Sludge Removal by Wastewater Treatment Clarifiers

As the video below points out, dirty wastewater enters from the center of the clarifier and very slowly makes its way towards the outside where the water spills over the weir. During that retention period, the solids have enough time to settle to the bottom, where they're later picked up as sludge, and the clarified, or cleaner water, spills out along the edge. Clarifiers are made in many different shapes and sizes all work on basically the same principle. The sludge is then processed to remove water, be neutralized biologically, and reduce the levels of pathogenic organisms.

Beneficial uses of treated municipal wastewater sludges on land include agriculture and silviculture uses; application to parks, golf courses, and public lands; use in reclaiming low quality or spoiled lands; and use as landfill cover or fill material. Disposal on land includes landfilling and permanent storage of dewatered sludge or sludge incinerator ash in lagoons or piles.