Ballast water treatment systems (BWTS) are designed to remove and inactivate biological organisms (zooplankton, algae, bacteria) from ballast water. BWTS technology is still evolving, with a growing number of manufacturers. This means that there is limited experience with the performance of these systems in service, and there is no single system that is suitable for all ship types.
Most BWTSs use a two-stage approach, with a mechanical separation process (first stage) followed by physical or chemical treatment (second stage). The two most common technologies are ultraviolet (UV)-based systems and electro-chlorination (EC) systems. UV systems use physical UV radiation to inactivate biological organisms, while EC systems use a chemical “active substance” to achieve the same result. Both systems typically use filtration as a mechanical first-phase treatment..
