Foaming in this case is caused by the surfactants and is usually stable and light in color. Anti-foams tend to work well on surfactant foams.
Corrective Actions
- Discover source of both oils and surfactants - with the goal of keeping problems out of the wastewater treatment plant
- Use anti-foams to control foaming
- Be prepared to increase wasting as oils (grease) will get bound into the floc
- If you notice a loss of biological activity (OUR, Microscopic exam, effluent turbidity) - this is a case where bioaugmentation is very effective in keeping the system healthy and degrading the offending surfactants/grease
And remember that removing grease in the WWTP is important because:
- It can favor growth of Nocardia forms with foaming
- Makes dewatering sludge difficult
- Solids settling rates can decrease and floating MLSS in the clarifiers