Which type of oils are generally NOT removed by oil water separators?

Soluble oils are the type of oils that are generally not removed by oil-water separators because they are typically emulsified or dissolved in water. Unlike floating oils, which can rise to the surface and be separated by the mechanical action of the separator, soluble oils remain mixed with water due to their chemical properties. This makes it challenging for them to be effectively separated using standard oil-water separation techniques, which rely on the ability of oils to float or coalesce.

In contrast, floating oils can accumulate on the surface, allowing for easier removal. Heavy oils may settle at the bottom of the separator but can also be removed depending on the specific design of the equipment. Mineral oils can exhibit behaviors similar to floating oils, making them more amenable to separation processes that are designed around physical properties. Therefore, understanding the nature of each type of oil helps in determining their compatibility with oil-water separation systems.