ABSTRACT
Solids that are lighter than water (oil, grease, and other žoating materials) žoat to the top, forming scum. These žoating solids are skimmed from the surface and removed. Wastewater žow leaves the sedimentation tank over an efžuent weir for further treatment. Process ef›ciency is controlled by detention time (normally about 2 h), temperature, tank design, and equipment condition.
