Papers by Ezekiel Odebunmi
Faculty of Engineering, University of Maiduguri, Maiduguri, Nigeria., Apr 1, 2017
Ethiopian Journal of Environmental Studies and Management, 2014
This study was carried out to investigate the portability of drinking water sources available to ... more This study was carried out to investigate the portability of drinking water sources available to people in parts of Osun State, Nigeria, especially with respect to trace metal levels. The trace metal contents were determined over a period of six months covering both the rainy and dry seasons. Tap, well, stream and borehole water from five towns (Osogbo, Iwo, Ejigbo, Ile-Ife and Ilesha) in Osun State were analysed using Atomic Absorption Spectrophotometer. The concentrations of the metals analyzed range (µg/mL) as follows: Fe (0.18-0.30), Mn (0.33-0.37), Zn (0.11-0.14), Cu (0.05-1.0), Pb (0.01-0.03), Hg (Nd-0.03), As (Nd-0.03), Cd (Nd-0.04), Cr (0.02-0.05), and Ni (0.02-0.05) while the mean levels (ug/mL) were of the order: Hg (0.01) < Pb (0.02) = As (0.02) = Cd (0.02) < Ni (0.03) < Cr (0.04) < Cu (0.08) < Zn (0.13) < Fe (0.25) < Mn (0.36). The results indicated a significant correlation in the metal contents of the water samples from the various locations as well as the various water sources. The trace metals contents (Fe, Mn, Zn, Cu, Cr and Ni) were below or equal to the limits set by WHO for drinking and domestic water while the toxic metals (Pb, Hg, As and Cd), recorded values higher than the safe limits set by WHO hence, the water sources are capable of constituting serious health hazards.
Bulletin of the Chemical Society of Ethiopia, 2012
Activated carbons were prepared from fruit pericarp and seed coat of Jatropha curcas using KOH an... more Activated carbons were prepared from fruit pericarp and seed coat of Jatropha curcas using KOH and NaCl as activating agents leading to the production of four samples of activated carbons JPS, JPP, JCS and JCP. The adsorption capacity based on adsorption of methylene blue was determined for each sample. A further study of adsorptive properties of the most efficient activated carbon (JPS) was made by contacting it with standard solutions of methylene blue, acetic acid and potassium permanganate. The effects of mass of active carbon used, initial concentration of the solute and the pH of the solution on adsorption performance were investigated. Ash content and percentage fixed carbon were determined for two of the activated carbons (JPS and JCS) with the highest adsorptive capacity. Equilibrium study on adsorption was carried out and the adsorption data were analyzed using the Langmuir isotherm. The results obtained indicate that activated carbons from the fruit pericarp and the seed coat of J. curcas can be used as high performance adsorbents with the fruit pericarp activated carbon showing the higher adsorption capacity. The adsorption data fitted well to the Langmuir model and adsorptive area of 824-910 m 2 /g was obtained for the activated carbon.
Journal of the Iranian Chemical Society, 2008
The kinetics of oxidation of glucose, galactose, fructose, maltose and sucrose by alkaline perman... more The kinetics of oxidation of glucose, galactose, fructose, maltose and sucrose by alkaline permanganate anion has been studied. The reactions studied spectrophotometrically over a wide range of experimental conditions show that the rate of the reactions is enhanced by increase in pH, ionic strength, and temperature as well as the reactant concentrations. The mechanism has been proposed to proceed via the formation of enediol intermediate complexes and the order of reactivities of the sugars is fructose > glucose § galactose > maltose > sucrose. The activation parameters were evaluated and lend further support to the proposed mechanism.
Petroleum Science and Technology, 2014
ABSTRACT Nigeria light, medium, and heavy crude oils were categorized based on the ratio of vanad... more ABSTRACT Nigeria light, medium, and heavy crude oils were categorized based on the ratio of vanadium-to-nickel (V/Ni) and the ratio of phenanthrene-to-dibenzothiophene (PHEN/DBT) derivatives. V/Ni ratio of 0.47, 1.36, and 2.77 were observed for light, medium, and heavy crude oils, respectively, while the PHEN/DBT ratio was observed to be 8.35, 4.33, and 1.09 for the light, medium, and heavy crude oils, respectively. From the results obtained, light crude oil was suggested to originate from marine organic matter while the heavy oil originates from the terrestrial organic matter.
