Dissolved Air Flotation (DAF) Water Treatment for Plastic Recycling
Engineered for harsh industrial wash water in plastic washing lines and PET bottle recycling plants, our dissolved air flotation systems remove up to 98% of total suspended solids (TSS), emulsified glues, oils, and microplastics to deliver crystal-clear water ready for closed-loop recycling.
- Removes up to 98% TSS, microplastics, and dissolved adhesive colloids.
- Closed-loop water recirculation slashes plant fresh water consumption by over 85%.
- Automated chemical dosing and continuous chain-flight surface skimming.
What Exactly is Dissolved Air Flotation (DAF)?
An advanced physical-chemical clarification technology that dissolves compressed air into recycled water under pressure (4 to 6 bar), creating microbubbles (10–30 µm) that float suspended particles to the surface for automated skimming.
Principles of Microbubble Separation
Unlike traditional settling tanks where particles settle under gravity, DAF generates dense microbubble clouds. These bubbles attach to hydrophobic plastic fines, light paper fibers, and flocculated colloids, floating them rapidly to the liquid surface.
- Separation rate is up to 5 times faster than standard gravity clarifiers
- Compact equipment footprint saves valuable workshop area
- Highly effective for low-density solids that refuse to settle naturally
- Produces high-solids sludge that simplifies downstream filter-press cake dewatering
DAF: A Game-Changer for Plastic Recycling Facilities
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85%+ Water Recirculation
Slashes municipal water consumption and effluent discharge volumes through stable closed-loop water recovery.
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Pristine Flake Cleanliness
Continuous removal of suspended organics and fines prevents re-deposition of dirt onto clean plastic flakes.
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Environmental Compliance
Reliably satisfies strict municipal sewer discharge limits for COD, BOD, TSS, and heavy hydrocarbons.
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Automated Chemical Dosing
PLC-integrated metering racks optimize PAC and PAM dosing based on inlet turbidity and flow rate.
How Dissolved Air Flotation Works: Step-by-Step
Raw wash wastewater is first pre-screened to remove heavy macro-contaminants before passing through the four-stage microbubble clarification process.
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Step 1Air Dissolution & Pressurization
A portion of clarified effluent is pressurized to 4-6 bar in a multiphase saturation vessel, dissolving compressed air to saturation point.
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Step 2Microbubble Generation
As saturated water passes through specialized pressure-reducing release valves into the flotation basin, pressure suddenly drops, generating clouds of 10-30 micron microbubbles.
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Step 3Bubble Attachment & Flotation
Microbubbles collide with and adhere to hydrophobic polymer particles and flocculated suspended solids, rapidly lifting them to the surface to form a concentrated sludge layer.
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Step 4Continuous Sludge Skimming
A motorized chain-flight scraper moves across the liquid surface, discharging float sludge into the dewatering hopper while clarified water discharges from submerged effluent weirs.
Cross-Industry DAF Water Clarification Solutions
While proven indispensable for post-consumer plastic recycling, our DAF units are engineered to handle suspended solids and hydrocarbon loads across multiple process industries.
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Plastic Recycling Wash Lines
Clarifies effluent from bottle washing, film recycling, and rigid regrind washing plants.
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Pulp & Paper Mills
Recovers cellulose fibers, removes residual inks, and reduces white water turbidity for complete in-plant recycling.
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Textile & Dyeing Facilities
Separates synthetic dye pigments, chemical finishing agents, and microfibers, substantially dropping effluent color and COD.
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Metal Finishing & Machining
Precipitates heavy metal hydroxides and removes emulsified oils and cutting fluids from electroplating and machining rinse tanks.
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Food & Beverage Processing
Removes fats, oils, and grease (FOG) as well as suspended organic solids from dairy, slaughterhouse, and bakery effluent.
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Municipal Sludge Thickening
Pre-clarifies drinking water reservoirs by removing seasonal algae blooms and serves as an efficient sludge thickening stage.
Dissolved Air Flotation System Specifications
Standard APW series DAF specifications. Custom turnkey systems with integrated coagulant dosing racks, pH balancing, and automated sludge dewatering presses are available upon request.
| Model | Motor Power (kW) | Pump Flow (m³/h) | Treatment Capacity (m³/h) | Tank Dimensions L×W×H (mm) |
|---|---|---|---|---|
| APW-5 | 2.2 kW | 10 m³/h | ~5 m³/h | 2,800 × 1,200 × 1,800 |
| APW-10 | 4.0 kW | 12 m³/h | ~10 m³/h | 3,500 × 1,400 × 2,000 |
| APW-20 | 4.0 kW | 16 m³/h | ~20 m³/h | 4,500 × 1,800 × 2,200 |
| APW-30 | 5.5 kW | 22 m³/h | ~30 m³/h | 5,500 × 2,200 × 2,400 |
Comprehensive Warranty & Engineering Support
Every Rumtoo Dissolved Air Flotation system includes a comprehensive 12-month mechanical warranty.
12-Month Limited Warranty
Covers all core structural, pump, and electrical control components with fast spare parts dispatch.
Process Engineering Support
Our environmental process engineers provide full assistance for chemical jar testing, hydraulic sizing, electrical wiring, and startup commissioning.
Frequently Asked Questions
Clear answers about Dissolved Air Flotation, microbubble separation, chemical dosing, and water reuse rates.
Ready to Clean Your Process Water with DAF?
Contact our wastewater engineers today for technical guidance, sizing calculations, chemical dosage recommendations, and an itemized turnkey quotation.
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