PRIMARY CIRCULAR CLARIFIER BRIDGE is a unit that facilitates the collection and removal of primary sludge and scum from the influent. Raw wastewater 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 of the wastewater to the clarifier surface. Settled sludge is conveyed to the bottom center of the clarifier by the action of the scrapers that are attached on to the rotating bridge. Surface scum is also collected with the use of a surface scraper that is attached onto the rotating bridge and collected into a scum box. 

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