Dear Oksana, We have plenty ...
Published by Bruno Peeters, managing director at Model Engineering
Dear Oksana,
We have plenty of expertise in treating wastewater from the petroleum industry.
After buffer storage with equalisation, the first treatment step shall indeed be oil-water separation with oil recovery as replied by others. If the level of free oil is high than a simple gravity separator will remove 80%-90% of the oil. Hydrocyclones can also be used but their design and operation is tricky and they require relative high pressure pumps.
Further oil removal including emusified oil (up to 99% removal) is achieved by Dissolved Air Floatation (DAF).
Finally the soluble organics are completely removed by advanced activated sludge (AAS) biological treatment resulting in clean water for reuse.