Disinfection Ballast water

Disinfecting ballast water

Ballast water is being used for the stability of the ship. Large ships can uses millions of gallons of ballast water. The ballast water is pumped in to the ship at the harbour which it's in and deposited in the next habour it goes to.

The problem when this ballast water is pumped into the ship it also loads many of the organisms living in that port. These organisms vary from microbes to whole schools of fish. Some of these so called 'exotic' organismes that survive the trip, can do damage in the next harbour (port). Problems are disturbance of the biodiversity (eco system) which can cause for example low fishing rates and it can bring diseases like cholera which is dangerous for humans.

Up to 3000 different species are transported this way a day!

A solution is to load and dispose at sea, but many countries don't support this idea.
Another solution is to disinfectate the water. Methods of water desinfection are UV-systems, chlorine dioxide or ozone.

Criteria for Selecting a Treatment Method

  • Safety
  • Efficiency
  • Interference to normal ship operations
  • Structural integrity of the ship
  • Size of the instruments
  • Potential damage
  • Ease for port authorities to monitor for compliance with regulations

    The three disinfection methodes given above are suitable and apply according to all norms and criteria.