Biogenic corrosion inhibitor on mild steel protection in concentrated HCl medium

Turbinaria ornata(TO) extract was tested as green corrosion inhibitor on mild steel (MS) coupons in conc. HCl medium with an efficiency of 100% at 25 g l−1during 5 min exposure. Antibacterial efficacy performed against 16 S rDNA identified marine biofilming bacteria (MBB) and human pathogenic bacteria (HPB). Maximum inhibition growth was 16 mm on MBB observed inBacillus megaterium(MBF14 - AB894827) and 20 mm on HPB inEscherichia coli(B5 - NCIM 2931). Similarly, minimum of 10 mm on MBB witnessed inPseudomonassp., (MBF9 - AB894829). Toxicity studies proved 50.0% LC50at 500 μg ml−1in 24 hrs, whereasBalanus amphitriteresulted in 100% mortality within 12 hrs. Results including weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy, FT-IR and GC-MS confirm 10-Octadecaonic acid as a major corrosion inhibitor fromT. ornataand is discovered as a novel antifoulant. Anticorrosion formulation will become available soon.