Conventional Plug Flow

Recycled activated sludge and settled wastewater enter the head of the aeration tank and are mixed by diffused air or mechanical aeration.

Air application is generally uniform throughout the tank length. During the aeration period, flocculation, adsorption, and oxidation of organic matter occur. An activated-sludge solid are separated in a secondary settling tank. BOD removal efficiency varies between 85-95%.

                                      Figure 13: Conventional Plug Flow Activated Sludge Process