sedimentation

Particles such as viruses, colloids, bacteria, and small fragments of silica and alumina may be separated into different fractions of various sizes and densities. Suspensions of relatively massive particles settle under the influence of gravity, and the different rates can be exploited to effect…

…have shed much light on sedimentation in the Gulf of Mexico, the Black Sea, and the Baltic Sea, and in various estuaries, lakes, and fluvial basins in all parts of the world.

Impurities in water are either dissolved or suspended. The suspended material reduces clarity, and the easiest way to remove it is to rely on gravity. Under quiescent (still) conditions, suspended particles that are denser than water gradually settle to the bottom of a basin…