Application of flotation as a pretreatment process during desalination

The need for fresh sources of drinking water is becoming more and more urgent worldwide, including certainly many areas and/or countries across the Mediterranean sea. Reverse osmosis membranes, on the other hand, are known to be very sensitive to foulants as colloids, inorganic scale and biofouling; so, pretreatment of their seawater feed is often a key step. In desalination plants design, various techniques have been proposed for pretreatment, even other membranes such as ultrafiltration. Nevertheless, may be among the more conventional belongs nowadays flotation (usually, in its dissolved-air option for bubbles generation), followed by filtration and preceded by screening. Flotation constitutes a high rate, effective and familiar separation process for oil, grease and suspended solids, like the algae. In potable water treatment, the process chain of flocculation–flotation–filtration is rather a common concept. The present paper will be a review of this interesting area with focus on sustainable development.