Joint Effect of Ethanol Extract of Orange Peel and halides on the Inhibition of the Corrosion of Aluminum in 0.1 M HCl: An approach to Resource Recovery

Richard Alexis UkpeReceived 08 November 2019/Accepted 12 November 2019 Resource recovery is the science of creating valuable products from waste. Successful resource recovery can reduce the burden of waste disposal. In this study, attempt is made to utilized ethanol extract of orange peel waste as a corrosion inhibitor for mild steel in solution of HCl. Ethanol extract behaved as adsorption inhibitor and the ranged obtained for the inhibition efficiencies of various concentrations of the extract were Calculated inhibition efficiency ranged from 35.03 to 60.08 %, 30.02 to 52.61%, 28.04 to 46.44 % and from 25.98 to 43.34 %. However, in the presence of KBr, KI and KCl, the enhanced range were 40.95 to 71. 02, 40.62 to 71.07 and from 84.22 to 88.12 %. Calculated synergistic parameters were greater than unity indicating that the adsorption of ethanol extract of orange peel waste was enhance by synergistic interaction with halides. Statistical analysis of variance indicated that temperature andconcentration have statistical weight of contributing to the inhibition efficiency of the extract. The prevalence of physical adsorption mechanism wasconfirmed through free energy of adsorption deduced from the fitted adsorption isotherms including Langmuir, Freundlich, Temkin, El Awardy et al and Dubinin-Radushkevich isotherms. However, joint adsorption of ethanol extract of orange peel waste did not obey the Temkin and Freundlich isotherm except the Langmuir isotherm, which displayed plots with negative slope (a reversal of what were obtained in the absence of the halides). FTIR of the extract indicated the presence of functional groups that are liken to those that are known good corrosion inhibitors

Inhibition of mild steel corrosion using Jatropha Curcas leaf extract

Jatropha Curcas leaf was investigated as a green inhibitor on the degradation of mild steel in 4 M HCl and 4 M H2SO4 aqueous solutions using gasometric technique. Mild steel coupons of dimension 2 × 1.5 cm were immersed in test solutions of uninhibited acid and also those with extract concentrations of 4 ml, 6 ml, 8 ml and 10 ml at 30 oC, for up to 30 minutes. The results showed that as the concentration of the extract increases, there was reduction in the corrosion rate. As the extract concentration increased from 4 ml to 10 ml at 30 minutes exposure, the volume of hydrogen gas evolved decreased from 19.1 cm3 to 11.2 cm3 in H2SO4 medium, while it reduced to 5 cm3 from 9 cm3 in HCl medium. Also, the metal surface-phytoconstituent interaction mechanism showed that 6 minutes is the best exposure time for the adsorption of the extract in both acidic media. The Jatropha Curcas leaf extract was adsorbed on the mild steel surface to inhibit corrosion, while the experimental data obtained at 30 minutes exposure in both acidic media were well fitted with the Langmuir adsorption isotherm. Hence, Jatropha Curcas leaf extract is a good and safe inhibitor in both acidic solutions

Opuntia ficus-indica (Nopal Extract) as Green Inhibitor for Corrosion Protection in Industrial Steels

Soluble extract from Opuntia ficus-indica (Nopal extract) has been proposed in this chapter as a green inhibitor due to its component called mucilage, which has the ability to retain water; for this reason, it has been used as metal corrosion protection in machinery pieces, tools and other metallic components that need to be stored for short periods. In this way, three industrial carbon steels (AISI 1018, 1045 and 4140) have been exposed in sulfuric acid (H2SO4) to evaluate the corrosion behavior with or without Nopal extract (NE). Some electrochemical techniques have been implemented to evaluate the corrosion inhibition efficiency (IE) such as DC linear polarization resistance (LPR) and AC electrochemical impedance spectroscopy (EIS). Results indicated a considerable superficial modification of steel in terms of dielectric constant and ion charge capacity. When the NE was added, the corrosion mechanism changed from localized to general attack, decreasing the corrosion rate in all cases. More susceptibility to fail by corrosion was observed in the 1045 carbon steel in comparison with the other two studied steels; these results were confirmed by the percentage of inhibitor’s efficiency of about 95%

Metolazone compound as corrosion inhibitor for API 5L X-52 steel in hydrochloric acid solution

The aim of this research is to evaluate the inhibitive effect of metolazone on API 5L X-52 steel in 2 M HCl solution using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization techniques within a temperature range of 303 to 323 K. Scanning electron microscopy (SEM) was also employed to study the morphology of the corroded coupons in 2 M HCl solution and in the presence of the inhibitor. The efficiency of the inhibition depends on the concentration of metolazone and reaction system temperature. The maximum inhibition efficiency values were 92.7 and 90.7%, respectively, for both EIS and polarization techniques at the temperature of 303 K. The electrochemical impedance spectra (EIS) studies reveal that the process of inhibition is through charge transfer. Potentiodynamic polarization (PDP) studies showed that metolazone is mixed-type inhibitor.  The metolazone adsorption characteristics on API 5L X-52 steel surface was found to be spontaneous and obeyed Langmuir adsorption isotherm and the mechanism of adsorption suggest chemisorptions. The inhibition efficiency of metolazone drug obtained by electrochemical methods was in good relationship with each other.                     KEY WORDS: Metolazone drug, API 5L X-52 Steel, SEM, Electrochemical, Corrosion inhibition   Bull. Chem. Soc. Ethiop. 2020, 34(2), 407-418 DOI: https://dx.doi.org/10.4314/bcse.v34i2.1

Temperature Effects on the Corrosion Inhibition of Mild Steel in Sulfuric Acid Solution by Acacia senegal Gum with Halide Ions

