scholarly journals A thermometric study on the kinetics of the acid dissolution of aluminium in the presence of Napoleonaea imperialis seeds extract and iodide ions

2018 ◽  
Vol 29 (2) ◽  
pp. 103-109 ◽  
Author(s):  
Habibat Faith Chahul ◽  
Gloria Ihuoma Ndukwe ◽  
David Ogwu Ogwu
Keyword(s):  
Free Energy ◽  
Inhibition Efficiency ◽  
Adsorption Process ◽  
Langmuir Adsorption Isotherm ◽  
Seed Extract ◽  
Considerable Extent ◽  
Acid Dissolution ◽  
Iodide Ions ◽  
Langmuir Adsorption ◽  
Kinetics Of

Abstract The dissolution of aluminum alloy AA 1060 in 0.5 M and 1.0 M HCl was investigated using thermometric measurements. The reaction number of the aluminum coupons varied linearly with the concentration of the acid. Addition of Napoleonaea imperialis seed extract to the dissolving aluminium coupons lowered the reaction number in both concentrations of HCl by inhibiting the dissolution process. The inhibition efficiency of Napoleonaea imperialis seed extract was enhanced to a considerable extent in the presence of iodide ions with the synergistic parameter S > 1. The adsorption of Napoleonaea imperialis extract on the aluminium surface best aligned with the Langmuir adsorption isotherm model. The values of the free energy, ΔGadsfor the adsorption process revealed the process to be spontaneous and physisorptive.

scholarly journals Inhibition of Aluminium Corrosion in Hydrochloric Acid Using Nizoral and the Effect of Iodide Ion Addition

2010 ◽  
Vol 7 (3) ◽  
pp. 837-843 ◽  
Author(s):  
I. B. Obot ◽  
N. O. Obi-Egbedi
Keyword(s):  
Free Energy ◽  
Hydrochloric Acid ◽  
Adsorption Isotherm ◽  
Aluminium Alloy ◽  
Acidic Medium ◽  
Inhibition Efficiency ◽  
Adsorption Process ◽  
Considerable Extent ◽  
Inhibitor Concentration ◽  
Hcl Solution

The effect of nizoral (NZR) on the corrosion inhibition of aluminium alloy AA 1060 in 2 M HCl solution was investigated using the mylius thermometric technique. Results of the study revealed that nizoral acts as corrosion inhibitor for aluminium in the acidic medium. In general, at constant acid concentration, the inhibition efficiency increases with increase in the inhibitor concentration. The addition of KI to the inhibitor enhanced the inhibition efficiency to a considerable extent. The adsorption of nizoral onto the aluminium surface was found to obey the Fruendlich adsorption isotherm. The value of the free energy for the adsorption process shows that the process is spontaneous.

scholarly journals Fatty Amidine as Copper Corrosion Inhibitor

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Zainal Alim Mas’ud ◽  
Noviyan Darmawan ◽  
Januari Dawolo ◽  
Yusuf Bramastya Apriliyanto
Keyword(s):  
Corrosion Inhibitor ◽  
Corrosion Inhibitors ◽  
Inhibition Efficiency ◽  
Adsorption Process ◽  
Copper Surface ◽  
Langmuir Adsorption Isotherm ◽  
Copper Corrosion ◽  
Langmuir Adsorption ◽  
New Type ◽  
Corrosion Inhibition Efficiency

The development of green and sustainable corrosion inhibitors for copper in a corrosive marine environment is highly desired. Herein, we studied the fatty acid-based amidine as the new type of renewable corrosion inhibitor. Stearamidine salt was used as a model inhibitor, and it was synthesized through stearonitrile intermediate with an excellent isolated yield of 88%. We used electrochemical (potentiodynamic polarization) and morphological (scanning electron microscopy) measurements to assess the corrosion inhibition efficiency of stearamidine in 3.0 wt.% NaCl at 300 K. We show that, in such a condition, the optimum inhibition efficiency of 96% was achieved using only 0.2 mM stearamidine. The results suggested the fatty amidine is a promising corrosion inhibitor for copper that is suitable in the saltwater ecosystem. The thermodynamic parameters of the interaction between the stearamidine and the copper surface were determined, and the result suggests that the adsorption process occurred accordingly with the Langmuir adsorption isotherm and involved both physisorption and chemisorption.

