english Combination Air Flotation (CAF) is an advanced water treatment technology that integrates dissolved air flotation (DAF) and induced air flotation (IAF) to achieve superior contaminant removal. Its treatment effectiveness depends on several key factors:
1. Contaminant Removal Performance
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Oil & Grease Removal: Achieves 90-99% removal efficiency for free oils and emulsified hydrocarbons.
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Suspended Solids (TSS): Removes 80-95% of fine particles (10-100 μm) through microbubble adhesion.
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COD Reduction: Typically reduces COD by 40-70% when combined with coagulants (e.g., PAC, polymers).
2. Key Advantages Over Conventional Systems
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Microbubble Technology: 20-50 μm bubbles provide larger surface area for contaminant adhesion.
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Hybrid Design: Combines pressurized DAF (for fine bubbles) and mechanical IAF (for high-load shocks).
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Compact Footprint: 30-50% smaller than traditional clarifiers.
3. Influencing Factors
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Chemical Optimization: Coagulant dosage (e.g., 50-200 mg/L PAC) significantly impacts floc formation.
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Hydraulic Loading Rate: Optimal at 3-10 m³/m²/h; exceeding this reduces efficiency.
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pH Range: Works best at pH 6-8; extreme pH requires adjustment.
4. Industrial Applications
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Food Processing: Removes fats/oils from slaughterhouse wastewater.
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Petrochemical: Treats API separator effluent with <10 ppm residual oil.
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Pulp & Paper: Reduces fiber losses in whitewater recycling.
5. Limitations
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High Energy Use: Requires 0.5-2 kWh/m³ for air dissolution and recirculation.
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Temperature Sensitivity: Cold weather (<5°C) may reduce bubble stability.
