Dissolved Air Flotation

Dissolved Air Flotation (DAF) system is a superior counter current system designed to achieve maximum treatment efficiency in a compact footprint. It is able to remove a variety of contaminants to meet trade waste or reuse requirements. Each system is sized based on the hydraulic loading rate, Total Suspended Solids (TSS) and Fats, Oil and Greases (FOG) levels. The surface loading rate that can be applied is dependent on each application.

dafsystem process

The DAF separates the suspended solids and lighter liquid contaminants (eg FOG and hydrocarbons) from the water by moving them to the surface of the DAF vessel and then scraping them off the surface. A pressurised stream of airsaturated water is mixed with the flocculated water and with the release of pressure, a cloud of very fine air bubbles carries the suspended solids and lighter liquids to the tank surface. Clean water overflows from the DAF tank, via an under/over-weir to sewer or to the next stage of the treatment process. The overflow level is adjustable and controls the level in the DAF flotation section. The sludge on the surface of the DAF is scraped into a sludge hopper by a mechanical scraper. The DAF system is automated via a programmable logic controller (PLC) mounted within a control cabinet on the system.