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Dairy Fat & Protein Recovery

Milk fats and proteins in dairy wastewater represent valuable resources that can be recovered and repurposed. Our DAF flotation systems effectively separate and concentrate these materials for animal feed, protein concentrate production, or energy recovery through anaerobic digestion.

Milk Fat Separation

DAF flotation achieves 95%+ removal of milk fats and oils from dairy wastewater. Micro-bubbles attach to fat droplets, floating them to the surface for skimming. The concentrated fat layer can be processed for animal feed or biodiesel production, creating value from waste.

95%+ Fat RemovalFeed Recovery

Whey Protein Recovery

Whey proteins can be concentrated through ultrafiltration before wastewater treatment, creating valuable WPC (Whey Protein Concentrate) products. Remaining permeate requires advanced biological treatment but with significantly reduced organic load and treatment costs.

WPC ProductionCost Offset

Casein Recovery

Casein residues from cheese production and equipment washdown can be recovered through coagulation and separation processes. Recovered casein can be repurposed for industrial applications or further processed, reducing waste disposal requirements and costs.

CoagulationWaste Reduction

Biogas Production

High-strength dairy wastewater with fats and proteins is ideal for anaerobic digestion. Biogas production provides renewable energy for plant operations while achieving 80-90% COD removal. Energy recovery can offset 30-50% of treatment operating overheads.

Energy Recovery80-90% COD Removal

DAF Technology for Dairy

Our DAF systems with optimised polymer chemistry achieve exceptional removal of milk fats and proteins. The concentrated float can be processed for animal feed, protein concentrate, or directed to anaerobic digestion for energy recovery.

Micro-Bubble Flotation

Saturator systems generate 20-50 micron air bubbles that attach to fat and protein particles, achieving rapid flotation. Bubble size optimisation ensures efficient separation even with emulsified dairy fats that resist gravity separation.

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Polymer Optimisation

Specialised cationic polymers enhance coagulation of negatively charged dairy proteins and fats. Our polymer dosing systems automatically adjust to varying wastewater loads, ensuring consistent performance during production cycles.

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Float Concentration

DAF systems concentrate fats and proteins to 4-8% solids content, significantly reducing volumes for disposal or further processing. Concentrated float is ideal for screw press dewatering or direct animal feed applications.

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Performance Monitoring

Integrated monitoring systems track inlet and outlet fat/protein levels, chemical dosing rates, and float thickness. Real-time data enables optimisation and ensures consistent compliance with discharge requirements.

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Whey Protein Considerations

Cheese production whey contains valuable proteins that can be concentrated through ultrafiltration before wastewater treatment. This creates additional value streams while significantly reducing treatment load and operating overheads.

Ultrafiltration (UF)

UF membranes concentrate whey proteins to 35-80% protein content (WPC 35-80), creating valuable products for sports nutrition and food ingredients. Permeate with reduced protein content requires less intensive advanced biological treatment.

Output: -500/tonne WPC

Whey Protein Isolate (WPI)

Further processing through microfiltration and ion exchange produces WPI with 90%+ protein content. Premium product commands higher rates but requires more sophisticated processing equipment and quality control.

Output: -1500/tonne WPI

Lactose Recovery

Crystallisation of permeate lactose creates food-grade lactose for pharmaceutical and infant formula applications. Further reduces organic load and generates additional output from what would otherwise be waste.

Output: -600/tonne Lactose

Permeate Treatment

After protein/lactose recovery, permeate still contains dissolved organics requiring treatment. Anaerobic digestion is ideal for permeate, producing biogas while achieving high COD removal with minimal energy input.

COD Reduction: 80-90%

Treatment Performance

ParameterTypical InletAfter DAFAfter BiologicalRemoval Rate
Fats & Oils200-1000 mg/L< 15 mg/L< 5 mg/L98-99%
BOD2000-5000 mg/L1500-3500 mg/L< 100 mg/L95-98%
COD4000-10000 mg/L3000-7000 mg/L< 200 mg/L95-98%
TSS500-2000 mg/L< 100 mg/L< 30 mg/L95-98%
pH4.5-9.06.5-8.56.5-8.5Neutralised

Recommended Equipment

DAF Flotation Units

High-efficiency fat and protein separation with optimised polymer dosing and automated float removal. Stainless steel construction for dairy environments.

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Polyelectrolyte Stations

Automated polymer preparation and dosing systems for optimal coagulation and flocculation. Ensures consistent DAF performance with minimal chemical consumption.

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Screw Presses

Dewater DAF float to 18-22% dry solids for reduced disposal requirements or animal feed production. Low-energy operation with minimal maintenance.

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Anaerobic Reactors

UASB and EGSB reactors for high-strength dairy wastewater. Biogas production provides renewable energy while achieving 80-90% COD removal.

