New IMO test simulates bilge water treatment under ?real life? conditions

With effect from January 1, 2005, bilge water treatment systems installed in newbuildings and retrofitted on existing ships must fulfil tougher demands to gain IMO approval. While the limit for the oil content in bilge water pumped overboard remains the same at 15 ppm, an additional step is being added to the IMO test procedure. The extra step, involving emulsions, is designed to ensure that bilge water treatment systems perform efficiently under “real life” operating conditions.

Today?s IMO tests involve cleaning two batches of water contaminated with heavy fuel oil, HFO, and diesel oil, DO, respectively. However, bilge water rarely contains only water and oil. It is typically a complex chemical cocktail of water contaminated by oils, chemicals, detergents, additives, and particles in varying composition, often in more or less stable emulsions. The additional IMO test uses a mixture of an oil-in-fresh water emulsion to simulate actual bilge water and the mixture contains HFO, DO, surfactants and iron oxide which pose a challenge for less efficient, conventional static bilge water separator systems that gained IMO approval under the previous rules.

There is a much greater issue here than an IMO rule for cleaning bilge water. It?s about taking responsibility for the environment. The new IMO approval will leave suppliers of bilge water treatment systems with no choice but to lay their cards on the table. All systems should be designed to meet real-life working conditions.