Remove oils, coolants, and suspended solids from manufacturing wastewater efficiently. Our dissolved air flotation systems handle metalworking fluids, tramp oils, and emulsified contaminants with proven performance across automotive, electronics, and general fabrication industries.
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.
Design DAF systems for correct hydraulic loading. Surface area, rise rate and detention time calculations for your flow.
Manufacturing operations across metalworking, automotive assembly, electronics fabrication, textiles, and printing generate complex wastewater streams laden with oils, coolants, suspended solids, and chemical residues. These effluents originate from machining centres, parts washing stations, floor washdowns, and cooling tower blowdown, creating a highly variable pollutant load that demands robust, adaptable treatment solutions.
The characteristics of manufacturing wastewater are uniquely challenging. Tramp oils from leaking hydraulic systems mix with water-based cutting fluids and emulsified coolants, while metal fines, grinding swarf, and suspended particulates add to the solids burden. Solvents, detergents, and alkaline cleaners from degreasing operations further complicate the chemistry. Batch discharge patterns—common in small-to-medium fabricators—produce significant flow and load variations that stress conventional treatment plant designs.
Regulatory pressure continues to tighten. UK manufacturers must comply with trade effluent consents enforced by water companies, with discharge limits typically set at 15 mg/l for oil and 30-50 mg/l for suspended solids. Larger facilities and water-stressed regions increasingly face zero liquid discharge (ZLD) targets, requiring advanced treatment processes that recover water for reuse and minimise liquid waste sent off-site. DAF systems sit at the core of these solutions, delivering reliable removal of oils and solids at a fraction of the footprint of conventional clarifiers.
| Parameter | Typical Range | DAF Removal Efficiency |
|---|---|---|
| Free Oil | 50 - 500 mg/l | 95 - 99% |
| Emulsified Oil | 20 - 300 mg/l | 80 - 92% |
| TSS | 100 - 2,000 mg/l | 85 - 95% |
| COD | 300 - 3,000 mg/l | 45 - 60% |
| pH | 6.5 - 11.0 | Neutralisation required pre-DAF |
| Heavy Metals (as hydroxide precipitate) | 5 - 100 mg/l | 70 - 85% |
Free-floating tramp oil is removed first via belt or tube skimmers, preventing it from emulsifying downstream and reducing DAF chemical demand.
Batch discharges are blended in an equalisation tank to dampen flow and concentration peaks, ensuring stable DAF feed conditions.
pH adjustment, coagulant addition (PAC or ferric), and emulsion-breaking chemistry prepare the wastewater for effective bubble-particle attachment.
Micro-bubbles (20-50 microns) attach to conditioned particles and oil droplets, lifting them to the surface as a concentrated sludge blanket for removal.
Multimedia or bag filtration polishes the DAF effluent, removing residual fine solids and ensuring compliance with strict discharge or reuse standards.
Stable oil-in-water emulsions from coolants and detergents require targeted demulsifiers or pH adjustment to destabilise droplets before DAF separation.
Free tramp oil separates readily; emulsified oil demands chemical conditioning. Accurate characterisation drives correct sizing and chemical selection.
Abrasive metal swarf and grinding fines require hardened scraper mechanisms and wear-resistant materials to protect DAF internals from erosion.
Intermittent discharge from small shops needs equalisation and automated start-stop DAF controls; large plants benefit from continuous flow designs.
Semi-synthetic and synthetic coolant chemistries respond differently to coagulants. Jar testing confirms the optimal chemical programme for each formulation.
DAF pre-treatment protects downstream evaporators and MVR systems by removing oils and solids, enabling zero liquid discharge in water-recovery loops.
