After the adoption of the International convention for control and management of ship’s ballast water and sediment on 13th Feb 2004 by IMO, different ballast water treatment methods have been introduced. One such method is the installation of Ozone generator system onboard ship with ballast system.
What is Ozone?
Ozone is a colorless oxidizing biocide with a pungent smell and is formed naturally in earth’s atmosphere. It has very unstable properties and when injected in water decomposes rapidly. It has been found that ozone is one of the most powerful and fastest oxidizer which oxidizes bacteria present in water like molds, yeasts, organic material and viruses etc.
Ozone generator is a machine that generates ozone gas by using oxygen from the atmosphere. The principle of the generator is as follows;
Energy from an electric discharge field is used along with ambient air which flows through the ozone cells responsible for converting and increasing the amount of ozone gas. The ozone gas is then injected in to the ballast water by an injector unit.
This ozone gas dissolves, decomposes and reacts with other chemical and kills organisms present in water and thus makes ballast safer to discharge in any ocean water.
General Lay out of the system
The basic lay out of the system comprises of an ozone generator, injector unit, line filter, and neutralizer.
Line filter is fitted before the ozone generator and the injector unit, whereas the neutralizer is fitted on the discharge line of the ballast system. The neutralizer comes in use when the water is de-ballasted from the ship.
Neutralization is done because ozone is a toxic gas and can harm humans. The gases that are not dissolved thus need to be removed by neutralizer before discharging back to sea
The Ozone generator system is more effective for removal of larger organisms when combined with other treatment methods like electrolysis or UV methods.
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