english Dissolved Air Flotation (DAF) Process
Dissolved air flotation (DAF) is a highly effective water clarification process that separates suspended solids, oils, and other contaminants from water. Here's how it works.
1. Saturation Stage
In the saturation stage, a portion of the clarified water from the DAF system is pumped under high pressure (usually 3-7 atmospheres) into a pressure vessel where it comes into contact with compressed air.
- The high-pressure environment forces the air to dissolve into the water
- Creates a supersaturated solution of air-laden water
2. Flotation Stage
The supersaturated air-laden water is mixed with the raw water containing suspended solids.
- When pressure is released, dissolved air forms tiny bubbles (10-100 μm)
- Bubbles attach to suspended particles, oil droplets, and flocs
- Buoyancy causes contaminants to rise, forming a "scum" layer
3. Removal Stage
A skimming mechanism removes the floating contaminants from the water surface.
- Slowly moving scraper continuously removes the scum layer
- Clarified water is collected from the bottom of the tank
- Water can be further treated or discharged
This entire process effectively clarifies water by leveraging the buoyancy of air bubbles to separate and remove impurities, making DAF an efficient solution for water treatment applications.
