4 Remedial and Corrective Actions
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - Circulars - Marine Environment Protection Committee - MEPC.1/Circular.677 – Guide to Diagnosing Contaminants in Oily Bilge Water to Maintain, Operate and Troubleshoot Bilge Water Treatment Systems – (22 July 2009) - Annex – A Guide to Diagnosing Contaminants in Oily Bilge Water to Maintain, Operate and Troubleshoot Bilge Water Treatment Systems - Annex 3 – Emulsions - 4 Remedial and Corrective Actions

4 Remedial and Corrective Actions

 ▸ Flush OWS with hot water (sometimes this can enhance performance). Pump the washwater into bilge and try circulating again. If this brings the OCM reading down, repeat.

▸ Heat the bilge water prior to entering the OWS. Heat will cause droplets (emulsion) to coalesce and come out of solution.

▸ Engage polishing technology.

▸ For particulates that create emulsions only: employ (by and large for newer ships or major upgrades only) high-aspect ratio (height to width) separation tanks in conjunction with heat and serial decanting. See annex 4 and note below.

▸ Store (segregate and then clean the bilge) or pump the emulsified bilge water to a shoreside reception facility.

▸ While recognizing that small solids can create an “emulsion” it may be best to treat the solids removal separately, see annex 4.

Note: These techniques reduce the overall loading seen by the treatment system. Removal of solids that create emulsions using these kinds of methods will reduce the amount of material being sheared in the treatment system. Particulate matter can contribute to emulsification of oils and can present problems on its own. In the broadest sense, this recommendation probably belongs in the particulate filtration area, with reference made to the tendency of some particulate matter to enhance emulsification of oils. Additionally, these emulsions are pseudo-stable and over time some significant portion does tend to coalesce out in tank. This is an important point to consider in regard to future design of ships in order to minimize the burden on the treatment system and to make the whole system more user-friendly and observable.

Parent topic: Annex 3 – Emulsions
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