What is the purpose of sedimentation in water treatment?

The purpose of sedimentation in water treatment is to allow solid particles to settle out of the water. During the sedimentation process, water containing suspended solids is held in a basin or tank where these particles are allowed to gravity settle. As the flow of water slows, heavier particles settle to the bottom, forming a layer of sludge, while the clearer water remains above this layer.

This process is crucial because it helps reduce turbidity and improves the clarity of water before further treatment steps, such as filtration and disinfection, are undertaken. By efficiently removing up to 90% of suspended solids, sedimentation enhances the overall quality of the water, making subsequent treatment processes more effective.

Options regarding cooling water, removing dissolved gases, or aerating the water do not align with the primary function of sedimentation, which specifically focuses on the physical removal of solids from water.