A centrifugal water-oil separator, centrifugal oil-water separator] or centrifugal liquid-liquid separator is a device designed to separate oil and water by centrifugation

Centrifugation

Centrifugation is a process that involves the use of the centrifugal force for the sedimentation of mixtures with a centrifuge, used in industry and in laboratory settings. More-dense components of the mixture migrate away from the axis of the centrifuge, while less-dense components of the mixture...

. It generally contains a cylindrical container that rotates inside a larger stationary containter. The denser liquid, usually water, accumulates at the periphery of the rotating container and is collected from the side of the device, whereas the less dense liquid, usually oil, accumulates at the rotation axis and is collected from the centre.

Centrifugal oil-water separators are used for waste water processing and for cleanup of oil spill

Oil spill

An oil spill is the release of a liquid petroleum hydrocarbon into the environment, especially marine areas, due to human activity, and is a form of pollution. The term is mostly used to describe marine oil spills, where oil is released into the ocean or coastal waters...

s on sea or on lakes.