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Kinetics and Thermodynamic Study of the Acetylation of Cucumeropsis mannii Seed Shell
Amalachukwu Ifeyinwa Obi,
Vincent Ismael Egbulefu Ajiwe,
Ozioma Juliana Anekwe,
Emeka Christian Ezeudu,
Cecilia Nkemjika Aduaka
Issue:
Volume 11, Issue 2, April 2023
Pages:
45-50
Received:
3 March 2023
Accepted:
21 March 2023
Published:
31 March 2023
Abstract: The use of lignocellulosic materials for oil sorption from aqueous medium has directed attention to acetylation as a means of increasing the hydrophobicity of these materials. In this paper, acetylation of Cucumeropsis mannii seed shell, a readily available agricultural waste, was studied. Effects of different acetylation conditions on the extent of acetylation of the seed shell was investigated. The kinetics of the acetylation process was studied using pseudo first order, pseudo second order, and intraparticle diffusion models. The thermodynamics of the acetylation process was also studied. FTIR analysis provided evidence of successful acetylation of the seed shell. The extent of acetylation increased with increase in acetylation duration, temperature and catalyst concentration. Pseudo second order kinetics best described the acetylation process, with minimum extent of acetylation and rate constant values of 0.317 and -0.0148 min-1, respectively. Thermodynamic studies revealed that the acetylation process was endothermic in nature. The critical extent of acetylation, heat capacity at constant pressure, and change in entropy values were 1.002, 0.162 kJ.mol-1.K-1, and 0.020 kJ.mol-1.K-1, respectively. The acetylation process was spontaneous at temperatures of 328 K ‒ 348 K, but non-spontaneous at lower temperatures (308 K and 318 K). The critical temperature of acetylation was 419 K, which shows that acetylation of CMSS can easily take place at mild conditions.
Abstract: The use of lignocellulosic materials for oil sorption from aqueous medium has directed attention to acetylation as a means of increasing the hydrophobicity of these materials. In this paper, acetylation of Cucumeropsis mannii seed shell, a readily available agricultural waste, was studied. Effects of different acetylation conditions on the extent o...
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Determination of Toxic and Trace Heavy Metals in the Soil of Two Different Dumpsites: A Case Study of Ojota and Oko Filling Dumpsites, Lagos State
Moronkola Bridget Adekeni,
Alegbe Monday John,
Okpala-Chunonso Angela,
Adewusi Anuoluwapo
Issue:
Volume 11, Issue 2, April 2023
Pages:
51-55
Received:
26 January 2023
Accepted:
8 March 2023
Published:
13 April 2023
Abstract: Heavy metals are metallic elements with a relatively high density that are dangerous or hazardous at low concentrations and pose a serious threat to people and the environment. The purpose of this research is to ascertain the concentrations of heavy and trace metals in the Lagos State communities of Ojota and Oko Filling. The soil samples taken from the dumpsites were treated using the digestion process. After being placed into a sampling vial, the mixed solution from the digestion process was then taken for measurement using inductively coupled plasma optical emission spectroscopy (ICP-OES). Samples taken from the dumpsites at Ojota and Igando contained 12.52% and 4.44% of moisture, respectively. The analysis's findings showed that the average concentrations of Fe (42.429 mg/L), Zn (2.070 mg/L), Ca (7.140 mg/L), P (9.06 mg/L), Cd (0.022 mg/L), Cr (0.042 mg/L), Cu (0.135 mg/L), Pb (1.280 mg/L), and Ni (0.123 mg/L) at the Ojota dumpsite were all within the WHO/FAO standards' tolerable limits and did not pose any risk. While, Fe (94.784 mg/L), Zn (11.564 mg/L), Ca (45.243 mg/L), Cd (2.838 mg/L), Cr (0.046 mg/L), Cu (0.215 mg/L), and Ni (0.22 mg/L) are the mean concentrations, respectively. In conclusion, the results from the Oko – filling dumpsites shows that the heavy metals from the soil is highly toxic and are such harmful to the environment and detrimental to human life than Ojota dumpsites.
Abstract: Heavy metals are metallic elements with a relatively high density that are dangerous or hazardous at low concentrations and pose a serious threat to people and the environment. The purpose of this research is to ascertain the concentrations of heavy and trace metals in the Lagos State communities of Ojota and Oko Filling. The soil samples taken fro...
