Corrosion induced by aqueous environments containing carbon dioxide (CO 2) is a well-documented i... more Corrosion induced by aqueous environments containing carbon dioxide (CO 2) is a well-documented issue in the oil and gas industries, particularly affecting transportation via steel pipelines. Operational conditions during transportation, including temperature, flow rate, and solution chemistry, significantly influence the corrosion inhibition mechanism. In this study, the corrosion inhibition behavior of API 5L X52 steel in a 3.5 wt% NaCl brine solution saturated with carbon dioxide was investigated using 1, 3-diazole glyoxaline (DG) as an organic inhibitor. Both gravimetric and electrochemical methods were employed to assess corrosion rates and inhibitor efficiency across various temperatures, inhibitor concentrations, and rotational speeds. The outcomes showed that inhibition efficiency increased with inhibitor concentration and temperature. From weight loss measurements, the maximum inhibition efficiency was 98.58 % at 3 × 10 − 4 M of DG and 60 • C. The polarization investigations showed a reduction in the anodic and cathodic curves in the presence of the inhibitor. This suggested a mixed-type inhibition mechanism. The electrochemical impedance spectroscopy results showed an improvement in charge transfer resistance due to the formation of a protective layer on the metal surface. In addition, AFM, SEM, contact angle, hardness, and roughness measurements proved the enhancement in surface morphology due to the presence of DG.
This study aimed to evaluate the effectiveness of 3-((dicyclohexylamino) methyl)-5-(4-((3, 4-dime... more This study aimed to evaluate the effectiveness of 3-((dicyclohexylamino) methyl)-5-(4-((3, 4-dimethoxybenzylidene) amino) phenyl)-1, 3, 4-oxadiazole-2(3H)-thione (DMOT) in inhibiting the deterioration of mild steel in a 1 M HCl solution. Weight loss and electrochemical measurements were used to assess the inhibition performance and synthesis of DMOT. The characterization of DMOT was conducted through NMR and FTIR measurements, while SEM and AFM were used in the surface analysis. DFT calculations were used to investigate the chemical and theoretical properties of DMOT. The results of electrochemical measurements showed that the inhibition efficiency increased as the concentration of the inhibitor increased, with an optimal concentration reaching an inhibition efficiency of 99.17%. Polarization curves revealed that DMOT molecules behaved as a mixed-type inhibitor, with adsorption following the isotherm of Langmuir. The adsorption of DMOT on the corroded metal's surface was verified by SEM and AFM investigations. Using quantum chemical calculations, the quantum chemical properties of the DMOT were evaluated.
The aim of the present work is to study the corrosion inhibition of Al 7475 alloy by an expired m... more The aim of the present work is to study the corrosion inhibition of Al 7475 alloy by an expired mouthwash drug (EMWD) in a 1 M HCl solution. The corrosion rate was optimized by the Doehlert experimental design at various temperatures, concentrations of inhibitor, and rotational velocity. The corrosion behavior was investigated by mass loss, Tafel potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques. SEM, MOMT, XRD, FT-IR spectrum, and drop wettability measurement were used in characterizations of EMWD and surface morphology. Optimum conditions for corrosion control of EMWD on aluminum were 44.12 ◦C, 141.71 mL/L of EMWD per liter of acid, and 234.89 rpm. Maximum corrosion inhibition efficiency was 84.717% at higher levels of temperature and inhibitor concentration. It is observed that EMWD follows the Langmuir Adsorption Isotherm with negative values of ΔGads o , proposing a stable spontaneous inhibition process. The inhibitor efficiency increased as the inhibitor concentration increased. Moreover, increasing the solution temperature and rotational velocity had an adverse influence on inhibitor efficiency. The results of mass loss were in good agreement with potentiodynamic polarization and EIS. Polarization diagrams revealed that the inhibitor acts as a mixed-type inhibitor. It could be concluded that response surface Doehlert design (RSDD) was adequately applicable in the optimization of corrosion inhibition process variables and that EMWD sufficiently inhibited the corrosion of the aluminum at the studied conditions. Simulation of the EMWD molecules adsorption on the metal surface by quantum chemical theoretical studies was a powerful tool for supporting experimental outcomes.
Maǧallaẗ al-handasaẗ wa-al-tiknūlūǧiyā, Aug 31, 2010
1100 Al specimens were anodically oxidized in different concentrations of tartaric acid-tartrate ... more 1100 Al specimens were anodically oxidized in different concentrations of tartaric acid-tartrate solution (pH=7) in 1, 1.75, 3.25 and 4 wt % at temperatures of 30, 37.5, 52.5 and 60 ºC by applying a range of potentials of 30, 37.5, 52.5 and 60 V at exposure times of 40, 47.5, 62.5 and 70 min.. These four variables are manipulated through the experimental work using Box-Wilson experimental design where second order polynomial model was proposed to correlate the studied variables with the thickness of anodic film of aluminum alloy (1100) to estimate the coefficients of the proposed polynomial adopted via statistica software. Optimum conditions for achieving the maximum film thickness are obtained from optimizing the above correlation and are found as follows: temp. = 44 ºC, acid conc. = 2.8 wt %, voltage = 43.6 V, time = 54.6 min.. Stagnate Solutions of 3, 5, 10 and 25 wt % Nacl at 25ºC have been investigated using polarization technique at optimum conditions for anodizing. The most important feature achieved was the great difference in behavior between the anodic polarization curves for bare and anodized aluminum in different concentrations of Nacl solutions. The corrosion rates for anodized specimens are lower than those for unanodized ones. The polarization behavior of anodizing specimens shows that the breakdown potentials are shifted to more noble direction than bare specimens which is more pronounced in 25 wt % Nacl solution due to anodizing.
