPM, and we support consulting engineers from preliminary sizing through specification.
Start With a Free Lab Analysis
Send us your flow data, permit limits and a sample of secondary effluent or lagoon water. We jar-test it, and typically within 5–10 business days return a preliminary sizing and budgetary proposal for your engineer. Micro Bubbles. Massive Results.
Request a Lab Analysis
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DAF Corporation works with food processors, municipalities, dairy operations, and industrial facilities to solve complex wastewater challenges. Our process begins with your water — not a catalog.
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