For many years the discharge of untreated ballast water in the port of destination has caused serious ecological and economic damage and sometimes also harm to public health. Organisms in ballast water find themselves in an alien environment, one where the absence of their natural enemies means they can multiply rapidly and threaten the ecological balance.

With the adoption of the Convention on Ballast Water Management, the International Maritime Organization (IMO) has reacted to the problem, which has been known of for some years. In future ballast water must be treated on-board to reduce the number of living organisms to a minimum. The convention applies from 2010, although there are transitional arrangements which depend on the keel laying date and the capacity of the ballast watertanks.

RWO has developed CleanBallast, a technology for onboard treatment of ballast water which reliably removes organisms, sediments and suspended solids in just two steps:

• a DiskFilter system for mechanical separation when taking in ballast water,

• followed by our advanced EctoSys® disinfection unit which further reduces the number of living organisms before reaching the ballast water tanks.

Advantages at a glance

⇒ Modular design
⇒ Can be implemented in new ships as well as to retrofits
⇒ Designed for realistic heavy duty operation / Extremely low energy consumption
⇒ High level of automation for operator convenience
⇒ Low system pressure loss
⇒ No increase in corrosion to the ballast system
⇒ Unique and efficient modular design DiskFilter system, self-cleaning without interruption of the flow
⇒ Flexible, highly efficient EctoSys® disinfection system
⇒ Fully automated
⇒ No danger for crew or ship and safe for the environment

The EctoSys® disinfection system is used again when de-ballasting in the destination port, since any remaining organisms can multiply and grow during the voyage. In this way a disruption-free and clean water cycle is ensured, from taking in to pumping out regardless of whether in river water, brackish water or seawater.


RWO's CleanBallast technology has been extensively tested in areas where tidal waters eject that sediments regularly occur in high concentrations of over 400 milligrams per litre. Even under those extreme conditions CleanBallast was able to exceed the IMO test requirements. Testing in this way allowed us to create the conditions for a rapid intake of ballast water and for short berthing times in harbour. The efficient removal of sediment also ensures that both the cost of tank cleaning and the loss of cargo capacity are substantially reduced.