Iraqi Journal of Chemical and Petroleum Engineering
Previously, many empirical models have been used to predict corrosion rates under different CO2 c... more Previously, many empirical models have been used to predict corrosion rates under different CO2 corrosion parameters conditions. Most of these models did not predict the corrosion rate exactly, besides it determined effects of variables by holding some variables constant and changing the values of other variables to obtain the regression model. As a result the experiments will be large and cost too much. In this paper response surface methodology (RSM) was proposed to optimize the experiments and reduce the experimental running. The experiments studied effects of temperature (40 – 60 °C), pH (3-5), acetic acid (HAc) concentration (1000-3000 ppm) and rotation speed (1000-1500 rpm) on CO2 corrosion performance of the regression model calculated by RSM. The experiments were conducted in saturated solution of CO2 with 3.5 % NaCl solution. STATISTICA program version 10 was used for data analysis. In conclusion a quadratic model is proposed to predict the effect of mentioned variables in ...
Taguchi experimental design (TED) is applied to find the optimum effectiveness of aqueous Red Pom... more Taguchi experimental design (TED) is applied to find the optimum effectiveness of aqueous Red Pomegranate Peel (RPP) extract as a green inhibitor for the corrosion of mild steel in 2M H3PO4 solution. The Taguchi methodology has been used to study the effects of changing, temperature, RPP concentration and contact period, at three levels. Weight-loss measurements were designed by construction a L9 orthogonal arrangement of experiments. Results of the efficiencies of inhibition were embraced for the signal to noise proportion & investigation of variance (ANOVA). The results were further processed with a MINITAB-17 software package to find the optimal conditions for inhibitor usage. Second order polynomial model was used for experimental data fitting. Optimum conditions for achieving the maximum corrosion inhibition efficiency are obtained from optimizing the above model and are found as follow: 39.66 °C temperature of acidic media, 38.29 ml/L inhibitor concentration and 2.95 h cont...
Due to the growing concern about corrosion problems caused by acidic attacks, the anticorrosive p... more Due to the growing concern about corrosion problems caused by acidic attacks, the anticorrosive properties of synthetic corrosion inhibitor has been studied. The present work assessed the synthesis and inhibition performance of 3-((dicyclohexyl amino)methyl)-5-(4-((2-hydroxybenzylidene) amino phenyl)-1, 3, 4-oxadiazole-2(3H)-thione (DHOT) on the corrosion of mild steel in 1 M HCl solution through weight loss and electrochemical measurements. DHOT was characterized using FTIR and 1H NMR measurements. Surface analysis was carried out using SEM and AFM. Chemical theoretical studies of DHOT were performed using density functional theory (DFT) calculations. Electrochemical measurement results showed that corrosion inhibition increased as inhibitor concentration increased, achieving a significant inhibition efficiency of 98.86% at optimum conditions. Polarization curves indicated that molecules of DHOT acted as a mixed-type inhibitor, and their adsorption process obeyed the Langmuir isotherm. Examination of corroded steel surface by SEM and AFM confirmed the adsorption of DHOT on metal surface. Chemical quantum calculations were used to determine the electronic properties of the DHOT and to explain inhibitor/metal surface interactions.
Metal corrosion is a destructive process for many industrial operations, including oil well acidi... more Metal corrosion is a destructive process for many industrial operations, including oil well acidizing and acid pickling. Therefore, numerous efforts made by many researchers to control the steel corrosion. In the present work, A (E)-4-(((4-(5-mercapto-1,3,4-oxadiazol-2-yl) phenyl) amino) methyl)-2-methoxyphenol (MOPM) has been synthesized and characterized as a new corrosion inhibitor for mild steel in 0.1 M hydrochloric acid. FTIR and 1 HNMR were used in the diagnosis of MOPM, while electrochemical polarization technique was employed to test the performance of inhibitor at various temperatures and inhibitor concentrations. Electrochemical studies showed that MOPM acts as a mixed-type inhibitor with a maximum inhibition efficiency of 93.2% at 30 ◦C and 0.5 M MOPM. Furthermore, the presence of MOPM increased the polarization resistance and depressed the corrosive action. The inhibitory action of MOPM over mild-steel surface was according to Langmuir adsorption isotherm. The calculated free energy of adsorption was − 20.663 kJ.mol− 1 that suggested the spontaneous physical adsorption mode. Value of activation energy was higher in the presence of MOPM, which indicated the formation of protective layer on the metal surface. Quantum chemical calculations that carried out to the chemical structure of MOPM provides a reasonable support to the experimental results.
International Journal of Environmental Science and Technology
The present work evaluated the potential of two types of wastes, fennel seed and garlic peels, to... more The present work evaluated the potential of two types of wastes, fennel seed and garlic peels, to uptake Congo red dye from aqueous solutions. Several techniques, like SEM, FTIR, and BET surface area, were utilized to characterize the two biomass materials used as biosorbents. The main effective parameters, namely initial concentrations (10-100 mg L −1), pH (4-9), contact time (0-60 min), and adsorbent/biosorbent dose (0.01-2.0 g), were examined. Equilibrium isotherms like the Langmuir, Freundlich, Temkin, and Harkins-Hasely models were modeled. The experimental data fit well with the Langmuir model for both GP and FSS. The maximum adsorption capacities obtained were 15.22 mg g −1 and 172.43 mg g −1 for GP and FSS, respectively. Two kinetic models, the pseudo first-order kinetic model and the pseudo-second-order kinetic model, were studied, and the data obtained from experimental work followed the pseudo-second-order kinetic model for both GP (R 2 = 0.9991) and FSS (R 2 = 0.9995), respectively. The final results indicated that fennel seed could be an alternative material and more efficient biosorbent for dye removal from contaminated water.
