An oil water separator is a device used to treat wastewater. It removes oils, grease and hydrocarbons, leaving only the non-hazardous water. The wastewater can then be disposed of safely in drainage. There are different kinds of oil water separators, and each one has a different capability. They are used for varying commercial and industrial applications. They also treat contaminants found in water, including free-floating oil, emulsified oil, dissolved oil, and suspended solids.