Browsing by Author "Ogunleye, O.O"
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Item ADSORPTION OF CONGO RED DYE ONTO COCONUT SHELL BASED NaOH ACTIVATED CARBON: KINETICS, THERMODYNAMICS AND OPTIMISATION STUDIES(Published by College of Engineering and Technology. Michael Okpara University of Agriculture. Umudike, 2017-06) Eletta, O.A; Ogunleye, O.O; Morakinyo, A.FCoconut Shell (CS) was carbonised, activated with NaOH and used to adsorb Congo Red (CR) dye from its aqueous solution. Proximate and ultimate analyses, Fourier Transform Infra-red (FTIR) and Scanning Electron Microscope (SEM) were used to characterize both the raw and the Coconut Shell Activated Carbon (CSAC) while UV spectrophotometer was used to monitor the CR dye concentration. Batch adsorption experiments were carried out using 100 ml each of 50 mg/l to 250 mg/l CR dye solution at different contact times, and temperature. To establish optimum adsorption conditions, Central Composite Design (CCD) in Response Surface Methodology (RSM) was employed using the initial dye concentration, contact time and temperature as variables at a fixed pH of 3 and 0.2 g/100ml of adsorbent. Adsorption capacity of 122.00 mg/g was obtained with CR concentration, contact time and temperature of 250 mg/l, 180 min and 30oC, respectively. Pseudo first order kinetic model best fitted the experiment. The coefficients of determination of Langmuir, Freundlich and Temkin isotherms were 0.978, 0.974 and 0.863, respectively, with Langmuir isotherm giving a better fit for the adsorption. The maximum monolayer adsorption capacity from Langmuir isotherm was 121.56 mg/g at pH 3 and a temperature of 30oC.Item Adsorption of cyanide from aqueous solution using calcinated eggshell: equilibrium and optimisation studies(Elsevier, 2016) Eletta, O.A; Ajayi, O.A; Ogunleye, O.O; Akpan, I.CEggshells were calcined and used to adsorb cyanide from its aqueous solution. X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier Transform Infra-red (FTIR) and Scanning Electron Microscope (SEM) were used to characterize both raw and calcined eggshell (CE) while UV spectrophotometer was used to monitor the cyanide concentration. The XRD and FTIR showed the conversion of CaCO3 to CaO. Batch adsorption experiments were carried out using 10 ml each of 0.01 mol/L to 0.05 mol/L cyanide solutions at different contact times, and adsorbent dosages. To establish optimum adsorption conditions, Central Composite Design (CCD) in Response Surface Methodology (RSM) was employed using the time, concentration and adsorbent dosages as variables at a fixed pH of 7. Adsorption efficiency of 84.53% was obtained with 0.01 mol/L, 8.98 g of calcined eggshell at 26.58 min contact time using RSM. Pseudo second order kinetic model best fitted the experiment. The coefficients of determination of Langmuir and Freundlich isotherms were 0.988 and 0.650 respectively, with Langmuir isotherm giving a better fit for the adsorption. The maximum monolayer adsorption capacity from Langmuir isotherm was 3.27 mg/g at pH 7 and a temperature of 30 °CItem Gravimetric and quantitative surface morphological studies of Mangiferaindica peel extract as a corrosion inhibitor for mild steel in 1 M HCl solution(Curtin University, 2018) Ogunleye, O.O; Eletta, O.A; Arinkoola, A.o; Agbede, O.OMangifera indica peel extract was evaluated as a corrosion inhibitor for mild steel in 1 M HCl using gravimetric and depth of attack techniques. The extract was characterized using gas chromatography – mass spectrometry and the solution film solution by Fourier transform infrared spectroscopy. Scanning electron microscopy, arithmetic mean deviation of the surface profile (Ra), and the maximum height of irregularities (Rz) were used to characterize mild steel coupon surfaces. Effect of temperature, concentration, and time on the corrosion rate of the coupon with and without M. indica peel extract were evaluated. The adsorption of this inhibitor was found to obey the Freundlich model, and thermodynamic parameters were ∆G_ads^o (-8.39 kJ/mol),∆H_a^o (16.21 kJ/mol),and ∆S_a^o (-70.41 kJ/mol). Maximum inhibition efficiencies were 95.75% and 95.76% using weight loss and depth of attack methods, respectively.Item Identification and Characterisation of Major Hydrocarbons in Thermally Degraded Low Density Polyethylene Films(University of Port Harcourt, 2017-10) Eletta, O.A; Ajayi, O.A; Ogunleye, O.O; Tijani, I.A; Adeniyi, A.G; Agbana, A.SThe vast application of Low Density Polyethylene (LDPE) in packaging, greenhouses, homes etc has led to its huge accumulation as a municipal solid waste with monumental health, economic and environmental consequences. Since these are non-biodegradable and their photodegradation occurs only over a very long period, their economic conversion to energy products through pyrolysis is the thrust of this study. LDPE sample collected from the University of Ilorin Community was thermally degraded in a pyrolyser at temperatures ranging from 203 – 400 oC. The products of pyrolysis were in three (3) states of matter and both the liquid and solid products were analysed using FTIR to determine the functional groups and GC- MS for the hydrocarbons present in the products. For the GC-MS analysis, the peaks that had 90% above quality when compared with the compounds in the installed NIST11 library were reported. There were alkanes, alkenes, halogenated alkanes, and very few aromatics in the liquid product and, the hydrocarbons were observed to range between C10 - C27. The FTIR and GC-MS results show the potential of the oil obtained as renewable source of energy while that for residue shows its inherent energy content. The liquid product was refluxed over molecular sieve catalyst (US 2882244A) and the calorific value was found to increase from 13,974 kJ/kg to 15,815.52 kJ/kg and this is found to be comparable to the range for lignite and dry wood.Item MODELLNG AND OPTIMISATION OF OIL EXTRACTION FROM LOOFAH (Luffa cylindrica) SEEDS USING BINARY SOLVENT MIXTURE(Turkish Chemical Society, 2019) Eletta, O.A.A; Adewoye, L.T; Mustapha, S.I; Adeniyi, A.G; Ogunleye, O.OToxicity and safety concern coupled with the recent increase in its price has necessitated the need for finding alternative solvents to n-hexane. In this study, the effect of binary solvent (ethanol/n-hexane) composition at various extraction temperatures and times on the oil yield was investigated using response surface methodology (RSM). Artificial neural network (ANN) was used as a modelling tool for predicting the oil yield and the performance of both ANN and RSM models was compared. The optimum oil yield (27.67%) was obtained at extraction temperature (40 °C), extraction time (151.9 min) and binary solvent composition (98% ethanol /2% n-hexane). The predicted oil yield values from ANN model was more accurate than that of RSM when compared with experimental values. The fatty acid profile revealed that the refining process promoted saturation of the extracted oil with 67.75% of palmitic acid present in refined loofah seed oil (RLSO). This study demonstrated the feasibility of using a binary mixture of ethanol and n-hexane as a suitable replacement to the commonly used toxic n-hexane solvent for the extraction of oil from loofah seeds.