Iraqi Journal of Chemical and Petroleum Engineering
The corrosion behavior of bare and chemical conversion coated (through anodizing) aluminum ASA 60... more The corrosion behavior of bare and chemical conversion coated (through anodizing) aluminum ASA 606 I in stagnant chromic acid solutions . Solutions of 2, 6 & J O wt. % Cr03 at 45°C, have been investigated using polarization technique. The anodizing experiments were conducted under fixed conditions of 35 minute exposure time and 30 volt supplied voltage. The most important feature achieved was the great difference in behavior between the anodic polarization curves for bare and anodized aluminum in different concentrations of chromic acid solutions.
Corrosion inhibition is an extensive field of study, and its progression is gaining traction amon... more Corrosion inhibition is an extensive field of study, and its progression is gaining traction among researchers. This paper describes a study to synthesize and characterize a novel class of organic corrosion inhibitor called (3, 5dimethyl-1H-pyrazol-1-yl) (4-((4-chlorobenzy-lidene) amino) phenyl) methanone) (DPCM). The structure of DPCM was determined using FTIR, 1 H NMR and 13 C NMR techniques. The effectiveness of DPCM was tested on carbon steel in 1 M HCl using electrochemical and weight loss methods, and it was found that the inhibition efficiency increased with increasing temperature and DPCM concentration. The highest inhibition efficiency of 89.5% was achieved at 60 • C and 400 ppm DPCM. The inhibition action of DPCM molecules was achieved by blocking the metal surface by means of the adsorption of inhibitor molecules obeying the Langmuir adsorption isotherm. Adsorption-free energy indicates a spontaneous chemical adsorption process. The polarization test results clarified a mixed effect of DPCM on anodic and cathodic reactions. Electrochemical impedance spectroscopy indicated an increase in metal resistance in the presence of an inhibitor. The formation of a protective layer was confirmed by SEM and AFM analysis. Density functional theory (DFT) simulation has been used to determine the relationship between molecular configuration and their inhibition efficiencies.
1H-pyrazol-1-y1) (4-((3,4-dimethoxybenzylidene) amino) phenyl) methanone (DPMM) has been effectiv... more 1H-pyrazol-1-y1) (4-((3,4-dimethoxybenzylidene) amino) phenyl) methanone (DPMM) has been effectively synthesized and characterized. FTIR and NMR have been used to diagnose DPMM's functional groups and components. Electrochemical and weight loss methods were used to assess the inhibitor efficacy for low-carbon steel in 1 M HCl. By raising the temperature and DPMM concentrations, the inhibition efficiency improved. The inhibition efficiency approached 95.5 % at 400 ppm of DPMM and 60 • C. The efficiency of the inhibitor was ascribed to the formation of a protective mono-layer on the steel surface. The mechanism of the adsorption process was examined using the Langmuir adsorption isotherm, whereas the mechanism of inhibition was examined using theoretical quantum chemical simulations. The results revealed that the DPMM was the donor of electron, while the steel surface was an electron acceptor.
An aqueous extract of onion and garlic leaf extract (OGLE) blend was employed to retard low-carbo... more An aqueous extract of onion and garlic leaf extract (OGLE) blend was employed to retard low-carbon steel (LCS) corrosion in 1 M HCl for the first time. The corrosion inhibition ability of OGLE has been tested via weight loss and electrochemical techniques. Firstly, onion and garlic leaf extracts are separately tested at 30 • C using a Doehlert experimental design to find the optimum concentration of each extract. Secondly, a full-factorial design is used to evaluate the corrosion rate at different blend concentrations and temperatures. Experimental results revealed that the OGLE blend can be considered a good green inhibitor. At 300 ppm OGLE and 60 • C, the maximum blend corrosion inhibition efficacy was 96.65 %. The Langmuir adsorption isotherm demonstrates that OGLE adsorbed with negative heat of adsorption, suggesting a stable monolayer developed spontaneously on LCS. According to electrochemical experiments, when OGLE is present, corrosion current densities are greatly reduced.
1H-pyrazol-1-yl m (4-((4-hydroxybenzylidene) amino) phenyl) methanone (DPHM) has been effectively... more 1H-pyrazol-1-yl m (4-((4-hydroxybenzylidene) amino) phenyl) methanone (DPHM) has been effectively synthesized and characterized. The diagnosis of functional groups and constituents of DPHM has been conducted by FTIR, 1 H NMR, and 13 C NMR. The inhibitor efficacy for low-carbon steel in 1 M HCl was evaluated by using weight loss and electrochemical techniques. The inhibition efficiency was increased with increasing the temperature and DPHM concentrations. The inhibition efficiency approaches a maximum value of 89.5% at 400 ppm of DPHM and 60 • C. The efficiency of the inhibitor was attributed to the formation of a protective mono-layer on the steel surface. The Langmuir adsorption isotherm was used to inspect the adsorption process mechanism. Theoretical quantum chemical simulations were used to investigate the mechanism of inhibition. The results revealed that the DPHM was the donor of electron, while the steel surface was an electron acceptor. Mathematical and statistical modelling were used as powerful tool for data representation. Exponential model, with 0.992 correlation coefficient, was the most accurate one.
Electrocoagulation method is carried out to remove methyl orange from synthetic wastewater using ... more Electrocoagulation method is carried out to remove methyl orange from synthetic wastewater using iron-iron electrodes as anode and cathode. Effects of several experimental parameters treatment of methyl orange (MO) dye removal such as pH, initial concentration, current density and electrode ' s distance have been studied. The Taguchi method using L 16 orthogonal array experimental design was applied to optimize the experimental operating conditions that varied at four levels, initial pH (4-10), current density (1-4 mA/cm 2), electrode distance (0.5-1.5 cm), and initial concentration (25-100 mg/L), while the removal efficiency (%R) was considered as the response variable. The Taguchi method based on the average S/N graph method, in combination with analysis of variance (ANOVA), was applied to determine the significant parameters that affect the dye removal. The optimum conditions for removal of MO were determined to be initial concentration (25 mg/L) , electrode distance (0.5 cm) , pH (8), and current density (3 mA/cm 2). The Acidity pH factor represents the most significant factor affecting on removal of MO. The optimum response variables are 97.19 and 97.24% for observed and predicted values, respectively at 39.7575 S/N ratio. As a result, an excellent removal of methyl orange dye from wastewater was attained depending upon the best parametric conditions that obtained from Taguchi method.
