Revista de ciencias e ingeniería de materiales

Corrosion Mechanism of Mild Steel in Acidic Solution and Adsorption Thermodynamics in the Presence of Water Hyacinth Extract

Abstract

Babatunde O, Ogunrinde SO, Aribike DS and Adeyemi AA

Inhibitory effect of water hyacinth extract on mild steel corrosion in acidified seawater was investigated by weight loss and gasometric techniques. Values of inhibition efficiency calculated from weight loss and gasometric techniques are in good agreement Inhibition efficiency was found to increase with increasing concentration of the extract. The effect of temperature, immersion time, and acid concentration on the corrosion behaviour of mild steel in the presence of extract were also studied. Temperature studies revealed an increase in activation energies and decrease in inhibition efficiency with rise in temperature. The adsorption of the inhibitor molecules on metal surface was in accordance with Langmuir adsorption isotherm. Kinetic treatment of the data obtained with or without plant extract indicates first-order electrochemical reactions. FT-IR analysis was carried out on the protective film formed on the surface of the metal to establish the formation of metal-ligand bond. The results obtained showed that water hyacinth extract could serve as an effective inhibitor of the corrosion of mild steel in acidified water.