8. Aerated lagooning

8.1 Oxygenation: principle

• General description

  In aerated lagoons (figures 20 and 21 ), oxygenation is provided. Oxygenation in aerated lagoons is achieved by means of a surface aerator, which uses blades to stir the water and promote oxygen exchange between water and air. Air insufflation can also be used, where air is injected into the water to increase the level of dissolved oxygen.

  Unlike activated sludge, this method is distinguished by the absence of a system for continuous sludge recycling or extraction....