Industrial Oil/Water Separation

What is an Oil/Water Separator?

An oil/water separator is a device designed to separate oil and other hydrocarbons from water to treat industrial wastewater or augment a wastewater treatment process.  Separators are widely used in various industries, including oil and gas production, manufacturing, petrochemical manufacturing, wastewater treatment, and marine operations. The principle behind oil/water separators is based on the density difference between oil and water, which causes oil to float on the water's surface, allowing it to be removed more easily.  There are other factors that go into designing an effective oil/water separator system such as oil droplet size, size of the separator tank, flow rate, etc.

For some industrial waste streams, an oil/water separator may provide sufficient treatment on its own to reuse or discharge the treated water.  In many cases though, an oil/water separator is used as an important pre-treatment step upstream of a membrane system, evaporator, or other wastewater treatment technology.

1. Gravity Separators: These utilize the natural buoyancy of oil, which causes it to rise to the surface of the water where it can be skimmed off. They are simple in design and operation, making them suitable for a variety of applications.

2. Coalescing Plate Separators: These are designed with a series of plates that increase the effective surface area for oil droplets to coalesce (combine) and rise to the surface. This style system is more efficient than basic gravity separators and can remove smaller oil droplets.

3. Hydrocyclone Separators: These use a centrifugal force generated by a spinning motion to separate the oil and water. The centrifugal force pushes the higher density water outward to the hydrocyclone's wall, allowing the lower density oil to move towards the center for removal.

4. Other Technologies for Oil/Water Separation: Dissolved air flotation (DAF) systems and membrane systems such as Ultrafiltration are also commonly used for oil-water separation.