Flotation is an effective process to remove relatively light types of particles e.g. organic material and algae. This process involves the formation of small air bubbles that are passed through flocculated water, which had been treated with chemicals. The bubbles attach to the light-weighted flocs causing them to rise to the surface where they are collected as froth and removed from the top of the flotation unit. Heavier particles will settle as sludge and is normally decanted once a day. The froth and sludge are treated in a separate process where the water is reclaimed and the concentrated sludge discharged to drying lagoons. DAF is an effective process which produces effluent with reduced suspended solids and reduced amounts of algae.
Design specifications of the DAF Plant
| Design | Modular, 5 x 50 Ml / day |
| 250 Ml / day | 250 Ml / day |
| Retention time | ± 1 hour |
| Recycle stream | 7 – 10% v/v |
| Bubble size | 0,5 mm |
| Pressure vessels | 500 kpa |
| Sludge concentration | 1.5 – 2% |
| Flocculation | Serpentine channels; adjustable outlets |
| Air : water | 1:1 |
