Evaluation of various impressed current and sacrificial anodes for control of biofouling

Marine fouling occurs when certain marine organisms, ranging from simple plants to animals, attach themselves to underwater structures. In the offshore oil and gas industry, these organisms attach to the jacket structure of a platform and increase drag forces on the structural members. This can lead to fatal consequences. Cathodic protection used for corrosion protection locally enhances alkalinity around the steel structures. This increased alkalinity favours the attachment of organisms. The normal practice of overcoming problems resulting from biofouling is to frequently clean the surfaces. This practice is time consuming as well as costly. A study was carried out on various systems, without and with CP and the intensity of biofouling was examined. The studies were carried out on mild steel and the various systems, including mild steel without CP, with CP provided by aluminium anodes, with sacrificial hybrid system (aluminium + magnesium), sacrificial and impressed current hybrid system (aluminium + TSIA), cupronickel system and TSI ribbon anode. The TSI antifouling ribbon anode exhibited the best performance in terms of corrosion protection as well as antifouling characteristics. The details of the study are presented in this study.