DAF of Organic Cheese Factory: From wastewater to clean water outlet

DAF in Dairy Wastewater Treatment: A Technical Approach

Dairies and cheese production facilities generate wastewater with a high organic load, increased content of fats, proteins, and suspended solids. The typical parameters that characterize this wastewater are:

• BOD5: 1,500 – 3,000 mg/L
• COD: 3,000 – 6,000 mg/L
• Total Suspended Solids (TSS): 500 – 1,500 mg/L
• Fats, Oils & Grease (FOG): 200 – 800 mg/L

The direct discharge of such wastewater is environmentally harmful and does not comply with legislative requirements. For this reason, modern wastewater treatment technologies are applied, with DAF (Dissolved Air Flotation) being one of the most efficient solutions at the pre-treatment stage.

How DAF Works

The DAF technology is based on the generation of microbubbles of air (20–80 μm), which attach to the wastewater particles (fats, proteins, suspended solids). The mixture floats to the surface and is removed by a mechanical scraper.

Basic steps:

1. Wastewater inlet – wastewater is directed to an equalization tank and then to the DAF unit.
2. Chemical dosing – addition of coagulants/polyelectrolytes to improve flocculation.
3. Air saturation – part of the effluent is recirculated under pressure with air, creating saturated water.
4. Bubble release – the saturated air is released into the tank, generating microbubbles that attach to the particles.
5. Flotation & sludge removal – the floated sludge is removed from the surface, while the clarified water exits from the bottom.

Treatment Efficiency

With proper design and operation, a DAF system for dairy wastewater can achieve:

• BOD5 reduction: 60 – 70%
• COD reduction: 50 – 65%
• TSS removal: 80 – 90%
• FOG removal: > 90%

This significantly reduces the organic load that reaches the biological stage (aeration tank), ensuring:

• Lower energy consumption
• Avoidance of biological system overloading
• Stable operation and long-term sustainability

Application in a Dairy – Video Presentation

In the video by Tycherós – Chatzis Co., the complete process is presented:

1. Wastewater inlet from the dairy
2. Treatment via DAF
3. Effluent of clean water meeting the required standards

The treated water can be safely discharged into a natural receptor or reused in processes where permitted.

Watch the full video here

The Contribution of Tycherós – Chatzis Co.

With many years of experience in wastewater treatment projects, Tycherós – Chatzis Co. designs and constructs systems tailored to the specific needs of each industry.

Our expertise in DAF systems, combined with integrated biological treatment solutions, ensures:

• Compliance with environmental regulations
• Optimized energy performance
• Reliability and low operating costs