In this paper, anodizing process of 5854 aluminum-magnesium alloy (5854Al-Mg) in oxalic acid (OXA... more In this paper, anodizing process of 5854 aluminum-magnesium alloy (5854Al-Mg) in oxalic acid (OXA) was investigated in the absence and presence of 5-sulfosalicylic acid (SSA). Electrochemical and surface morphological techniques were used to study the corrosion resistance and film characterizations. Furthermore, the influence of sealing time on corrosion rate was addressed. It was observed that the corrosion current density decreased with the addition of SSA and increasing with sealing time. Maximum coating efficiency was 90.72% in the presence of 0.09 M SSA at 50 min of sealing period. The open circuit potential (OCP) was shifted to a more positive direction indicating the formation of passive film. While, the values of polarization resistance (Rp) of aluminum alloy were higher in the presence of SSA. Scanning electron microscopy (SEM) showed that the addition of SSA improved the surface properties. The anodizing of 5854 Al alloy in the presence of SSA resulted in the formation of anodic films of higher hardness, less roughness, and high film thickness as compared with OXA alone. Reaction kinetics models were proposed. The best fitting was obtained with zero-order reaction kinetics. Half-life time was increased from 9.05 to 123.3 min in case of OXA/SSA anodizing process. In addition, four mathematical equations were suggested to represent the corrosion current density as a function of time. Power model was the most significant one as compared with linear, second order, and exponential models.
The behavior of the corrosion inhibition of mild steel in a brine produced water saturated with c... more The behavior of the corrosion inhibition of mild steel in a brine produced water saturated with carbon dioxide using 1, 3, 5, 7-tetraazaadamantane (TAA) as a heterocyclic organic inhibitor was investigated. Gravimetrical and electrochemical methods were used to determine corrosion rates and the experimental work were mathematically designed using Doehlert experimental design (DED). Corrosion rate was optimized as a function of TAA dosage, temperatures, and rotation rate. Maximum corrosion inhibition efficiency was 92% at optimum conditions. TAA was adsorbed chemically and spontaneously on metal surface according to Langmuir isotherm. These results were confirmed by scanning electron microscopy (SEM), optical microscopy, UV–Vis spectral, and FTIR techniques. Quantum chemical analysis was used as a theoretical tool. It was found that the protonated state of TAA was more efficient than the ground state.
Corrosion inhibition of C6.9 mild steel alloy in 2M H3PO4 solution by extracted aqueous of red po... more Corrosion inhibition of C6.9 mild steel alloy in 2M H3PO4 solution by extracted aqueous of red pomegranate peels (EARPP) as an green inhibitor have been investigated using Half – cell potentials measurments, electrochemical polarization technique measurments has been utilized to assess the corrosion parameters: Icorr., Ecorr., βc , βa and RP have been calculated using Extrapolation of cathodic and anodic Tafel plot and resistance of linear polarization technique. Experimental design of Taguchi procedure (EDTP) was applied for distribution of the polarization experiments conditions. The data obtained from the utilized two techniques are in great concurrence with each other. These investigations have demonstrated that EARPP is a very good "green", blended sort inhibitor. The inhibition procedure was ascribed to the formation of an adsorbed layer on the surface of metal that protects the metal against corrosive agents. The most important feature achieved was the polarization ...
The behavior of anodic porous alumina film formed on an aluminum surface by anodizing in chromic ... more The behavior of anodic porous alumina film formed on an aluminum surface by anodizing in chromic acid solutions was optimized using Box-Wilson experimental design. The film thickness was correlated as a function of temperature, acid concentration, applied voltage, and time. A mathematical model was suggested and optimized. Results of coating thickness indicate that both temperature and time play an important role in the anodizing process. The interaction effect of variables on the film thickness is less pronounced compared with the effect of the main variables. Optimum film thickness obtained during the anodizing process was 10.43 µm at the optimum value of temperature (45 °C) and time (68 min). The polarization measurement of anodized aluminum ASA 6061 in chromic acid shows a high corrosion resistance in the presence of coating. The results confirmed by using surface morphology investigations.
The inhibition of X80 steel corrosion by a 3-Methoxypropyl-amine (MOPA) as a new corrosion inhibi... more The inhibition of X80 steel corrosion by a 3-Methoxypropyl-amine (MOPA) as a new corrosion inhibitor in saline solution (3.5 wt% NaCl) was optimized at different temperatures, inhibitor concentrations, the rotation speed of the solution and pH. Mass loss and polarization measurements were used to evaluate the corrosion rate and other kinetics parameters. The inhibition performance of MOPA was optimized by factorial experimental designs. Optimum conditions for the minimum corrosion rate were 12.89°C, 8.63 g/l, 1097.69 rpm, pH 4.03. It was observed that MOPA follows the Langmuir adsorption isotherm with negative values of ΔG ads o , proposing a spontaneous and stable inhibition process. According to ΔG ads o values, a physical adsorption was suggested. The inhibitor efficiency increased with increasing the inhibitor concentration and pH of the solution. Moreover, increasing the solution temperature and rotation velocity had an adverse influence on inhibitor efficiency. Results of mass loss technique were agreed with the polarization one. Polarization diagrams revealed that the inhibitor affects as a mixed-type inhibitor. Surface morphology and FTIR spectrum studies were confirmed the effectiveness of the inhibitor. A theoretical quantum chemical simulation was a powerful tool for the optimization of the MOPA structure.
