Corrosion inhibition of mild steel bars by biosurfactant produced by Penicillium citrinum

Abstract

Corrosion is a major challenge in the construction technology and manufacturing industries. Not only does corrosion reduce the aesthetics of a building, but it also reduces the durability of the structure. Various efforts and research are being carried out globally to overcome this problem, ranging from prevention to maintenance processes. Due to the increased awareness of the importance of preserving the environment for health and ecological systems, studies are increasingly focused on the use of environmentally friendly corrosion inhibitors. This study focuses on the effect of different concentrations of biosurfactant produced by Penicillium Citrinum on mild steel bar corrosion. The biosurfactant was produced from indigenous fungi isolated from the municipal dumpsite and uses waste frying oil (WFO) as the sole carbon source. Weight loss experiment (gravimetric) was carried out to analyse the corrosion inhibition rate and efficiency of the biosurfactant produced. The steel bars were conditioned by immersion in the 0.9% NaCl containing biosurfactant at different concentrations (v/v) of 5%, 7.5%, and 10% for 14 days, 28 days, and 100 days. The weight loss of the coated bars was compared to those of the control samples and the non-organic surfactant, Tween 80. The discovery demonstrates that corrosion inhibition increases as biosurfactant content increases. The results show that biosurfactants secreted by an indigenous soil fungus, Penicillium citrinum have the potential as green corrosion inhibitors in mild steel bars.