International Journal of Physical Sciences, Sep 30, 2009
The kinetics of carbonate sugars and sugar alcohols by potassium permanganate in oxidation hydrog... more The kinetics of carbonate sugars and sugar alcohols by potassium permanganate in oxidation hydrogen / NaOH buffer have been investigated spectrophotometrically under pseudo-first order conditions and over a wide range of experimental conditions. Each reaction is first order with respect to the substrate and oxidant. The kinetic data for the oxidation by alkaline KMnO 4 solution reveal that pseudo-first order rate constants increased as the pH, Ionics strenghts, temperature as well as the KMnO 4 concentration increased. The rate constant also increases with increase in sugar concentration with the exception of sorbitol which its rate constant decreased with increase in sugar concentration. The mechanisms were found to proceed through the formation of enediol intermediate complex. The order of reactivities of sugar and sugar alcohols was sucrose > maltose > sorbitol > glucose> mannitol >fructose. The Arrhenius activation energy and other dynamic activation parameter are reported.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Ife Journal of Science, 2021
In this paper, Fe2+ , Pb2+ , Zn2+ and Cr6+ ions removal from contaminated water with natural Nige... more In this paper, Fe2+ , Pb2+ , Zn2+ and Cr6+ ions removal from contaminated water with natural Nigerian kaolinite clay (AK-clay), and that removed with kaolinite clay modified with either ammonium oxalate (AK-AO) or sodium hydroxide (AK-S) were presented. The clay was characterized using X-Ray Diffractometry (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Brunanuer-EmmettTeller (BET) method. The parameters investigated include pH, adsorbent particle size, shaking speed, metal ion concentration and temperature. The optimum conditions were applied to the modified samples. Design-expert software was used to design the experimental conditions using Response Surface Methodology (RSM). The mineralogical characterization showed the purified 63 µm fraction of the clay as kaolin. Analysis of Variance shows the adsorption of the metal ions was statistically significant with p-valves > 0.0001 at 95 % confidence limit. Pseudo second-order kinetic m...
Journal Of Chemical Society Of Nigeria, 2018
Nigeria is blessed with abundant kaolin clay and solid mineral deposits scattered in various part... more Nigeria is blessed with abundant kaolin clay and solid mineral deposits scattered in various parts of the country, yet the country solely depends on imported zeolite as commercial adsorbent for wastewater treatment, catalyst for the petroleum industry and other applications. This work describes the development of a process to produce zeolite from clay mineral.The beneficiated kaolin clay was converted to metakaolin at 600oC, and then leached with sulphuric acid to achieve the required silica-alumina ratio for zeolite synthesis. An alkaline fusion stage was then carried-out to transform the metakaolin into zeolite. Identification of the crystalline phase by X-Ray Diffraction analysis showed that it consists of both zeolite X and Y. Infrared spectra analysis confirmed the presence of zeolite framework structure. Transmission electron microscopy, surface area and pore volume of the synthesized zeolite were examined and the results from all the analysis confirmed that zeolite can be pro...
A novel nano-scaled zerovalent iron (nZVI) is an effective adsorbent for scavenging inorganic and... more A novel nano-scaled zerovalent iron (nZVI) is an effective adsorbent for scavenging inorganic and organic toxicants. nZVI was synthesized in a single pot system using bottom-up approach and were characterized by BET, SEM, EDX and FTIR. In this study, sorption of Cu2+ onto nZVI was carried out vis-a-vis the investigation of physicochemical parameters (initial metal ion concentration, pH, temperature, adsorbent dose) at 298 K. The sorption data obtained at optimum conditions were subjected to six different isotherm models (Langmuir, Freundlich, Tempkin, Dubinin-Raduskevich (DRK), Halsey and Harkin-Jura). However, the equilibrium sorption data were best described by both Langmuir and Temkin isotherm models with Langmuir maximum monolayer coverage (Qmax) of 40.816 mg/g and regression correlation value (R2 > 0.96) supporting a chemisorption mechanism. Pseudo first-and second-order, Elovich, fractional power and intra-particle diffusion models were applied to the adsorption data in ord...