Heavy meatals removal by a promising locally available aquatic plant, Najas graminea Del., in Taiwan

1999 ◽  
Vol 39 (10-11) ◽  
pp. 177-181 ◽  
Author(s):  
Chon-Lin Lee ◽  
Tsen C. Wang ◽  
Ching-Ku Lin ◽  
Hin-Kiu Mok
Keyword(s):  
Aquatic Plant ◽  
Adsorption Process ◽  
Lead Concentration ◽  
Langmuir Adsorption Isotherm ◽  
Competitive Effect ◽  
Langmuir Adsorption ◽  
Kinetics Of ◽  
Copper Lead ◽  
Plating Wastewater ◽  
Nickel Adsorption

This study uses an aquatic plant, Najas graminea Del., to treat man-made wastewater containing single and/or binary components of copper, lead, cadmium and nickel. Adsorption experiments demonstrate that the adsorption process correspond to the Lagergren kinetic model with the rate constant close to 0.01 min−1; meanwhile, the equilibrium results corresponds to the Langmuir adsorption isotherm. Notably, the rate constants of metals are not significantly different between each other. Competitive effect on the adsorption kinetics of cadmium is insignificant with the background solute (lead) concentration up to 10 mg/l; while significant deviation observed with concentration of lead reached 100 mg/l. In addition, the maximum adsorption density of cadmium is reduced by around 50% in the presence of 100 mg/l of lead. A simulated copper plating wastewater is also treated by Najas graminea Del. to demonstrate its efficiency in removing metals from wastewater with multi-cations/anions.

scholarly journals Inhibition of Pipeline Steel Corrosion in 0.5 M H2SO4 Using Cotyledon of Chrysophyllum Albidum

2020 ◽  
Vol 24 (4) ◽  
pp. 691-697
Author(s):  
E.P. Othaki ◽  
N.C. Ngobiri
Keyword(s):  
Corrosion Inhibitors ◽  
Inhibition Efficiency ◽  
Adsorption Process ◽  
Pipeline Steel ◽  
Steel Corrosion ◽  
Langmuir Adsorption ◽  
Extract Concentration ◽  
Ir Studies ◽  
Ft Ir ◽  
As Adsorption

The corrosion inhibition characteristics of Chrysophyllum albidum cotyledon extract was studied as a green and sustainable corrosion inhibitors for pipeline steel in acidic environment attemperatures, 303,313 and 323K using gravimetric technique.The results obtained showed that the inhibition efficiency increased with increase in extract concentration but decrease with increase in temperature. The extract attained an inhibition efficiency of 94 % with 5 g/L at 303 K and 52.2 % with 1 g/L at 333K. Also increase in concentration of the extract lead to increase in activation energydepicting an exothermic process.Fourier transform infrared spectroscopy (FT-IR) studies showed the mode of inhibition as adsorption of phytochemicals from the extract on pipeline steel surface. Langmuir adsorption isotherm best fitted into the adsorption process which is spontaneous and physical. Keywords: Chrysophyllum albidum, Pipeline steel, Inhibition, Adsorption.

INVESTIGATION OF ADSORPTION AND INHIBITIVE EFFECT OF CALIXARENE DERIVATIVE NEWLY SYNTHESIZED TOWARDS C38 STEEL IN MOLAR HCl

2009 ◽  
Vol 16 (03) ◽  
pp. 401-406 ◽  
Author(s):  
R. SOUANE ◽  
M. KADDOURI ◽  
M. BOUKLAH ◽  
N. CHERIAA ◽  
B. HAMMOUTI ◽  
...  
Keyword(s):  
Weight Loss ◽  
Inhibition Efficiency ◽  
Langmuir Adsorption Isotherm ◽  
Enthalpy Of Adsorption ◽  
Langmuir Adsorption ◽  
Corrosion Phenomenon ◽  
Calixarene Derivative ◽  
Current Densities ◽  
C38 Steel ◽  
Mixed Type Inhibitor

The focus of this study is to synthesize a new calixarene derivative namely calix[6]arene (C21) and to test its performance as corrosion inhibitor of C38 steel in molar HCl at 308 K. Polarization and weight loss measurements were used. Weight loss tests show that C21 retards until to stop corrosion phenomenon at 5 × 10-5 M . C21 is an excellent inhibitor and its inhibition efficiency increases with its concentration to reach 100% since 5 × 10-5 M . Polarization curves revealed that C21 affects both cathodic and anodic domains by decreasing current densities and then it may be classified as a mixed type inhibitor. The calixarene tested is adsorbed on the surface according to the Langmuir adsorption isotherm. Free enthalpy of adsorption reveals that C21 acts from chemisorption onto the steel surface.

