SECONDARY CIRCULAR CLARIFIER BRIDGE is a unit that facilitates the collection and removal of secondary sludge and scum from the mixed liquor. Influent is introduced into the center of the clarifier and flows through the central baffle towards the clarifier bottom. Solids are allowed to settle due to the low rising speed to the clarifier surface. Settled sludge is conveyed to the bottom center of the clarifier by the action of the scraper arms that are attached on to the rotating bridge. Surface scum is also collected with the use of a surface scraper that is attached into the rotating bridge and collected into a scum box.

Both secondary sludge and scum are conveyed to the sludge treatment facilities. Purified effluent overflows through a peripheral weir to the successive treatment stage.