What is sedimentation in the context of water treatment?

Sedimentation refers specifically to the process where solid particles in water settle out due to gravity. In the context of water treatment, this step is crucial as it allows for the removal of suspended solids, which can include dirt, silt, and other particulates. By allowing these materials to settle, water treatment facilities can achieve clearer water, which is essential for effective filtration and disinfection processes that follow. This natural process is an economical and efficient way to improve water quality before further treatment steps are employed.

This process is typically facilitated in a sedimentation basin or clarifier, where water is held for a period, allowing the heavier particles to settle to the bottom, forming a layer of sludge. The clarified water above the settled solids can then be collected and treated further.

The other choices do not accurately describe sedimentation; they address different methods involved in water treatment but do not relate directly to the settling process of solids.