Effect of Andrographis paniculata (Burm.f.) Wall.ex Nees extract on corrosion of low C-steel in 0.1 M HCl

2016 ◽  
Vol 63 (6) ◽  
pp. 470-476 ◽  
Author(s):  
Pawin Wongkhamprai ◽  
Manthana Jariyaboon
Keyword(s):  
Inhibition Efficiency ◽  
Adsorption Process ◽  
Electrochemical Impedance ◽  
Andrographis Paniculata ◽  
Low Carbon ◽  
Content Type ◽  
Langmuir Adsorption ◽  
Green Corrosion Inhibitor ◽  
Corrosion Inhibition Efficiency ◽  
Environmentally Friendly Method

Purpose The aim of this work was to investigate how Andrographis paniculata (Burm.f.) Wall.ex Nees extract affected the corrosion of low-carbon (C) steel in 0.1M HCl. Design/methodology/approach The Andrographis paniculata (Burm.f.) Wall.ex Nees was extracted into distilled water at 70°C for 1 h. The corrosion inhibition efficiency of the extract was determined in 0.1M HCl using weight loss measurements, potentiodynamic polarization and electrochemical impedance spectroscopy. The effects of extract concentrations and of temperature were investigated. Findings The Andrographis paniculata (Burm.f.) Wall.ex Nees extract could inhibit the corrosion process of low-C steel in 0.1M HCl. With the extract concentration of 1 g/l, an inhibition efficiency of 96.3 per cent was obtained. The extract acted as an anodic inhibitor. The adsorption process of the extract was physisorption and it followed the Langmuir adsorption isotherm. Originality/value This paper revealed that Andrographis paniculata (Burm.f.) Wall.ex Nees cultivated in Thailand, which was extracted using a simple and environmentally friendly method, could act as a very good green corrosion inhibitor for low-C steel in 0.1M HCl solution.

Kinetic Process of Purple Cabbage Pigment on Macro Porous Absorbent Resin

2011 ◽  
Vol 236-238 ◽  
pp. 1987-1990
Author(s):  
Jian Hua Yi ◽  
Zhen Bao Zhu ◽  
Yuan Fang Wu
Keyword(s):  
Free Energy ◽  
Gibbs Free Energy ◽  
Adsorption Kinetics ◽  
Temperature Increase ◽  
Adsorption Process ◽  
Adsorbent Resin ◽  
Temperature Range ◽  
Porous Adsorbent ◽  
Kinetics Of ◽  
Langmuir And Freundlich Models

The adsorption kinetics of purple cabbage pigment (PCP) on LSA-21 macro porous adsorbent resin were studied at different adsorbent resin concentrations (1, 2, 4, 8 g adsorbent resin per liter of purple cabbage extraction solution) for the temperature range of 20~50°C. The results showed that the adsorption of PCP in purple cabbage extraction solution onto LSA-21 macro porous adsorbent resin is highly in agreement with both Langmuir and Freundlich models. Heat of adsorption (ΔH) value of 11.976 kJ/mol indicates the endothermic adsorption process. A decrease of Gibbs free energy (ΔG) with temperature increase also indicates the spontaneous nature of the process.

scholarly journals Surface Protection of Steel by Adsorption of Milletia Pinnata Extract

2016 ◽  
Vol 13 (2) ◽  
pp. 101-105
Author(s):  
Monikandon Sukumaran ◽  
Kesavan Devarayan
Keyword(s):  
Weight Loss ◽  
Steel Surface ◽  
Inhibition Efficiency ◽  
Physical Adsorption ◽  
Ethanolic Extract ◽  
Steel Corrosion ◽  
Langmuir Adsorption Isotherm ◽  
Surface Protection ◽  
Langmuir Adsorption ◽  
Thermochemical Parameters

