Disecrete Paricles Settling (Type I Settling)

Sedimentation is a physical treatment process that utilizes gravity to separate suspended solids from water. The process is widely used as the first stage in surface water treatment to remove turbidity causing particles after coagulation and flooculation. Sedimentation is also (2 ) to increase sludge solids concentration in sludge thickening . Presedimentation is also used in some cases to remove settleable solids such as gravel, grit, and sand from river water before it pumped to the drinking water treatment plant.
In this lecture, the theory and design procedures for sedimentation basins are discussed. Examples design calculations for presedimentation , and also examples calculation for the determination of both Newton s law , and Stoke s law are presented through these calculations examples. The design of a sedimentation basin is dependent upon the concentration, size. and behavior of the solid suspension. In general, there are four types or classes of sedimentation. Type I sedimentation, known as discrete settling, describes the sedimentation of low concentrations of particles that settle as individual entities. Examples of type I settling in water treatment plants are the settling of silt from river water before coagulation, the settling of water softening precipitates, and settling of sand in filters after backwash.