Corrosion induced by aqueous environments containing carbon dioxide (CO 2) is a well-documented i... more Corrosion induced by aqueous environments containing carbon dioxide (CO 2) is a well-documented issue in the oil and gas industries, particularly affecting transportation via steel pipelines. Operational conditions during transportation, including temperature, flow rate, and solution chemistry, significantly influence the corrosion inhibition mechanism. In this study, the corrosion inhibition behavior of API 5L X52 steel in a 3.5 wt% NaCl brine solution saturated with carbon dioxide was investigated using 1, 3-diazole glyoxaline (DG) as an organic inhibitor. Both gravimetric and electrochemical methods were employed to assess corrosion rates and inhibitor efficiency across various temperatures, inhibitor concentrations, and rotational speeds. The outcomes showed that inhibition efficiency increased with inhibitor concentration and temperature. From weight loss measurements, the maximum inhibition efficiency was 98.58 % at 3 × 10 − 4 M of DG and 60 • C. The polarization investigations showed a reduction in the anodic and cathodic curves in the presence of the inhibitor. This suggested a mixed-type inhibition mechanism. The electrochemical impedance spectroscopy results showed an improvement in charge transfer resistance due to the formation of a protective layer on the metal surface. In addition, AFM, SEM, contact angle, hardness, and roughness measurements proved the enhancement in surface morphology due to the presence of DG.
This study aimed to evaluate the effectiveness of 3-((dicyclohexylamino) methyl)-5-(4-((3, 4-dime... more This study aimed to evaluate the effectiveness of 3-((dicyclohexylamino) methyl)-5-(4-((3, 4-dimethoxybenzylidene) amino) phenyl)-1, 3, 4-oxadiazole-2(3H)-thione (DMOT) in inhibiting the deterioration of mild steel in a 1 M HCl solution. Weight loss and electrochemical measurements were used to assess the inhibition performance and synthesis of DMOT. The characterization of DMOT was conducted through NMR and FTIR measurements, while SEM and AFM were used in the surface analysis. DFT calculations were used to investigate the chemical and theoretical properties of DMOT. The results of electrochemical measurements showed that the inhibition efficiency increased as the concentration of the inhibitor increased, with an optimal concentration reaching an inhibition efficiency of 99.17%. Polarization curves revealed that DMOT molecules behaved as a mixed-type inhibitor, with adsorption following the isotherm of Langmuir. The adsorption of DMOT on the corroded metal's surface was verified by SEM and AFM investigations. Using quantum chemical calculations, the quantum chemical properties of the DMOT were evaluated.
The aim of the present work is to study the corrosion inhibition of Al 7475 alloy by an expired m... more The aim of the present work is to study the corrosion inhibition of Al 7475 alloy by an expired mouthwash drug (EMWD) in a 1 M HCl solution. The corrosion rate was optimized by the Doehlert experimental design at various temperatures, concentrations of inhibitor, and rotational velocity. The corrosion behavior was investigated by mass loss, Tafel potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques. SEM, MOMT, XRD, FT-IR spectrum, and drop wettability measurement were used in characterizations of EMWD and surface morphology. Optimum conditions for corrosion control of EMWD on aluminum were 44.12 ◦C, 141.71 mL/L of EMWD per liter of acid, and 234.89 rpm. Maximum corrosion inhibition efficiency was 84.717% at higher levels of temperature and inhibitor concentration. It is observed that EMWD follows the Langmuir Adsorption Isotherm with negative values of ΔGads o , proposing a stable spontaneous inhibition process. The inhibitor efficiency increased as the inhibitor concentration increased. Moreover, increasing the solution temperature and rotational velocity had an adverse influence on inhibitor efficiency. The results of mass loss were in good agreement with potentiodynamic polarization and EIS. Polarization diagrams revealed that the inhibitor acts as a mixed-type inhibitor. It could be concluded that response surface Doehlert design (RSDD) was adequately applicable in the optimization of corrosion inhibition process variables and that EMWD sufficiently inhibited the corrosion of the aluminum at the studied conditions. Simulation of the EMWD molecules adsorption on the metal surface by quantum chemical theoretical studies was a powerful tool for supporting experimental outcomes.
Maǧallaẗ al-handasaẗ wa-al-tiknūlūǧiyā, Aug 31, 2010
1100 Al specimens were anodically oxidized in different concentrations of tartaric acid-tartrate ... more 1100 Al specimens were anodically oxidized in different concentrations of tartaric acid-tartrate solution (pH=7) in 1, 1.75, 3.25 and 4 wt % at temperatures of 30, 37.5, 52.5 and 60 ºC by applying a range of potentials of 30, 37.5, 52.5 and 60 V at exposure times of 40, 47.5, 62.5 and 70 min.. These four variables are manipulated through the experimental work using Box-Wilson experimental design where second order polynomial model was proposed to correlate the studied variables with the thickness of anodic film of aluminum alloy (1100) to estimate the coefficients of the proposed polynomial adopted via statistica software. Optimum conditions for achieving the maximum film thickness are obtained from optimizing the above correlation and are found as follows: temp. = 44 ºC, acid conc. = 2.8 wt %, voltage = 43.6 V, time = 54.6 min.. Stagnate Solutions of 3, 5, 10 and 25 wt % Nacl at 25ºC have been investigated using polarization technique at optimum conditions for anodizing. The most important feature achieved was the great difference in behavior between the anodic polarization curves for bare and anodized aluminum in different concentrations of Nacl solutions. The corrosion rates for anodized specimens are lower than those for unanodized ones. The polarization behavior of anodizing specimens shows that the breakdown potentials are shifted to more noble direction than bare specimens which is more pronounced in 25 wt % Nacl solution due to anodizing.