Steel corrosion inhibition in acidic and alkaline medium by ethanolic extract of Milletia pinnata is described in this study. The inhibitive behavior of the inhibitor is evaluated by weight loss measurements, adsorption isotherms, and thermochemical parameters. The inhibitor exhibited a maximum of 87% and 90.5% inhibition efficiency against steel corrosion in 0.5 M NaOH and 1.0 M H2SO4, respectively. The weight loss linearly fit to Langmuir adsorption isotherm with correlation coefficient value close to unity. The thermochemical parameters indicated for predominant physical adsorption of the inhibitor molecules on the steel surface.

scholarly journals Malachite Green Removal by Zn/Al-citrate LDHs in Aqueous Solution

2020 ◽  
Vol 5 (2) ◽  
pp. 59
Author(s):  
Nurlisa Hidayati ◽  
Risfidian Mohadi ◽  
Elfita Elfita ◽  
Aldes Lesbani
Keyword(s):  
Aqueous Solution ◽  
Malachite Green ◽  
Adsorption Process ◽  
Langmuir Adsorption Isotherm ◽  
Precipitation Method ◽  
Chemical Adsorption ◽  
Langmuir Adsorption ◽  
Batch System ◽  
Isotherm Adsorption ◽  
Co Precipitation

Zn/Al-citrate LDHs was synthesized using co precipitation method at basic condition and the material were applied as adsorbent of malachite green (MG) dye in aqueous medium using batch system. Adsorption of MG onto Zn/Al-citrate was investigated through kinetic, isotherm adsorption and thermodynamic studies. Kinetic model was fitted PSO than PFO for MG adsorption. The rate of adsorption 𝑘2 for Zn/Al LDHs was 0.000692 g.mg−1 min−1 and 0.000371 g for Zn/Al-citrate LDHs.mg−1 min−1. Adsorption of malachite green onto Zn/Al LDHs and Zn/Al citrate LDHs was investigated and following Langmuir adsorption isotherm model shows chemical adsorption process. The adsorption capacity maximum of Zn/Al-citrate is 333 mg/g from Zn/Al LDHs is only 111 mg/g. Thermodynamic parameters of Zn/Al-citrate confirmed adsorption process was endothermic and spontaneous.

scholarly journals 4-{[4-(Dimethylamino)benzylidene]amino}-5-methyl-4H-1,2,4-triazole-3-thiol as Corrosion Inhibitor for 316 Stainless Steel in 2.5 M Sulphuric Acid: An Experimental and Theoretical Investigation

2020 ◽  
Vol 32 (5) ◽  
pp. 1015-1025
Author(s):  
N. Shet ◽  
R. Nazareth ◽  
P. Krishna Murthy ◽  
P.A. Suchetan
Keyword(s):  
Stainless Steel ◽  
Inhibition Efficiency ◽  
Theoretical Calculations ◽  
Dft Method ◽  
Langmuir Adsorption Isotherm ◽  
Basis Set ◽  
X Ray ◽  
Langmuir Adsorption ◽  
316 Stainless Steel ◽  
Stainless Steel 316

The corrosion inhibition competence of 4-{[4-(dimethylamino)benzylidene]amino}-5-methyl-4H-1,2,4-triazole-3-thiol (DBTT) on 316 stainless steel (316 SS) in 2.5 M H2SO4 was studied using various electrochemical as well as weight-loss measurements. The alloy surface was examined by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Concentration effect on inhibition efficiency was investigated by varying concentration from 5 to 2000 ppm in the temperature range 30-60 °C. Results indicated mixed-type inhibitory action of DBTT. The efficiency increased with the raise in concentration of DBTT and temperature, reaching a highest of 92.4 % at 60 °C. Langmuir adsorption isotherm is obeyed. Calculation of different thermodynamic factors suggests that the adsorption is via both physisorption and chemisorption. In addition to these, several global reactivity parameters were calculated using DFT method at B3LYP/6-311++(d,p) basis set. Theoretical calculations are in good concurrence with the experimental results.

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