Journal Of Chemical Society Of Nigeria, 2019
A new heterobimetallic ruthenium(II) complex with general formula [Ru(NCCH3)2(P(OMe)2Ph)2- (dppf)... more A new heterobimetallic ruthenium(II) complex with general formula [Ru(NCCH3)2(P(OMe)2Ph)2- (dppf)][BF4]2. {NCCH3 = acetonitrile P(OMe)2Ph = dimethylphenylphosphonite, dppf = 1,1’-bis-{diphenylphosphino}ferrocene} was synthesized from a one pot reaction of [Ru(COD)-(NCCH3)4][BF4]2, dimethylphenylphosphonite and 1,1’-bis{diphenylphosphino}ferroc-ene in dichloromethane under continuous stirring. The complex was characterized by NMR (31P{1H}, 1H and 13C), vibrational spectroscopy (FTIR) and elemental analysis. Catalytic performance of the complex in the transfer hydrogenation of cyclohexanone was investigated. An 80% conversion was achieved at a substrate to catalyst ratio of 1250 with 98% selectivity. Keywords: Heterobimetallic ruthenium, transfer hydrogenation, cyclohexanone, 1,1’-bis{diphenylphosphino}ferrocene, dimethylphenylphosphonite.
Samples of light, medium and heavy Nigerian crude oils and petroleum products including diesel oi... more Samples of light, medium and heavy Nigerian crude oils and petroleum products including diesel oil, engine oil (SAE 40) and gasoline (PMS) have been separated into four fractions of saturates, monoaromatics, diaromatics and polyaromatics by elution liquid chromatography. The fractions obtained were analysed using IR and UV-visible spectrophotometry. The infrared data confirmed the presence of methyl and methylene groups in the saturate fractions of the crude oils and petroleum products. The C=C stretching vibrations and C---H out of plane bending vibration of aromatics were also found in the mono-, di- and polyaromatics fractions. The characteristic UV spectra of alkyl benzenes and naphthalenes were observed in the monoaromatic and diaromatic fractions, respectively. The spectra of the polyaromatic fractions indicate the presence of anthracenes and phenanthrenes.
Journal of Physics: Conference Series, 2019
Bentonite clay supported nanoscale zerovalent iron (BC-nZVI) composite was successfully prepared.... more Bentonite clay supported nanoscale zerovalent iron (BC-nZVI) composite was successfully prepared. BC-nZVI was characterized by physicochemical and spectroscopic techniques. Surface area as determined by sear’s method is 291.2 cm2. Adsorption operational parameters were investigated in a batch technique. At 500 mg/L initial concentration, 120 minutes contact time and pH 3, 454.81 mg/g quantity was adsorbed. The highest adsorption percentage removal efficiency was obtained at room temperature. Kinetic data fitted best to pseudo second order and the mechanism was diffusion governed. The kinetic models were further validated by sum of square error (SSE) and non-linear Chi-square statistical models (X2). The values of the thermodynamic parameters: standard enthalpy change ΔH (-10.597 Jmol−1)to (-5558 Jmol−1.), standard entropy change, ΔS (-277.804 J mol−1 K−1)- to (-139.2595 J mol−1K−1) and the Gibbs free energy (ΔG) revealed that the adsorption process was feasible, spontaneous and exot...