Iraqi Journal of Chemical and Petroleum Engineering
Previously, many empirical models have been used to predict corrosion rates under different CO2 c... more Previously, many empirical models have been used to predict corrosion rates under different CO2 corrosion parameters conditions. Most of these models did not predict the corrosion rate exactly, besides it determined effects of variables by holding some variables constant and changing the values of other variables to obtain the regression model. As a result the experiments will be large and cost too much. In this paper response surface methodology (RSM) was proposed to optimize the experiments and reduce the experimental running. The experiments studied effects of temperature (40 – 60 °C), pH (3-5), acetic acid (HAc) concentration (1000-3000 ppm) and rotation speed (1000-1500 rpm) on CO2 corrosion performance of the regression model calculated by RSM. The experiments were conducted in saturated solution of CO2 with 3.5 % NaCl solution. STATISTICA program version 10 was used for data analysis. In conclusion a quadratic model is proposed to predict the effect of mentioned variables in ...
Taguchi experimental design (TED) is applied to find the optimum effectiveness of aqueous Red Pom... more Taguchi experimental design (TED) is applied to find the optimum effectiveness of aqueous Red Pomegranate Peel (RPP) extract as a green inhibitor for the corrosion of mild steel in 2M H3PO4 solution. The Taguchi methodology has been used to study the effects of changing, temperature, RPP concentration and contact period, at three levels. Weight-loss measurements were designed by construction a L9 orthogonal arrangement of experiments. Results of the efficiencies of inhibition were embraced for the signal to noise proportion & investigation of variance (ANOVA). The results were further processed with a MINITAB-17 software package to find the optimal conditions for inhibitor usage. Second order polynomial model was used for experimental data fitting. Optimum conditions for achieving the maximum corrosion inhibition efficiency are obtained from optimizing the above model and are found as follow: 39.66 °C temperature of acidic media, 38.29 ml/L inhibitor concentration and 2.95 h cont...
Due to the growing concern about corrosion problems caused by acidic attacks, the anticorrosive p... more Due to the growing concern about corrosion problems caused by acidic attacks, the anticorrosive properties of synthetic corrosion inhibitor has been studied. The present work assessed the synthesis and inhibition performance of 3-((dicyclohexyl amino)methyl)-5-(4-((2-hydroxybenzylidene) amino phenyl)-1, 3, 4-oxadiazole-2(3H)-thione (DHOT) on the corrosion of mild steel in 1 M HCl solution through weight loss and electrochemical measurements. DHOT was characterized using FTIR and 1H NMR measurements. Surface analysis was carried out using SEM and AFM. Chemical theoretical studies of DHOT were performed using density functional theory (DFT) calculations. Electrochemical measurement results showed that corrosion inhibition increased as inhibitor concentration increased, achieving a significant inhibition efficiency of 98.86% at optimum conditions. Polarization curves indicated that molecules of DHOT acted as a mixed-type inhibitor, and their adsorption process obeyed the Langmuir isotherm. Examination of corroded steel surface by SEM and AFM confirmed the adsorption of DHOT on metal surface. Chemical quantum calculations were used to determine the electronic properties of the DHOT and to explain inhibitor/metal surface interactions.
Metal corrosion is a destructive process for many industrial operations, including oil well acidi... more Metal corrosion is a destructive process for many industrial operations, including oil well acidizing and acid pickling. Therefore, numerous efforts made by many researchers to control the steel corrosion. In the present work, A (E)-4-(((4-(5-mercapto-1,3,4-oxadiazol-2-yl) phenyl) amino) methyl)-2-methoxyphenol (MOPM) has been synthesized and characterized as a new corrosion inhibitor for mild steel in 0.1 M hydrochloric acid. FTIR and 1 HNMR were used in the diagnosis of MOPM, while electrochemical polarization technique was employed to test the performance of inhibitor at various temperatures and inhibitor concentrations. Electrochemical studies showed that MOPM acts as a mixed-type inhibitor with a maximum inhibition efficiency of 93.2% at 30 ◦C and 0.5 M MOPM. Furthermore, the presence of MOPM increased the polarization resistance and depressed the corrosive action. The inhibitory action of MOPM over mild-steel surface was according to Langmuir adsorption isotherm. The calculated free energy of adsorption was − 20.663 kJ.mol− 1 that suggested the spontaneous physical adsorption mode. Value of activation energy was higher in the presence of MOPM, which indicated the formation of protective layer on the metal surface. Quantum chemical calculations that carried out to the chemical structure of MOPM provides a reasonable support to the experimental results.
International Journal of Environmental Science and Technology
The present work evaluated the potential of two types of wastes, fennel seed and garlic peels, to... more The present work evaluated the potential of two types of wastes, fennel seed and garlic peels, to uptake Congo red dye from aqueous solutions. Several techniques, like SEM, FTIR, and BET surface area, were utilized to characterize the two biomass materials used as biosorbents. The main effective parameters, namely initial concentrations (10-100 mg L −1), pH (4-9), contact time (0-60 min), and adsorbent/biosorbent dose (0.01-2.0 g), were examined. Equilibrium isotherms like the Langmuir, Freundlich, Temkin, and Harkins-Hasely models were modeled. The experimental data fit well with the Langmuir model for both GP and FSS. The maximum adsorption capacities obtained were 15.22 mg g −1 and 172.43 mg g −1 for GP and FSS, respectively. Two kinetic models, the pseudo first-order kinetic model and the pseudo-second-order kinetic model, were studied, and the data obtained from experimental work followed the pseudo-second-order kinetic model for both GP (R 2 = 0.9991) and FSS (R 2 = 0.9995), respectively. The final results indicated that fennel seed could be an alternative material and more efficient biosorbent for dye removal from contaminated water.
