Functions of Oil Water Separators Serve in Wastewater

Almost all developed countries have strict environmental laws that require the treatment of oily wastewater and stormwater runoff. Separators are a key element of this treatment. The right separator design improves operations while reducing costs, avoiding fines and potentially generating income by selling reclaimed oil. Various separators are available, including gravity separator tanks and coalescing plate separators.

Controlling Oil Spills

Although oil water separators North Carolina come in different shapes and sizes, their basic operating principle is similar. They usually apply extreme centrifugal force to separate wastewater and oil from each other. Wastewater enters a separator through the separator inlet. From there, it flows to the vertical tube coalescing pack, where gravity comes into play. Since oil is lighter than water, it forces oil droplets to the top of the separator while the water continues down through a baffle and a filter with a 100-micron pore size. An ideal model of this equipment is elevated above the ground. It makes cleaning it much easier and faster. This unit type is also more convenient when dealing with large industrial operations. It will also help you comply with environmental regulations without draining your entire wastewater into a tank. It will be easier to monitor the oil and water level in the tank and manage your waste accordingly.


Oil water separators remove dissolved hydrocarbons from industrial wastewater and stormwater runoff so they don’t enter municipal sewer systems or waterways. They are generally required as legal minimum pre-treatment systems for businesses that produce contaminated wastewater or oily stormwater runoff. The simplest design of an oil-water separator uses gravity to separate oil from wastewater. Because water and oil have different densities, the heavier water drops to the bottom, and the lighter oil rises to the top.

A more advanced type of oil-water separator uses a coalescing plate. Usually, the plates are made of a non-porous material like polypropylene and spaced about an inch apart. The plates attract small oil droplets that gather together and grow into larger droplets that float to the top of the wastewater. The larger droplets then skim off the water’s surface and are removed from the wastewater stream for further treatment. This process also removes the emulsified oils that would otherwise be drained with the wastewater into drains and sewer systems.

Controlling Erosion

Oil water separators are multi-chambered devices that separate the different components of wastewater into distinct spaces. This separation is based on oil and water having different densities, allowing heavier solids (sludge) to drop to the bottom while the lighter oil rises to the top. Oil is then skimmed off the top, and wastewater moves along for further treatment. The design of the separator ensures that flow is laminar in both directions. It prevents turbulence from disrupting the orderly rise of oil droplets. Stokes’ law is used to determine the rise velocity of the oil droplets based on their size and density.

Coalescing oil water separators take full advantage of gravity to remove oil from wastewater, enabling them to meet and exceed water authority discharge standards. These units are ideal for commercial kitchens, metalworking shops, service stations and other industrial settings where large quantities of oil are generated. They are also cost-effective and require low maintenance costs to operate.

Controlling Hazardous Chemicals

Oil water separators treat wastewater and make it safe to discharge into the drainage. They remove free-floating hydrocarbons like diesel, gasoline, vegetable oil, and suspended solids. It ensures that the pure water that goes back into the environment after treatment is clean and uncontaminated. In developed countries, local environmental laws strictly require separating oil and wastewater before releasing it into drainage. They rely on the principles of Stokes’ Law, which describes the velocity at which solid particles rise or fall in liquids based on their density. As a result, they are ideal for industrial use. These systems work efficiently for most wastewater, provided the water is relatively free of mineral oils and has a density similar to water’s.

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