Recent indicative proposals for manufacturing DAF installations. Final service planning depends on site conditions, effluent variability, and local installation requirements.
| Flow Rate | 600 m³/day |
| Influent | Free oil 180 mg/l, emulsified oil 85 mg/l, TSS 450 mg/l, COD 1,200 mg/l |
| DAF Model | R&B-DAF-120 with stainless steel contact tank |
| Key Equipment | Tube oil skimmer, 50 m³ equalisation tank, chemical dosing (PAC, anionic polymer, pH), DAF unit, multimedia filter, sludge thickening tank |
| Chemicals | PAC 120 kg/day, polymer 8 kg/day, sulphuric acid 50 L/day |
| Flow Rate | 120 m³/day |
| Influent | Free oil 350 mg/l, TSS 800 mg/l, COD 1,800 mg/l, metal fines |
| DAF Model | R&B-DAF-30 with hardened scraper mechanism |
| Key Equipment | Belt skimmer, 15 m³ balancing tank, pH correction, coagulant / flocculant dosing, DAF unit, bag filter, 5 m³ sludge holding tank |
| Chemicals | Ferric chloride 25 kg/day, cationic polymer 3 kg/day, caustic soda 20 kg/day |
| Flow Rate | 80 m³/day |
| Influent | Emulsified oil 120 mg/l, TSS 250 mg/l, COD 900 mg/l, copper traces 15 mg/l |
| DAF Model | R&B-DAF-20 with integrated pH control |
| Key Equipment | Coalescing pre-filter, 10 m³ equalisation, dual-stage chemical dosing (metal precipitant + polymer), DAF unit, activated carbon polisher, sludge dewatering pack |
| Chemicals | Metal precipitant 18 kg/day, anionic polymer 2.5 kg/day, hydrochloric acid 15 L/day |
Extend coolant bath life by removing tramp oils and suspended fines, reducing fresh coolant purchases and disposal requirements.
Concentrate waste oil into a compact, high-solids sludge, cutting transport and hazardous waste disposal requirements significantly.
Consistently meet water company discharge consents for oil, suspended solids, and COD, avoiding penalties and enforcement action.
DAF units occupy a fraction of the floor space of conventional clarifiers—ideal for retrofitting into crowded shop floors.
PLC-controlled skimming, sludge discharge, and chemical dosing minimise operator intervention and ensure round-the-clock reliability.
Removing tramp oil and metal fines from coolant systems reduces bacterial growth and abrasive wear, extending cutting tool life.
Learn about our complete range of dissolved air flotation systems for demanding industrial wastewater applications treatment across all sectors.
Explore DAF SystemsDetailed technical specifications, sizing charts, and performance data for our standard and bespoke DAF flotation units.
View SpecsSpecialised DAF solutions for removing fats, oils, grease, and suspended solids from food and beverage wastewater.
DAF for Food ProcessingHigh-performance DAF systems engineered for produced water, refinery effluent, and petrochemical wastewater treatment.
DAF for Oil & GasDAF applications in municipal wastewater treatment, including phosphorus removal and primary clarification.
DAF for MunicipalDiscuss your specific requirements with our technical team and receive a tailored proposal for your project.
Contact UsContact Our Engineers to discuss your manufacturing wastewater treatment requirements and receive a customised DAF proposal tailored to your specific effluent profile.
General industrial manufacturing effluent — metal finishing, paint, automotive, plastics, electronics — demands chemistry-resistant DAF design.
Latex / acrylic emulsions: cationic polyamine 50–150 mg/L breaks emulsion. Heavy metals (Pb, Cr) precipitated by lime/NaOH to >8.5 pH. DAF removes precipitated solids.
Pre-treated rinse water (post pH adjustment + hydroxide precipitation). Ferric or alum 100–300 mg/L for floc formation; high polymer load 3–8 mg/L.
Detergent, surfactant, oil, metal particulate. Demulsifier dose 10–40 mg/L; ferric 100–300 mg/L; pH neutral. DAF removes 90–98% of oil + suspended solids.
Complex chemistry: copper, fluoride, organics. Pre-treat with selective precipitation; DAF as polish step. Materials: PVDF or PP plate in saturator due to fluoride aggression.
SS316L for typical industrial. Duplex for high-chloride (galvanising, hot-dip). PP / FRP for aggressive acidic chemistry. PVDF for HF / fluoride.
Industrial pre-treatment to sewer requires meeting trade-effluent consent limits. DAF + coagulation typically delivers BOD <500, TSS <200, FOG <100, pH 6–10.
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Our expertise spans multiple industries with sector-specific water treatment solutions.