Browsing by Author "Onu, Uchenna Lynda"

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    Chemo-remediation of crude oil polluted soils obtained from recent polluted site in oil producing environs in Rivers State Nigeria
    (eSciPub, 2019) Iwu, Irenus Chinonye; Onu, Uchenna Lynda; Nkwoada, Amarachi; Onwumere, Fidelis
    The chemo- remediation of crude oil polluted soils from recent pollution sites in oil producing environs in River state was carried out by both in vivo and in vitro methods using macro-soil nutrients ( Nitrate, Phosphate and Potassium) as index for remediation. The soil samples were labeled A, B, C, D1 to D6, sample A was obtained from pollution free site used as a control.Sample C was crude oil polluted soil not treated with surfactant, sample B was crude oil polluted soil leached with surfactant and not mineralized. Samples D1-D6 were polluted soil samples, leached with surfactant and mineralized with fertilizer. The samples were leached with linear alkyl benzene sulphonate (LABS) and later mineralized with Nitrate, Phosphate and Potassium (N.P.K) fertilizer and returned to the site of excavation to fallow for four months. The samples were later re-excavated and taken to the laboratory for analysis. Nitrate and phosphate contents were obtained with the aid of spectrum lab 725 UV visible spectrophotometer and potassium content was determined by use of a flame photometer. Results showed that sample A had nitrate concentration of 330ppm, sample B had concentration of 21ppm, sample C had a concentration of 54ppm while samples D-D6 had concentrations ranging from300ppm to 420ppm.Similarly, The phosphate concentrations were 68.50ppm, 17.00ppn, 28.00ppm and 48.80-136.40ppm for sample A, B, C.D1-D6 respectively. The potassium concentrations were not different as concentrations of 46ppm, 12ppm, 28ppm and 38ppm-64ppm was recorded for samples A, B, C, and D1-D6 respectively. These results revealed that crude oils not only renders soils unusable but also destroys the nutrient availability in soils. The soils can therefore quickly be reclaimed by leaching them with surfactants and mineralizing them with adequate inorganic fertilizer.
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    Physicochemical analysis and mineralogical composition of Enugu coal In Nigeria for potential utilization
    (U. P., 2017) Nwoko, Christopher Ikpeamadi; Nkwoada, Amarachi Udoka; Onu, Uchenna Lynda
    The abundance of coal in certain regions of Nigeria had been described as an alternative energy solution. The potential information obtained from the physicochemical and mineralogical characterization of coal samples in such regions has enabled scientist and government to make well informed decisions. Coal samples were obtained from Okpara Mine in Enugu state Nigeria and subjected to proximate, ultimate and mineralogical analyses. The results showed that the coal had uneven particle distribution with higher content of fixed carbon and lower amount of hydrogen and volatile matter. The mineral analyses showed that the coal was rich in silicon and aluminum. The rank was bituminous coal that can be utilized for power generation, steel industry, glass manufacturing and thermite process
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    Phytochemical and GC/MS analysis of the rhizome of zingiber officinale plant grown in eastern part of Nigeria
    (U. P., 2018) Iwu Irenus Chinonye; Oze, Rita N; Onu, Uchenna Lynda; Nkwoada, Amarachi; Ukaoma, Adanma A
    Phytochemical and GC-MS analysis of zingiber offinale was carried out in the laboratory and with the aid of SHIMAZU Japan Gas Chromatography 5890-11 with a fused GC column OV 101 coated with polymethyl silicon (0.25 mm x 50 m). The result obtained confirmed the presence of alkaloids, flavonoids, saponins, glycosides, tannins and phenols in the plant. Twelve peaks were obtained from the he spectra of the GC-MS. peak 1 corresponds to Furan-3-carboxaldehyde with m/z 128 and molecular formulae C6H8O2, peak 2 was identified as Benzene -1-(1,5-dimethyl-4-4hexenyl)-4-methyl m/z 202 with molecular formulae C15H22. Peak 3 as ,1-,3-cyclohexadiene-5- (,5 diethyl-4-hexenyl -2-methyl (zingiberene) m/z 204 with molecular formulae C15H24, peak 4 as Alpha farnesene m/z 204 with molecular formulae C15H24. Peaks 5,6,7,8,9,10,1,12 occurred at m/z; 220,204, 194,242,,256,296,282, 296 corresponding to butylated hydrotoulene, C15H24,,cyclohexene-3- (1,5-dimethyl-4-hexenyl-6- methelene C15H24, 2-butanone-4-(4-hydroxy-3-methoxyphenyl C11H14O3, methyl tetra decanoate C15H32O2, n-hexadecanoic acid C16H32O2, 9-octadecenoic acid methyl ester C09H26O2, Octadec-9-enoic acid, C18H34O2, Gingerol C17H28O4 and Ricinoeic acid C18H24O2 respectively
