Corrosion Inhibition of Carbon Steel in Acidic Environment by Papaya Seed as Green Inhibitor

Abstract

Chemicals used presently for corrosion inhibitors in Industries are highly toxic to both human beings and environment. These inhibitors may cause the damage to organ system viz., kidneys or liver, or to disturb a biochemical process of an enzyme system at some site in the body. For papaya seed, a vegetable waste is found to act as a very good green inhibitor, in preventing acid corrosion of low-carbon construction steel. The study was made in 0.5 to 3 N H 2 SO 4 with the variation of concentration. An increase in inhibitor concentration decreases the rate of degradation. But there is an optimum concentration at which the inhibitor effect is maximum, beyond that the corrosion rate again increases. The adsorption study shows that the mechanism of corrosion inhibitor is due to physical adsorption, following Temkin adsorption isotherms. Electrochemical impedance spectroscopy study showed that the corrosion inhibition by the papaya seed is due to an increase in polarization resistance and impedance at metalsolution interface.

Performance of Methyl-5-Benzoyl-2-Benzimidazole Carbamate (Mebendazole) as Corrosion Inhibitor for Mild Steel in Dilute Sulphuric Acid

“…Alternatively, an increase in inhibition efficiency and decrease in corrosion rate with rise in temperature is indicative of chemisorption mechanism. e decreased inhibition efficiencies and higher corrosion rates obtained for the test specimens at elevated temperature as suggested by other researchers [19,22] were an indication that the critical concentration of anions required for the protection of mild steel in the corrosive media increases as the temperature increased.…”

“…Some of the most effective organic inhibitors include amines, sulphur compounds such as thioethers, thiourea, thioalcohols, hydrazine and thioamides, and heterocyclic nitrogen compounds [21]. Organic compounds are good inhibitors especially when they have functional electron-rich centres such as pi-electron in triple or conjugated double bonds and the presence of aromatic rings in their structures which serve as major adsorption centres [21][22][23].…”

Bio-Inhibitor on Corrosion Rate of ASTM A53 Steel in Marine Environment

“…It serves to add to the metal material in a corrosive environment so that it will inhibit and lower the rate of corrosion. In recent days, many alternative ecofriendly corrosion inhibitors have been developed, and they range from rare earth elements to organic compounds [2] Organic inhibitors can be obtained by extracting some of the ingredients found in nature. Some examples of natural materials that can be used as an organic inhibitor of banana peel, orange peel, dragon fruit peel, mangosteen peel, mango leaves, papaya leaves, and so forth.…”

“…Extracts of tobacco from twigs, stems, and leaves can protect steel and aluminium in saline solutions and strong pickling acids [1,5]. According to Paul and Koley [2], corrosion inhibition of carbon steel by few green inhibitors viz. garlic, yeast, pepper, and coffee or green inhibitors have been found to decrease the acid corrosion of mild steel by several folds with about 70-90% adsorption on the surface.…”

Protection of Aluminium Metal in 0.5 M HCl Environment by Mature Arecanut Seed Extracts: A Comparative Study by Chemical, Electrochemical and Surface Probe Screening Techniques

“…Therefore, these constituents are called green corrosion inhibitors. [8][9][10][11][12][13][14][15] Mature arecanut seed is one of the greenest products possessing hetero-atoms in their alkaloids, fibre, polysaccharides, fat and polyphenols contents. It is known that different types of arecanut contain different chemicals with different concentrations.…”