Ife Journal of Science, 2018
Titanium dioxide (TiO) was prepared by Sol-gel method which involved hydrolysis of Titanium trich... more Titanium dioxide (TiO) was prepared by Sol-gel method which involved hydrolysis of Titanium trichloride 2 (TiCl) with concentrated hydrochloric acid and oxidation by hydrogen peroxide. Doping of the TiO was 3 2 effected at 10% Ni-TiO and 10% Co-TiO using aqueous solutions of nickel nitrate and cobalt nitrate 2 2 respectively. Characterization by X-ray Diffraction Crystallography (XRD) and Scanning Electron Microscopy (SEM) showed that the surface area and crystallinity of TiO increased through doping. The XRD and SEM data 2 confirmed the observed increase in the photocatalytic activities of the doped versus the undoped TiO 2 photocatalysts. Photocatalytic activities of both the doped and undoped TiO was investigated on the 2 o photodegradation of Alizarin red dye. With a constant dye concentration of 25 ppm and temperature of 40 C, it was observed that for all varying concentrations except 0.25 g/l of catalyst at 240 mins, the percentage degradation was of the order TiO < Co-TiO < Ni-TiO. At the 0.25 g/l concentration of catalyst at 240 mins, 2 2 2 the photocatalytic activities of the Ni-TiO and Co-TiO were observed respectively to be about 9 times and 12 2 2 times that of the TiO .
Journal of Applied Sciences and Environmental Management, 2017
The study focused on assessment of removal of cypermethrin and chloropyriphos in aqueous solution... more The study focused on assessment of removal of cypermethrin and chloropyriphos in aqueous solution using activated carbon made from Jatropha Curcas. Batch adsorption experiments were carried out under different conditions of parameters such as pH, contact time, adsorbent dosage, and initial concentration of the adsorbate on pesticide adsorption. The adsorption data were described by Langmuir and Freundlich adsorption model. Adsorption capacity of 92.73% and 92.26% of chloropyriphos and cypermetrin respectively were removed by 2g of the adsorbent per 50 cm 3 of initial concentration of 0.78 mg/l and 1.50 mg/l chloropyriphos and cypermetrin respectively .This was achieved at 90 min of the contact time and at optimum pH of 6.3.The study demonstrates that the activated carbon made from Jatropha Curcas can be effective in the adsorption of these two pesticides from water bodies. Equilibrium experiment results show that adsorption isotherms of cypermethrin and fit better to Freundlich adsorption isotherm while chloropyriphos fit better on the Langmuir adsorption isotherm © JASEM
Applied Water Science, 2015
Synthesis of nanoscale zerovalent manganese (nZVMn) by chemical reduction was carried out in a si... more Synthesis of nanoscale zerovalent manganese (nZVMn) by chemical reduction was carried out in a single pot system under inert environment. nZVMn was characterized using a combination of analytical techniques: Ultraviolet-Visible Spectroscopy, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Transmission Electron Microscopy, Energy Dispersive X-ray, BET surface area and Point of Zero Charge. The adsorption physicochemical factors: pH, contact time, adsorbent dose, agitation speed, initial copper ion concentration and temperature were optimized. The kinetic data fitted better to Pseudo second-order, Elovich, fractional power and intraparticle diffusion models and their validity was tested by three statistical models: sum of square error, Chi-square (v 2) and normalized standard deviation (Dq). Seven of the two-parameter isotherm models [Freundlich, Langmuir, Temkin, Dubinin-Kaganer-Raduskevich (DKR), Halsey, Harkin-Jura and Flory-Huggins] were used to analyse the equilibrium adsorption data. The Langmuir monolayer adsorption capacity (Q max = 181.818 mg/g) obtained is greater than other those of nano-adsorbents utilized in adsorption of copper ions. The equilibrium adsorption data were better described by Langmuir, Freundlich, Temkin, DKR and Halsey isotherm models considering their coefficient of regression (R 2 [ 0.90). The values of the thermodynamic parameters: standard enthalpy change DH°(?50.27848 kJ mol-1), standard entropy change DS°(203.5724 J mol-1 K-1) and the Gibbs free energy change DG°revealed that the adsorption process was feasible, spontaneous, and endothermic in nature. The performance of this novel nanoscale zerovalent manganese (nZVMn) suggested that it has a great potential for effective removal of copper ions from aqueous solution.
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Papers by Ezekiel Odebunmi