The effects of temperature on the inhibitive effect of naturally occurring Acacia senegal gum exudate on the corrosion of mild steel in sulfuric acid was studied between 35 and 70 °C using electrochemical impedance spectroscopy and potentiodynamic polarization methods. Findings showed that Acacia senegal gum exudate decreases the corrosion rate of mild steel. The inhibition efficiency declined with raising temperature above 35 °C. The increase in the corrosion rate with increasing temperature was observed for both uninhibited and inhibited systems. Addition of halide ions to the Acacia senegal gum exudate solution enhanced the corrosion inhibition efficiency because of synergistic effects, achieving higher performance with iodide ions as compared to bromide ions. However, the synergistic effects declined above 35 °C up to 70 °C due to temperature effects. It has been observed that increasing temperature adversely affected inhibition efficiencies of both Acacia senegal gum exudate and the synergy between Acacia senegal gum exudate and halide ions. Corrosion rates of mild steel, inhibition efficiencies of Acacia senegal gum exudate and the synergistic effects of halide ions from polarization and impedance measurements were consistent. Keywords: temperature, corrosion, mild steel, synergistic effects, Acacia senegal, gum exudate

Theobroma cacao Peel Extract as the Eco-Friendly Corrosion Inhibitor for Mild Steel

Corrosion control for metals has technical, economical, environmental, and aesthetical importance. The use of corrosion inhibitors from natural product is one of the best ways to slow the rate of corrosion of metals and alloys. The use of extract inhibitors from natural product is the best alternative because it does not contain heavy metals and is nontoxic, environmentally friendly, biodegradable, easy to obtain, inexpensive, and available in large quantities. The organic compounds contained in the extracts of natural products such as tannins, amino acids, phenolics, and alkaloids contain heteroatomic groups, which can inhibit corrosion rate and are interesting to study. With the development of science and technology, many methods are used to protect the corrosion, such as electroplating and coating, and organic inhibitor shows real promise such as Theobroma cacao peel extract. Although substantial research has been devoted to corrosion inhibition by plant extracts, reports on the detailed mechanisms of the adsorption process and identification of the active ingredient are still scarce. The addition of polar extract of cacao peel into a solution of HCl 1.5 M is very effective to reduce the attack surface corrosion on mild steel and can maintain its mechanical properties. This chapter consciously restricts itself mainly to plant materials, especially Theobroma cacao peel extract, as green corrosion inhibitors

Effect of Terminalia catappa Leaves Extract on Corrosion of Mild Steel using Response Surface Methodology

Effect of Terminalia catappa leaves (TCL) extract in inhibiting corrosion of mild steel was investigated. In order to obtain the maximum inhibition efficiency, optimization of the process variables affecting corrosion of mild steel was carried out using the Box – Behnken Design plan and desirability function of Response Surface Methodology (RSM). The three parameters - varied include; TCL concentration (inhibitor), immersion time, and temperature and there effects in corrosion inhibition were established. The optimum conditions predicted from the quadratic model were inhibitor’s concentratrion (0.39 g/l), exposure time (8.68 hours), and temperature (36.06 oC) with the inhibition efficiency of 91.95 %. The data fitted well to the quadratic model which was validated. Adsorption of the extract’s component on the mild steel was responsible for the inhibitory effect of the TCL extract.The results showed that 97.92% of the total variation in the inhibition efficiency of TCL can be connected to the variables studied. Keywords: Mild steel, acid, Terminalia catappa, Corrosion, Response surface methodology (RSM)

Assessing the deterioration behaviour of mild steel in 2 M sulphuric acid using Bambusa glauscescens

The study investigated the deterioration of mild steel in 2 M sulphuric acid solution in the presence of Bambusa glauscescens extract using gasometric technique. Steel coupons measuring 4 cm by 1.5 cm were immersed in test solutions of uninhibited acid and also those containing extract concentrations of 60,100 and 140 cm3 at a temperature of 333K for 60 minutes. The volumes of hydrogen gas evolved from the reaction were documented and analyzed. The analysis showed that while extract concentration was increasing, H2 evolution and % I.E increased. There was also a corresponding reduction in corrosion rate as extract concentration increased. The decrease in corrosion rate was observed to follow in order of increasing extract concentration. Phytochemical-metal interaction mechanism was best described by Freundlich isotherm, with the 4 and 12 minutes curve becoming the best and worst contact time for the extract phytochemicals to suitably adsorb to metal surface for all concentrations used. An expression suitable for calculating corrosion rate values once concentration is known was also deduced. Furthermore, the microstructural studies revealed that increasing the extract concentration resulted in significant reduction in the dominant coarsening of the oxide of iron phase, while the pearlite and ferrite phases became finely disperse

Corrosion inhibition potentials of Roselle (Hibiscus sabdariffa) in tetraoxosulphate (VI) acid solution

The harmful effects of chemical based corrosion inhibitors on man and the ecosystem prompted the search for alternatives that are non hazardous to the environment.Therefore, the corrosion inhibition potentials of the leaves and flowers of the green variety of Roselle (Hibiscus sabdariffa) were evaluated.This was undertaken mainly to investigate the effectiveness of the leaves and flowers of Roselle in mitigating the corrosion of mild steel in acidic medium. The gravimetric method of corrosion measurement was used to evaluate the corrosion inhibition potentials of the plant parts. The results showed that the leaves and flowers of the plant can effectively be used to mitigate the corrosion of metals in acidic medium. The maximum inhibition efficiencies of the leaves and flower extracts of the plant were 27.94 % and 22.81 % respectively. The leaves and flowers of the plant were more efficient on the first eight days of application