What occurs during the sedimentation process in water treatment?

During the sedimentation process in water treatment, suspended particles settle out from the water due to the force of gravity. This process is fundamental in the removal of solids from water, allowing for clearer water to be produced for further treatment or use. As water sits in a sedimentation tank, the heavier particles gradually fall to the bottom, forming a layer of sludge. This action helps in reducing turbidity and preparing the water for subsequent purification stages.

Suspended particles that do not settle out remain in the water, which is why the correct answer emphasizes the settling aspect of sedimentation. The other options reflect misconceptions about the process; for instance, sedimentation does not remove all contaminants completely, and water becomes less turbid, not more, as the solids are removed during this phase.