Keeping ballast water clean

28 September 2006

Hitachi Plant Technologies has developed a system to purify ship ballast water that is considered to cause marine pollution due to its high plankton and bacteria content.

The system combines the agglomeration techniques used in water treatment plants with the company's commercial superconducting electromagnetic separation technology to purify blue-green algae and other phytoplankton. Agglomeration is the adherence of particles into a small mass due to moisture, static charge or chemical or mechanical binding.

As the system does not use chlorine or ultraviolet rays, the purified water does not cause cross-contamination. The efficiency of the system is achieved by the agglomeration technique, which speeds up the flow of water.

The system will be tested until the end of December in Tokyo Bay, and presented at the 3rd International Conference & Exhibition on Ballast Water Management at Singapore on 25 September.