Chiedozie Valentine Oluigbo & Wahab Afolabi Ajibola

Organic inhibitors, such as plant extracts are now essential as a suitable source for a variety of corrosion inhibitors that are also affordable, readily obtainable and environmentally friendly. This study describes the inhibition effect of unripe Musa sapientum (banana) peel extract at varying pH values of HCl solution in the corrosion of mild steel. The experimental work was conducted under ambient conditions. A corrosion study kit using weight loss corrosion monitoring technique was employed for the investigation. This equipment has a voltage supply designed to accelerate corrosion rate. The corrosion inhibition investigations were conducted using experimental setups consisting of HCl solutions with pH values of 2, 3, 4, 5, and 6. 5mls of unripe Musa sapientum extract was maintained in each setup. Each experimental setup has its corresponding control. The findings corroborated the concept that corrosion rates increase with increasing acidity of the medium (lowering pH). It was concluded that the Musa sapientum peel extract performed better in weakly acidic media (pH6, pH5 and pH4) compared to strongly acidic media (pH2 and pH3), and hence can be used as organic ‘green’ corrosion inhibitor which can be used in place of expensive toxic chemical inhibitors. The inhibition was attributed to the physical adsorption of the inhibitor on the surface of the mild steel test specimens. Unripe Musa sapientum extract in pH6 medium after 2 hours exposure time exhibited the highest inhibition efficiency of 66.67% on mild steel and can thus be proposed for usage in industrial and commercial processes under a moderately acidic environment. Keywords: Corrosion, Corrosion Study Kit, Extract, Inhibitor, Mild Steel, Musa sapientum. 0150