Dissolved air flotation is most effective for the removal of which substance?

Dissolved air flotation (DAF) is particularly efficient for the removal of algae due to its ability to separate particles based on their buoyancy. In the DAF process, air is dissolved in water under pressure and then released at atmospheric pressure, forming small bubbles. These bubbles adhere to the algae cells, causing them to float to the surface, where they can be skimmed off.

Algae, which often exist in water supplies or treatment systems, form clusters that can be effectively captured and removed with this technique. The rising bubbles facilitate the flotation of these light particles, making DAF a superior method for algae removal compared to other treatment processes.

In contrast, while suspended solids can also be removed by flotation technologies, the efficiency of DAF is particularly highlighted when dealing with softer, less dense material like algae. Although DAF can remove some microorganisms and metals, the mechanism of buoyancy and the small bubble interaction is more directly applicable and effective for algae, leading to its designation as the most effective target for this method.