Iraqi Journal of Chemical and Petroleum Engineering
The corrosion behavior of bare and chemical conversion coated (through anodizing) aluminum ASA 60... more The corrosion behavior of bare and chemical conversion coated (through anodizing) aluminum ASA 606 I in stagnant chromic acid solutions . Solutions of 2, 6 & J O wt. % Cr03 at 45°C, have been investigated using polarization technique. The anodizing experiments were conducted under fixed conditions of 35 minute exposure time and 30 volt supplied voltage. The most important feature achieved was the great difference in behavior between the anodic polarization curves for bare and anodized aluminum in different concentrations of chromic acid solutions.
Corrosion inhibition is an extensive field of study, and its progression is gaining traction amon... more Corrosion inhibition is an extensive field of study, and its progression is gaining traction among researchers. This paper describes a study to synthesize and characterize a novel class of organic corrosion inhibitor called (3, 5dimethyl-1H-pyrazol-1-yl) (4-((4-chlorobenzy-lidene) amino) phenyl) methanone) (DPCM). The structure of DPCM was determined using FTIR, 1 H NMR and 13 C NMR techniques. The effectiveness of DPCM was tested on carbon steel in 1 M HCl using electrochemical and weight loss methods, and it was found that the inhibition efficiency increased with increasing temperature and DPCM concentration. The highest inhibition efficiency of 89.5% was achieved at 60 • C and 400 ppm DPCM. The inhibition action of DPCM molecules was achieved by blocking the metal surface by means of the adsorption of inhibitor molecules obeying the Langmuir adsorption isotherm. Adsorption-free energy indicates a spontaneous chemical adsorption process. The polarization test results clarified a mixed effect of DPCM on anodic and cathodic reactions. Electrochemical impedance spectroscopy indicated an increase in metal resistance in the presence of an inhibitor. The formation of a protective layer was confirmed by SEM and AFM analysis. Density functional theory (DFT) simulation has been used to determine the relationship between molecular configuration and their inhibition efficiencies.
1H-pyrazol-1-y1) (4-((3,4-dimethoxybenzylidene) amino) phenyl) methanone (DPMM) has been effectiv... more 1H-pyrazol-1-y1) (4-((3,4-dimethoxybenzylidene) amino) phenyl) methanone (DPMM) has been effectively synthesized and characterized. FTIR and NMR have been used to diagnose DPMM's functional groups and components. Electrochemical and weight loss methods were used to assess the inhibitor efficacy for low-carbon steel in 1 M HCl. By raising the temperature and DPMM concentrations, the inhibition efficiency improved. The inhibition efficiency approached 95.5 % at 400 ppm of DPMM and 60 • C. The efficiency of the inhibitor was ascribed to the formation of a protective mono-layer on the steel surface. The mechanism of the adsorption process was examined using the Langmuir adsorption isotherm, whereas the mechanism of inhibition was examined using theoretical quantum chemical simulations. The results revealed that the DPMM was the donor of electron, while the steel surface was an electron acceptor.
An aqueous extract of onion and garlic leaf extract (OGLE) blend was employed to retard low-carbo... more An aqueous extract of onion and garlic leaf extract (OGLE) blend was employed to retard low-carbon steel (LCS) corrosion in 1 M HCl for the first time. The corrosion inhibition ability of OGLE has been tested via weight loss and electrochemical techniques. Firstly, onion and garlic leaf extracts are separately tested at 30 • C using a Doehlert experimental design to find the optimum concentration of each extract. Secondly, a full-factorial design is used to evaluate the corrosion rate at different blend concentrations and temperatures. Experimental results revealed that the OGLE blend can be considered a good green inhibitor. At 300 ppm OGLE and 60 • C, the maximum blend corrosion inhibition efficacy was 96.65 %. The Langmuir adsorption isotherm demonstrates that OGLE adsorbed with negative heat of adsorption, suggesting a stable monolayer developed spontaneously on LCS. According to electrochemical experiments, when OGLE is present, corrosion current densities are greatly reduced.
1H-pyrazol-1-yl m (4-((4-hydroxybenzylidene) amino) phenyl) methanone (DPHM) has been effectively... more 1H-pyrazol-1-yl m (4-((4-hydroxybenzylidene) amino) phenyl) methanone (DPHM) has been effectively synthesized and characterized. The diagnosis of functional groups and constituents of DPHM has been conducted by FTIR, 1 H NMR, and 13 C NMR. The inhibitor efficacy for low-carbon steel in 1 M HCl was evaluated by using weight loss and electrochemical techniques. The inhibition efficiency was increased with increasing the temperature and DPHM concentrations. The inhibition efficiency approaches a maximum value of 89.5% at 400 ppm of DPHM and 60 • C. The efficiency of the inhibitor was attributed to the formation of a protective mono-layer on the steel surface. The Langmuir adsorption isotherm was used to inspect the adsorption process mechanism. Theoretical quantum chemical simulations were used to investigate the mechanism of inhibition. The results revealed that the DPHM was the donor of electron, while the steel surface was an electron acceptor. Mathematical and statistical modelling were used as powerful tool for data representation. Exponential model, with 0.992 correlation coefficient, was the most accurate one.
Electrocoagulation method is carried out to remove methyl orange from synthetic wastewater using ... more Electrocoagulation method is carried out to remove methyl orange from synthetic wastewater using iron-iron electrodes as anode and cathode. Effects of several experimental parameters treatment of methyl orange (MO) dye removal such as pH, initial concentration, current density and electrode ' s distance have been studied. The Taguchi method using L 16 orthogonal array experimental design was applied to optimize the experimental operating conditions that varied at four levels, initial pH (4-10), current density (1-4 mA/cm 2), electrode distance (0.5-1.5 cm), and initial concentration (25-100 mg/L), while the removal efficiency (%R) was considered as the response variable. The Taguchi method based on the average S/N graph method, in combination with analysis of variance (ANOVA), was applied to determine the significant parameters that affect the dye removal. The optimum conditions for removal of MO were determined to be initial concentration (25 mg/L) , electrode distance (0.5 cm) , pH (8), and current density (3 mA/cm 2). The Acidity pH factor represents the most significant factor affecting on removal of MO. The optimum response variables are 97.19 and 97.24% for observed and predicted values, respectively at 39.7575 S/N ratio. As a result, an excellent removal of methyl orange dye from wastewater was attained depending upon the best parametric conditions that obtained from Taguchi method.