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Spectroscopic Studies and X-ray Structural of Dinuclear Lanthanide (III) Complexes Derived from N'-(2-hydroxy-3-methoxybenzylidene) Nicotinohydrazide
Fatou Barr,
Papa Samba Camara,
Amadou Guèye,
Sofia Zazouli,
Nathalie Gruber,
Farba Bouyagui Tamboura,
Moussa Dieng,
Mohamed Gaye
Issue:
Volume 11, Issue 2, April 2023
Pages:
56-63
Received:
2 April 2023
Accepted:
17 April 2023
Published:
27 April 2023
Abstract: Two Schiff bases (H2L), derived from o-vanillin and nicotinic hydrazide, and its complexes with some lanthanides (Y, Ce, Yb, Pr, Gd and Tb) have been synthesized. These compounds have been characterized by means of elemental analysis, UV–Vis spectroscopy, FTIR spectroscopy, 1H and 13C NMR (for H2L), molar conductance and room temperature magnetic measurements. The compounds are found isostructural and are formulated as {[(Z)(η2-OOCH3)Ln](-L)2[Ln(η2-OOCH3)(Z)]} (Z = H2O for Ln = Y, Ce, Pr, Gd or Tb and Z = OS(CH3)2 for Ln =Yb). The two ligand molecules act in their dideprotonated forms through one azomethine nitrogen atom, one phenoxo oxygen atom and one iminolate oxygen atom. The two Ln (III) ions are bridged by two phenoxo oxygen atoms, forming a dinuclear complex. Single crystal X-ray analysis of the ytterbium complex has revealed the nature of the structure {[(OS(CH3)2)(η2-OOCH3)Yb](-L)2[Yb(η2-OOCH3)(OS(CH3)2)]} (3). The complex crystallizes in the monoclinic space group C2/c with cell parameters of a = 13.0391(6) Å, b = 15.1199(6) Å, c = 20.7239(7) Å, β = 105.671(2)°, V = 3933.8(3) Å3, Z = 4, R1 = 0.025, wR2 = 0.65. The ytterbium atoms are eight-coordinated, and their coordination polyhedron are best described as a square antiprismatic geometry. The aromatic rings of the ligand molecule are twisted with dihedral angle of 29.23 (1)° between their mean planes.
Abstract: Two Schiff bases (H2L), derived from o-vanillin and nicotinic hydrazide, and its complexes with some lanthanides (Y, Ce, Yb, Pr, Gd and Tb) have been synthesized. These compounds have been characterized by means of elemental analysis, UV–Vis spectroscopy, FTIR spectroscopy, 1H and 13C NMR (for H2L), molar conductance and room temperature magnetic m...
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Comparative Spectrophotometric Determination of Neodymium (III), Praseodymium (III), Samarium (III) and Terbium (III) in Aqueous and Micelle Media
Uwanta Emaime Jimmy,
Nicholas Eno-obong Sunday,
Ikpe Edidiong Emmanuel,
Ocheni Adejoh,
Ukoha Pius Onyeoziri
Issue:
Volume 11, Issue 2, April 2023
Pages:
64-70
Received:
4 April 2023
Accepted:
20 April 2023
Published:
27 April 2023
Abstract: This research work titled comparative spectrophotometric determination of neodymium (III), praseodymium (III), samarium (III) and terbium (III)in aqueous and micelle media using schiff base was carried out with the aim to use a simple, rapid and sensitive spectrophotometric method for the determination of Nd (III), Pr (III), Sm(III) and Tb(III) using the Schiff base 2,2′-((1E,1′E)-(1,2-phenylenebis(azanlylidene)bis (methanylylidene))diphenol (BSOPD) as a ligand. Spectral and absorbance measurements were carried out using UV/Visible Spectrophotometer (Jenway model no.: 6305) with 1-cm matched quartz cells. This method of experiment was based on the formation of green coloured complexes, upon the reaction of Nd(III) and Pr(III) and a brown coloured complexes for Sm(III) and Tb(III) having a maximum absorbance of 376, 386, 384 and 380 nm respectively. The comparative analysis of the complexes formed in aqueous and in micellar media were investigated in this study. In the obtained results, it was discovered that, Beer’s law was obeyed in the concentration ranges of 0.001 - 0.02 ppm. The molar absorptivity was found to be in the range of 7,776- 23,197 and 27,087 dm3mol-1cm-1 and the Sandell’s sensitivity for the compounds analyzed were in the ranges of 6.13-19.34 g cm-2. The increase in absorbance in the presence of the surfactants is due to micelle formation. The reactants were bound in a small volume of stern layer of the micelle leading to a greater increase in concentration effect. This effect in concentration reaches a maximum before decreasing due to dilution effect occasioned by increase in metal ion concentration.
Abstract: This research work titled comparative spectrophotometric determination of neodymium (III), praseodymium (III), samarium (III) and terbium (III)in aqueous and micelle media using schiff base was carried out with the aim to use a simple, rapid and sensitive spectrophotometric method for the determination of Nd (III), Pr (III), Sm(III) and Tb(III) usi...
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