Press release 2016-06-13

Oily bilge water can be purified to drinking water quality

Today marine shipping has the right to discharge a limited amount of oil at sea, along with bilge water from the engine compartment. The Bonus project ZEB (Zero Emissions in the Baltic Sea) has developed technology that purifies bilge water to near-zero levels of contaminants.

Every year a few dozen tonnes of oil end up in the Baltic Sea via discharges of contaminated bilge water from marine vessels. Many ships have modern wastewater treatment systems on board that remove a large proportion of oil residues, but the bilge water may still contain oil concentrations of up to 15 ppm.

– The amount of oil may not be the most alarming factor, but bilge water contains many other impurities that are also toxic to the marine environment. And the Baltic is known to be a sensitive sea, says Hulda Winnes project leader at IVL.

Together with the Finnish corporation Wärtsilä and the Klaipeda University in Lithuania, IVL Swedish Environmental Research Institute has augmented existing treatment technology to the point where oily bilge water can be purified to drinking water quality.

– We have shown that it is possible to get far with quite simple supplementary technology, says Hulda Winnes.

In addition to technology development, the project will identify hotspots in the Baltic, where the environment is particularly sensitive and emissions are high. The new technology will also be compared with existing purification techniques in a full life cycle analysis.

BONUS ZEB is presented at the European Maritime Day in Turku, Finland, 18 May, and during Almedalen week in Visby Gotland, July 3.

For more information please contact:
Hulda Winnes, hulda.winnes@ivl.se, +46 (0)10-788 67 60