In this work, adsorption and thermodynamics study of the inhibition of corrosion of mild steel in H2SO4 medium using Vernonia amygdalina was carried out. The inhibitive and adsorptive properties of ethanol extract of ...In this work, adsorption and thermodynamics study of the inhibition of corrosion of mild steel in H2SO4 medium using Vernonia amygdalina was carried out. The inhibitive and adsorptive properties of ethanol extract of Vernonia amygdalina for the corrosion of mild steel in 0.2 M H2SO4 solutions was investigated using weight loss technique. The result has proved that that the extract is a good inhibitor of corrosion of mild steel in H2SO4. The inhibition efficiencies ranged from 23.37 to 38.59% and from 22.45 to 35.78% at 303 and 323K respectively. The inhibition efficiency of the extract decreased as temperature and time of immersion increased but increased with increase in concentration of extract. The adsorption of the inhibitor on surface of mild steel was found to be exothermic, spontaneous and consistent with the mechanism of physical adsorption as the value for heat of adsorption ranged from -2.12 to -4.87KJ mol–1. The adsorption data fitted well to Langmuir, Temkin, Frumkin and Flory-Huggins adsorption isotherms.展开更多
The effectiveness of Ibusa kaolinite as an adsorbent in removing pigments from palm oil has been investigated in this study. Ibusa kaolinite was prepared as an adsorbent by treating it with hydrochloric acid. The surf...The effectiveness of Ibusa kaolinite as an adsorbent in removing pigments from palm oil has been investigated in this study. Ibusa kaolinite was prepared as an adsorbent by treating it with hydrochloric acid. The surface area of the clay was found to increase with increase in acid dosage up to a maximum and then de-creased while its cation exchange capacity decreased with increase in acid dosage. The activated clay was used as an adsorbent for the removal of pigments from palm oil. The bleaching process was investigated by varying the clay dosage, acid concentration and temperature. The highest removal of pigments was recorded at 7 M HCl concentration, 4 g clay dosage and 100°C temperature, and about 97.4% pigments were removed in 80 minutes. Four isotherm models, three kinetic models, and the intra-particle diffusion model were applied to fit the experimental data. It was found that the equilibrium data were best represented by the Temkin isotherm model. The experimental data fitted well the pseudo-second-order kinetic model. Diffusion studies indicated that in-tra-particle diffusion is not the sole rate-controlling factor. The bleaching pro-cess was found to be spontaneous and endothermic, with increasing random-ness of adsorbed species.展开更多
文摘In this work, adsorption and thermodynamics study of the inhibition of corrosion of mild steel in H2SO4 medium using Vernonia amygdalina was carried out. The inhibitive and adsorptive properties of ethanol extract of Vernonia amygdalina for the corrosion of mild steel in 0.2 M H2SO4 solutions was investigated using weight loss technique. The result has proved that that the extract is a good inhibitor of corrosion of mild steel in H2SO4. The inhibition efficiencies ranged from 23.37 to 38.59% and from 22.45 to 35.78% at 303 and 323K respectively. The inhibition efficiency of the extract decreased as temperature and time of immersion increased but increased with increase in concentration of extract. The adsorption of the inhibitor on surface of mild steel was found to be exothermic, spontaneous and consistent with the mechanism of physical adsorption as the value for heat of adsorption ranged from -2.12 to -4.87KJ mol–1. The adsorption data fitted well to Langmuir, Temkin, Frumkin and Flory-Huggins adsorption isotherms.
文摘The effectiveness of Ibusa kaolinite as an adsorbent in removing pigments from palm oil has been investigated in this study. Ibusa kaolinite was prepared as an adsorbent by treating it with hydrochloric acid. The surface area of the clay was found to increase with increase in acid dosage up to a maximum and then de-creased while its cation exchange capacity decreased with increase in acid dosage. The activated clay was used as an adsorbent for the removal of pigments from palm oil. The bleaching process was investigated by varying the clay dosage, acid concentration and temperature. The highest removal of pigments was recorded at 7 M HCl concentration, 4 g clay dosage and 100°C temperature, and about 97.4% pigments were removed in 80 minutes. Four isotherm models, three kinetic models, and the intra-particle diffusion model were applied to fit the experimental data. It was found that the equilibrium data were best represented by the Temkin isotherm model. The experimental data fitted well the pseudo-second-order kinetic model. Diffusion studies indicated that in-tra-particle diffusion is not the sole rate-controlling factor. The bleaching pro-cess was found to be spontaneous and endothermic, with increasing random-ness of adsorbed species.