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    Synthesis, characterization and corrosion inhibition applications of cerium (iii) metal complexes derived from some salicyaldehyde-based shiff bases
    (Federal University of Technology, Owerri, 2025-06) Onu, Uchenna Lynda
    This present research work focuses on the synthesis , characterization and corrosion inhibition efficiency of three synthesized salicylalde - based Schiff bases with their Cerium(III) complexes, namely: 2-hydroxyphenyl-phenylimine or (Salicyalideneaniline (SALAN)), Bis(2- hydroxyphenyl) imine or (Salicyalidene-2- aminophenol (SAL2AP)), Bis (2-hydroxyphenyl) -1,2- Benzenediimine or (Salicyalidene-O-phenylenediamine (SALPD)), Ce(III)-2-hydroxyphenylphenylimine (CeSALAN), Ce(III)-Bis(2-hydroxyphenyl) imine (CeSAL2AP), and Ce(III)-Bis (2- hydroxyphenyl) -1,2-Benzenediimine (CeSALPD) in 1 M HCl solution. The compounds were characterized by physicochemical methods such as colour, melting point, solubility test, molar conductivity measurement, magnetic usceptibility and elemental analysis. There is variation in colour, pH, melting point, conductivity, and elemental compositions of the of the Schiff bases compared to their metal complexes. Magnetic susceptibility measurements values recorded for the metal complexes shows their paramagnetic nature. The high molar conductivity values of the metal complexes (> 0.1 mSCm2 ) shows their electrolytic nature, while the Schiff bases were found to be non- electrolytic. The compounds were also analyzed spectrally by Uv. Vis. Spectroscopy, 1 H, and 13C NMR, FTIR, and EDXRF. The effect of inhibitor- concentration, temperature, and immersion time, on the inhibition efficiency of the compounds were studied by weight loss methods. ElS technique was used to investigate the nature of the protective film, EIS measurement shows that the addition of the inhibitors into the corrosion medium inhibited corrosion by increasing the system resistance (Rs), transfer charge resistance (Rct) while reducing the double layer capacitance (Cdl). PDP polarization techniques were used to study the nature of the inhibitors, and they were found to be mixed- type inhibitors. The corrosion potentials (Ecorr), and corrosion current (Icorr) due to the blank was reduced in the presence of the inhibitors. Increase in IE was observed due to increase in concentration of the inhibitors, with highest I.E value of 82.95 % recorded for the overall best inhibitor–compound CeSALPD at concentration of 0.4 mmol/dm3 . Effect of temperature on IE of inhibitors at temperature of 30 oC, 40 oC, 50 oC, 60 oC, and 70 oC shows decrease in IE due to increasing temperature (i.e. physical adsorption process). Thermodynamics parameters calculated for the inhibited reaction system shows increase in values of enthalpy (∆H), entropy (∆S), and activation energy (∆Ea) compared to values for blank. This obtained positive values of ∆ H shows endothermic nature of the reaction system, and negative values of ∆S shows reduction in disorderliness of the system due to the action of the inhibitors. Negative values for ∆G, obtained for the inhibited systems shows the spontaneous adsorption process. Effect of immersion time on IE of the compounds shows decrease in I.E with immersion time (i.e. physisorption adsorption process). Langmuir, Temkin, and Frumkin models were used to determine the adsorption mode of the compounds. Langmuir model with regression square (R2 ) value upto 0.99, best suits the adsorption process. Generally, for all the analytical techniques employed for the study of the IE, i.e. (weight- loss method, PDP and EIS), the I.E of the metal complexes were found to be higher than those of the parent Schiff bases. The quantum chemical parameters obtained from the Computational analysis and modelling of the Schiff bases such as EHOMO, ELUMO, shows that the reactivity of the Schiff bases follow the order: SALPD > SALAN > SAL2AP. The result from the weight–loss method is in agreement with the computational analysis. Conclusively, the compounds under study performed excellently as inhibitors, however, due to physisorption process of adsorption of the inhibitor molecules on the mild- steel surface, the compounds may not efficiently inhibit corrosion for a long - term duration. Hence, synergism with nano particles such as metal oxides i.e., (ZnO, TiO2, Al2O3), may enhance their IE for the longterm process.