Biogenic corrosion inhibitor on mild steel protection in concentrated HCl medium

摘要

Biofouling/biocorrosion comprises adsorption, colonization, and undesirable accumulation of molecules, and microorganisms on i mmersed substrata which may have a wide range of destructing effects on man -made structures in the aquatic environment. Seaweed Turbinaria ornata (TO) extract, tested as green corrosion inhibitor on mild steel (MS) coupons in conc. HCl medium with efficien cy of 100% at 25 g l-1 in 5 min time. Antibacterial efficacy was performed against 16S rDNA identified marine biofilm bacteria (MBB) and human pathogenic bacteria (HPB). Maximum inhibition growth of 16 mm on MBB was observed in Bacillus megaterium (MBF14 - AB894827) and 20 mm on HPB in Escherichia coli (B5 - NCIM 2931). Similarly, a minimum of 10 mm on MBB was witnessed in Pseudomonas sp., (MBF9 - AB894829). Toxicity studies proved 50.0% LC50 at 500 μg ml -1 in 24 hrs, whereas Balanus amphitrite resulted in 100% mortality within 12 hrs. FT-IR and GC/MS results confirm, that 10-Octadecaonic acid is a major corrosion inhibitor for MS. As the T. ornata extract exhibited antifouling activity, it can be considered a novel antifoulant for developing antifouling formulation in the future.