Oil-water separators are one of the key components in the wastewater treatment process. The wastewater, after filtering the largest solids, is funneled into the oil-water separator. Here, the wastewater travels across a series of plates installed with an inclination inside the separator. These plates aid to separate oil, water, and sludge into three distinct spaces. The main working philosophy is the density difference. The heavy sludge and suspended solids being heavier drop to the bottom. On the other hand, oil particulates are lighter and rise to the top.

However, the plates perform a special function. When the wastewater passes over the plates, small oil particulates are tumbled over the surface. This step helps to collect the oil particles and form larger globules, increasing buoyancy. This increased buoyancy further helps more of the oil to separate and rise to the top of the water.

The stacked plates increase the surface area over which wastewater must pass. At the same time, the inclination of the plates helps to force the oil up to surfaces to coalesce and form larger particles.