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Encyclopedia of Marine and Energy Technology

Ballast Water Treatment Systems (BWTS)


Ballast Water Treatment System (BWTS) is a system designed to remove and destroy/inactive biological organisms (zooplankton, algae, bacteria) from ballast water. Ballast water treatment is still evolving technology with an ever-growing number of manufacturers. This means that there is limited inservice experience for the systems being offered and there is a general understanding that no single system is suitable for all ship types. See also AQUARIUS ballast water treatment plants.

Most Ballast Water Treatment Systems use a two-stage approach, involving a form of mechanical separation (1st stage) followed by physical or chemical treatment (2nd stage). The two most common technologies are Ultra-Violet (UV) based systems and Electro-Chlorination (EC) systems. UV systems use physical UV radiation as secondary treatment, where electro-chlorination makes use of a chemical ‘active substance’ to inactivate biological organisms. Both systems typically employ filtration as mechanical first phase treatment.

UV based BWTS (more on UV treatment)

Ballast water - Aquarius UV


Electro-Chlorination BWTS (more on EC treatment)

Ballast water - Aquarius EC