In this paper, anodizing process of 5854 aluminum-magnesium alloy (5854Al-Mg) in oxalic acid (OXA... more In this paper, anodizing process of 5854 aluminum-magnesium alloy (5854Al-Mg) in oxalic acid (OXA) was investigated in the absence and presence of 5-sulfosalicylic acid (SSA). Electrochemical and surface morphological techniques were used to study the corrosion resistance and film characterizations. Furthermore, the influence of sealing time on corrosion rate was addressed. It was observed that the corrosion current density decreased with the addition of SSA and increasing with sealing time. Maximum coating efficiency was 90.72% in the presence of 0.09 M SSA at 50 min of sealing period. The open circuit potential (OCP) was shifted to a more positive direction indicating the formation of passive film. While, the values of polarization resistance (Rp) of aluminum alloy were higher in the presence of SSA. Scanning electron microscopy (SEM) showed that the addition of SSA improved the surface properties. The anodizing of 5854 Al alloy in the presence of SSA resulted in the formation of anodic films of higher hardness, less roughness, and high film thickness as compared with OXA alone. Reaction kinetics models were proposed. The best fitting was obtained with zero-order reaction kinetics. Half-life time was increased from 9.05 to 123.3 min in case of OXA/SSA anodizing process. In addition, four mathematical equations were suggested to represent the corrosion current density as a function of time. Power model was the most significant one as compared with linear, second order, and exponential models.
The behavior of the corrosion inhibition of mild steel in a brine produced water saturated with c... more The behavior of the corrosion inhibition of mild steel in a brine produced water saturated with carbon dioxide using 1, 3, 5, 7-tetraazaadamantane (TAA) as a heterocyclic organic inhibitor was investigated. Gravimetrical and electrochemical methods were used to determine corrosion rates and the experimental work were mathematically designed using Doehlert experimental design (DED). Corrosion rate was optimized as a function of TAA dosage, temperatures, and rotation rate. Maximum corrosion inhibition efficiency was 92% at optimum conditions. TAA was adsorbed chemically and spontaneously on metal surface according to Langmuir isotherm. These results were confirmed by scanning electron microscopy (SEM), optical microscopy, UV–Vis spectral, and FTIR techniques. Quantum chemical analysis was used as a theoretical tool. It was found that the protonated state of TAA was more efficient than the ground state.
Corrosion inhibition of C6.9 mild steel alloy in 2M H3PO4 solution by extracted aqueous of red po... more Corrosion inhibition of C6.9 mild steel alloy in 2M H3PO4 solution by extracted aqueous of red pomegranate peels (EARPP) as an green inhibitor have been investigated using Half – cell potentials measurments, electrochemical polarization technique measurments has been utilized to assess the corrosion parameters: Icorr., Ecorr., βc , βa and RP have been calculated using Extrapolation of cathodic and anodic Tafel plot and resistance of linear polarization technique. Experimental design of Taguchi procedure (EDTP) was applied for distribution of the polarization experiments conditions. The data obtained from the utilized two techniques are in great concurrence with each other. These investigations have demonstrated that EARPP is a very good "green", blended sort inhibitor. The inhibition procedure was ascribed to the formation of an adsorbed layer on the surface of metal that protects the metal against corrosive agents. The most important feature achieved was the polarization ...
The behavior of anodic porous alumina film formed on an aluminum surface by anodizing in chromic ... more The behavior of anodic porous alumina film formed on an aluminum surface by anodizing in chromic acid solutions was optimized using Box-Wilson experimental design. The film thickness was correlated as a function of temperature, acid concentration, applied voltage, and time. A mathematical model was suggested and optimized. Results of coating thickness indicate that both temperature and time play an important role in the anodizing process. The interaction effect of variables on the film thickness is less pronounced compared with the effect of the main variables. Optimum film thickness obtained during the anodizing process was 10.43 µm at the optimum value of temperature (45 °C) and time (68 min). The polarization measurement of anodized aluminum ASA 6061 in chromic acid shows a high corrosion resistance in the presence of coating. The results confirmed by using surface morphology investigations.
The inhibition of X80 steel corrosion by a 3-Methoxypropyl-amine (MOPA) as a new corrosion inhibi... more The inhibition of X80 steel corrosion by a 3-Methoxypropyl-amine (MOPA) as a new corrosion inhibitor in saline solution (3.5 wt% NaCl) was optimized at different temperatures, inhibitor concentrations, the rotation speed of the solution and pH. Mass loss and polarization measurements were used to evaluate the corrosion rate and other kinetics parameters. The inhibition performance of MOPA was optimized by factorial experimental designs. Optimum conditions for the minimum corrosion rate were 12.89°C, 8.63 g/l, 1097.69 rpm, pH 4.03. It was observed that MOPA follows the Langmuir adsorption isotherm with negative values of ΔG ads o , proposing a spontaneous and stable inhibition process. According to ΔG ads o values, a physical adsorption was suggested. The inhibitor efficiency increased with increasing the inhibitor concentration and pH of the solution. Moreover, increasing the solution temperature and rotation velocity had an adverse influence on inhibitor efficiency. Results of mass loss technique were agreed with the polarization one. Polarization diagrams revealed that the inhibitor affects as a mixed-type inhibitor. Surface morphology and FTIR spectrum studies were confirmed the effectiveness of the inhibitor. A theoretical quantum chemical simulation was a powerful tool for the optimization of the MOPA structure.
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Papers by Khalid Hamid