A study of the effectiveness of antifouling electrodes in the marine environment

Abstract

Antifouling systems based upon Cu/Al and Cu/Fe electrodes were tested both in enclosed pipes and chambers (simulating cooling systems), and upon panels and metal structures exposed to the full influence of tides and wave action. Fouling organisms failed to settle/grow in treated enclosed systems, while electrode-protected glass fibre panels/steel structures mounted intertidally in the Menai Strait remained almost devoid of biological fouling during the summer months when control installations became heavily fouled. Laboratory tests established that the antifouling action of electrodes was due to the dissolution of copper (in the ppb range), and not to the formation of a colloidal copper complex between copper and aluminium hydroxide. The unexpected effectiveness in non enclosed situations is believed to be due to high local copper concentrations maintained near the electrodes during slack water periods, and suggests a novel function for such electrodes—the localized protection of structures or instruments which cannot be treated with antifouling paints.