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Fat & Protein in Dairy Wastewater

Milk Fat Characteristics

Density0.93-0.94 g/cm³
Melting Point32-36°C
Particle Size0.1-20 μm
BOD Contribution~2.9 g O2/g fat
Key Challenge: Milk fat solidifies below 35°C, causing pipe blockages and separator inefficiency.

Protein Characteristics

TypesCasein (80%), Whey (20%)
Molecular Weight14-375 kDa
Isoelectric PointpH 4.6 (casein)
BOD Contribution~1.0 g O2/g protein
Recovery Value: Whey protein concentrate can be -5,000/tonne.

Typical Fat & Protein Content by Dairy Product

Product TypeFat (%)Protein (%)Wastewater FOG (mg/L)Wastewater Protein (mg/L)
Whole Milk Processing3.5-4.03.2-3.5200-500300-800
Cheese Production20-3520-30500-2,0001,000-5,000
Butter Production80-820.5-1.02,000-10,000100-300
Whey Processing0.2-0.50.8-1.050-200800-1,200
Ice Cream Production10-163-5300-1,000400-1,000

Fat & Protein Recovery Metrics

95%+
Fat Removal Rate
4-8%
Float Solids Content
-500
WPC Output/tonne
80-90%
Permeate COD Reduction
-500k
Annual Whey Output

Fat & Protein Recovery Technologies

DAF Flotation

Primary separation of fats and proteins

  • 80-95% fat removal
  • 60-80% protein removal
  • Concentrated float sludge (3-8%)
  • Chemical dosing: 50-200 mg/L

Membrane Filtration

UF/MF for protein concentration

  • 95-99% protein retention
  • Whey protein concentrate (WPC)
  • Permeate for reuse/discharge
  • Flux: 50-150 LMH

Centrifugal Separation

High-speed fat separation

  • 90-98% fat separation
  • Continuous operation
  • Concentrated cream (40-70% fat)
  • High throughput

Recovered Product Applications

Animal Feed

Recovered fat and protein can be used in animal feed formulations, providing high-energy nutrition for livestock.

Value: -600/tonne

Cosmetics

Milk fat derivatives are used in soaps, lotions, and cosmetic products for their moisturizing properties.

Value: -5,000/tonne

Sports Nutrition

Whey protein concentrate and isolate are premium ingredients for protein powders and sports supplements.

Value: -15,000/tonne

Biogas Production

Residual organic matter can be anaerobically digested to produce biogas for energy generation.

Value: -0.10/kWh

Related Pages

Confectionery

Wastewater treatment for confectionery and candy production.

View Page

Dairy Butter

Butter plant wastewater treatment with milk fat recovery.

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Dairy Cheese

Specialised treatment for cheese making wastewater.

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Dairy Fluid Milk

Wastewater treatment for fluid milk processing plants.

View Page

Dairy Food

Specialised wastewater treatment for dairy & food processing.

View Page

Dairy High Bod

Treatment for high-BOD dairy effluent from cheese, whey and milk powder production.

View Page

Fat & Protein Chemistry in Dairy Effluent

The two components that drive every dairy DAF design decision.

Fat Globule Structure

Native milk fat globules 0.1–15 μm with phospholipid + protein membrane. Homogenisation reduces to 0.5–2 μm, increasing emulsion stability. Removal requires chemical destabilisation.

Casein Behaviour

Casein micelles (50–300 nm) stable at neutral pH via Ca-phosphate bridges. Below pH 4.6 (isoelectric point), micelles aggregate. Above pH 12, hydrolysis releases free amino acids.

Emulsion Breaking

Three options: pH shock to 4.6 (acid demulsification), high-charge cationic polymer (5–25 mg/L), or thermal stress (>70°C for 20 min). Combined treatment gives best DAF performance.

DAF Coagulant Doses

FeCl₃ 80–300 mg/L breaks fat-protein emulsion via charge neutralisation + sweep flocculation. Alum less effective for dairy. PACl alternative for low-alkalinity streams.

Whey Protein Recovery

Ultrafiltration at 10 kDa MWCO retains whey proteins (β-lactoglobulin, α-lactalbumin). Permeate (lactose + minerals) goes to biology; retentate sold as 35–80% protein concentrate.

Hardness & pH Interaction

Ca²⁺ bridges stabilise casein; CIP softening or sequestration with EDTA / citrate destabilises. pH adjustments require lime (Ca-bearing) or NaOH (sequestration-safe). See pH correction + comparative oil-gas pH.

Need help with fat & protein separation?

Our dairy wastewater experts can design a system tailored to your specific requirements, from DAF flotation to complete treatment processes with resource recovery.

Industries We Serve

Our expertise spans multiple industries with sector-specific water treatment solutions.