Hi Oksana, We have some ...

Hi Oksana,

We have some good experience in bilge water treatment we use free oil separation (decantation or tangential separator like the hydrocyclone mentioned it depend on the oil content, then we can look at very compact Ultrafiltrtion membrane for dissolved low molecular weight organic they can go to biologic treatment plant as mentioned in another answer.  We use BDD Boron Dope Diamond electrode to reduce/destroy COD and provide total disinfection allowing to discharge bilge water back at see.

In general terms you oil/water separation will be: -
-mechanical oil and water don't mix so a large part of the oil will coalesce and be removed mechanically.
-if you have emulsified oil in the water you will need to further treat either by changing the chemistry or by Filtration that can be UF/NF typically
- Dissolve organic will be removed by oxidation being Biologically , chemically or electrochemically.

On board ships, size matters and compact system can be advantageous sanitation of the effluent is also essential nowadays. So UF/BDD is a good solution and different configurations exist. our BDD also allows to produce Oxidant/disinfection on demand and in-situ so no need for any chemical store chemical dosing or manhandling 

If you need to know more or you are looking for specific please contact me.