Sedimentation is a form of separating substances. This process involves letting an insoluble substance (a substance that will not dissolve in a solvent) settle at the bottle of a solvent. An example of this is if you mix chalk and water, the chalk will settle at the bottom of the glass after being mixed in because it does not dissolve in water. In most of the cases if done correctly water should purified on the top and the second component of the mixture should rest on the bottom.