Effect of crude methanolic extract of Lawsonia inermis for anti-biofilm on mild steel 1010 and its effect on corrosion in a re-circulating wastewater system

Abstract

The natural product Catharanthus roseus and Lawsonia inermis leaf extract enhancement in the anti-corrosion potential green corrosion inhibitor (GIC) for Bacillus oleronius EN9 biofilm forms on mild steel (MS) in re-circulating water environment is demonstrated. This re-circulating water was enhancing the corrosion due to the temperature, pH, salinity, and chloride. Therefore, we need to improve the performance of the inhibitors. The chosen GIC inhibition was examined by antibacterial assay, weight loss, surface, and electrochemical analysis. L. inermis has shown the antibacterial activity (75%) against the corrosive bacteria Bacillus oleronius than the C. roseus (44%) optimum concentration of 20 ppm. L. inermis was selected for further studies and it reduces the corrosion rate up to 75 % in the 1% NaCl system. Scanning electron microscopy confirms the formation of the protective film on MS and GC–MS confirmed the presence of complex molecules of L. inermis. Therefore, the current work concluded that green corrosion inhibitor is suitable for the inhibition of biocorrosion of MS in the re-circulating system and a promising alternative for chemical inhibitor.

Keywords

• Re-circulating water
• Lawsonia inermis
• Green inhibitor
• Bacteria