Electrolytic Disinfection of Seawater

The Problem

Invasive marine species are one of the four greatest threats to the world’s oceans, the impact of which is generally irreversible. The diverse range of organisms that ship’s carry in their ballast water remains the biggest pollution challenge facing the shipping industry today since there are thousands of marine species small enough to pass through ships’ ballast water intake and pumps. These include bacteria and other microbes, small invertebrates and the eggs, cysts and larvae of various species.

The Approach

To address this problem, an Electrolytic Disinfection unit along with other treatments was proposed whereby a small portion of the ballast water is used as an electrolyte in a membrane cell in order to chemically ‘activate’ the water. When injected into the ballast water a mixture of oxidising disinfectants with a very short half life rapidly consumes the organic matter. Extensive long term experimental testing was carried out during this development to assess the rates of decay and production of unwanted by-products in order to meet strict regulations.

The Result

The Electrolytic Disinfection unit was developed and resulted in the client passing all stages of the Type Approval process whilst also being fully compliant with the International Maritime Organisation (IMO) Ballast Water performance standards and the International Convention for the Control & Management of Ships Ballast Water & Sediments.