Removing Oil & Grease From Effluents | PRAB

Effectively Clean Oily Wastewater

Conventional approaches to treating oily wastewaters have included gravity separation and skimming, dissolved air flotation, de-emulsification, coagulation and flocculation. Gravity separation followed by skimming removes free oil from wastewater. This is done with an oil/water separator, which has been an effective, low cost, primary treatment step. Oil/Water separators are designed to separate the oil and suspended solids from their wastewater effluents. However, they are not effective in removing smaller oil droplets and emulsions.

Wastewater storage tanks in food production plant |

After pre-treatment, oil that adheres to the surface of solid particles can be effectively removed by sedimentation in a primary clarifier through a membrane process such as microfiltration, ultrafiltration, nanofiltration, or reverse osmosis.

Of the three broad categories of oily wastes-free-floating oil, unstable oil/water emulsions, and highly stable oil/water emulsions-membranes are most useful with stable emulsions, particularly water-soluble oily wastes.


PRAB offers a full-line of industrial water and wastewater solutions to help reduce haul-away costs, save on water use, and overcome regulatory challenges. To replace your existing system, or purchase a new system, contact us today.

Free White Paper

Overcoming the Operational Challenges of Wastewater Regulatory Compliance

White Paper: Overcoming the Operational Challenges of Wastewater Regulatory Compliance |