Method and device for treating ballast water onboard ships

摘要

Treating ballast water, comprises adding equilibrium peracetic acid and catalase to the ballast water on uptake of ballast water into a ship, where equilibrium peracetic acid is added in an amount of 5-50 mg/l peracetic acid and catalase is added in an amount which decomposes the content of the hydrogen peroxide introduced with the equilibrium peracetic acid to less than 2 mg/l in the ballast water within 120 hours. An independent claim is also included for a device for treating the ballast water comprising a ballast water tank (1), a conduit (2) for filling the ballast water tank and a line (8) for emptying the ballast water tank, where metering devices for equilibrium peracetic acid and catalase are connected to the conduit for filling the ballast water tank, and a metering device (17) for a reducing agent is connected to the conduit for emptying the ballast water tank.