Lepidium sativum Seeds as Green Inhibitor for Carbon Steel Corrosion in 1.0 M Hydrochloric Acid Solution

In this work, we are interested in studying the effect of the addition Lepidium sativum seeds (LSS) on the inhibition of the corrosion of carbon steel in acidic medium 1.0 M HCl. The inhibition of the corrosion reaction of carbon steel (CS) was performed using (LSS) in a 1.0 M hydrochloric acid medium using impedance spectroscopy (EIS) and potentiodynamic polarization (PDP). The phytochemical study revealed the existence of flavonoids, saponosides, tannins, alkaloids, sterols and polyterpenoids compounds. Inhibitory efficiency increases with increasing inhibitor concentration and decreases with increasing temperature. The experimental results show that Lepidium sativum seeds (LSS) is a good corrosion inhibitor where the maximum inhibition is around 90% at 2 g/L. PDP studies show that the Lepidium sativum seeds (LSS) act as mixed inhibitor. Corrosion current density decreased from 729 µAcm-2 (blank) to 125 µAcm-2 at 2 g/L (LSS). The studied inhibitor is adsorbed on the metal surface according to the model of the Langmuir adsorption isotherm