Brewery water-reuse pilot: DAF, MBR, UF and RO at 0.5–1.0 m³/h
A peer-reviewed study operated a modular brewery water-reuse plant for 821 days. The pilot received effluent from a full-scale UASB reactor and combined dissolved air flotation with an MBR, ultrafiltration and reverse osmosis. This is a useful reference for the role of DAF in a multi-barrier reuse train—but the paper does not claim that DAF alone produced the final water quality.
At 0.5–1.0 m³/h, DAF followed by MBR removed 93.6% of COD and reduced BOD₅ to below the 3 mg/L detection limit. UF and RO then produced process water at a total recovery of 0.63 m³ per m³ of brewery wastewater.
Where the DAF sat in the treatment train
The brewery already had a full-scale UASB reactor for high-strength organic load. The pilot was fed with anaerobically treated effluent, not raw brewhouse wastewater.
- Full-scale UASB: upstream anaerobic removal of readily biodegradable COD.
- DAF: mechanical clarification of anaerobic effluent before the membrane bioreactor.
- MBR: aerobic biological polishing and membrane solids separation.
- UF: additional particulate and colloidal barrier.
- RO: removal of dissolved constituents to produce process water.
Published operating facts
| Item | Published result | Correct interpretation |
|---|---|---|
| Pilot flow | 0.5–1.0 m³/h | Hydraulic pilot range; DAF tank dimensions were not published. |
| Operating period | 821 days | Long-term operation, not a short jar test or commissioning snapshot. |
| COD removal | 93.6% | Combined result for flotation plus MBR; not a DAF-only removal percentage. |
| BOD₅ in permeate | Below 3 mg/L; more than 97.6% reduction | MBR permeate after DAF and biological treatment. |
| Process-water yield | 0.63 m³ per m³ wastewater | Yield of the complete DAF–MBR–UF–RO pilot. |
| Final water quality | Drinking-water quality reported | Produced after the complete train; brewing use still requires site-specific food-safety approval. |
Why DAF was useful here
Anaerobic effluent can carry biomass and fine suspended material that raise the solids and colloidal load on an MBR. Clarification ahead of the membrane system helps keep that burden out of the aerobic reactor and membrane zone.
The pilot ran for more than two years, including periods of up to 329 days without chemical membrane cleaning. That stability belongs to the integrated process and cannot be credited to the DAF alone.
What can—and cannot—be transferred
The case supports the process logic UASB → DAF → MBR → UF → RO where high-quality water reuse is required.
It does not provide DAF surface area, recycle ratio, saturation pressure, air-to-solids ratio, chemical dose, inlet and outlet TSS, or sludge concentration. Those values require testing and site-specific design; scaling this pilot by flow alone would not be defensible.
Commercial context
The authors used 75,000 Monte Carlo iterations to model uncertainty in water, wastewater, power, sludge and membrane costs. Reuse was economically viable in 77.2% of simulated cases, with wastewater-disposal cost having the strongest influence. This is a sensitivity result, not a guaranteed payback.
The engineering figures were checked against a peer-reviewed long-term brewery water-reuse study. Brewery and location details are intentionally withheld. Values are reproduced only where published and are attributed to the relevant treatment stage; whole-train results are not presented as DAF-only performance.