Adsorption Study of Sorghum Vulgare as the Corrosion Inhibitor of Mild Steel in Tetraoxosulphate (VI) Acid Medium

This study deals with inhibition of corrosion of mild steel in tetraoxosulphate (vi) acid environment using the leaves of Sorghum vulgare. Extraction of Sorghum vulgare was done by cold maceration method. The extract was subjected to corrosion inhibition study using various concentration of the extract from 0.1g/l to 0.5g/l in 1M H2SO4 on the mild steel at the 50oC and 70oC using weight loss method. The results obtained revealed that the weight loss of the mild steel decreases as the concentration of the inhibitor increases while the temperature decreases. Inhibition efficiency calculated showed an increase from 28.29 % to 72.03 % at 50C as the concentration of the inhibitor increases. From the weight loss data, kinetic and thermodynamic parameters such as Ea, Hads, and Gads were calculated, the result showed that the mechanism of adsorption of Sulghum vulgare on the surface of the mild steel is by physical adsorption and it obeys Langmuir and Freundlich adsorption isotherms.