Biofouling within the cooling water systems of ships can be serious enough to cause immobilization. Marine growth on pipes also promotes crevice corrosion. In seawater, blue mussels are the predominate species that cause biofouling. A biofouling test system was constructed at the Dockyard Laboratory in Halifax, Nova Scotia by the Defense Research Establishment Atlantic. Seawater from the Halifax harbor continuously flowed through pipe networks that were designed to
simulate the cooling water piping on a ship. Three commercial chemical injection systems were tested simultaneously, namely copper, iodine and hypochlorite. Personnel from the Bedford Institute of Oceanography assessed the biological effectiveness of each system by observing adult mussels one at a time in a beaker of treated water. These tests revealed a wide range of effectiveness between these chemicals in preventing mussel attachment. Each injection system was better than no treatment at all. As designed and operated, the copper and iodine release systems were only modestly effective whereas the hypochlorite system was completely effective in preventing mussel attachment. Observations of the
piping after several months of flow-through operation were consistent with the biological tests with treated water. The process engineering for installing a hypochlorite system on a ship is described.
Keywords: anti biofouling agents, mussels, copper, iodine, hypochlorite