The existing technologies for treating wastewater containing oil and petroleum products usually involve a three-stage purification system:
- Capacitive settling tanks for oil separation;
- Pressure flotation units;
- Filters with stationary loading, where the filtering material is quartz sand, expanded clay, or foam polystyrene.
If oil-containing wastewater is discharged into the city sewer system or directly into a water body after purification, additional adsorbers with activated carbon or other effective sorbents are used.
The described technology for treating oil-containing wastewater can be used for treating wastewater containing oils and fats, which is relevant for food production or catering facilities.
The efficient design of settling tanks and filters allows for the design of two-stage purification systems for oil-containing wastewater in many cases, eliminating the flotation stage. Such a solution reduces the installation and operation costs.
If the discharged water has high quality requirements, additional purification by adsorption is provided at the final stage of oil and petroleum product treatment.