Browsing by Author "Nwoko, Christopher Ikpe Amadi"

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    An experimental investigation of pristine barite adsorption on sodium oleate and sodium palmitate
    (Science Publishing Group, 2018) Nwoko, Christopher Ikpe Amadi; Nkwoada, Amarachi Udoka; Okoji, Josephine,; Opah, Solomon
    Characterization of the pristine barite mineral was established using a scanning electron microscope (SEM) and Fourier Transform Infra-Red (FTIR). Barite was applied for sodium oleate and sodium palmitate adsorption in aqueous solutions. Equilibrium adsorption data were fitted into two adsorption isotherms, three kinetic models and thermodynamic study. The concentration of the ion and pH in the solution proved to be a controlling factor in the adsorption process. Sodium oleate and sodium palmitate soaps adsorbed strongly onto the barite mineral at pH 9 and a temperature of 293k. They result was affected by the high bulk density and chemical resistance nature of barite indicated by successive increase in dosage amount. The effect of concentration and time typically gave a C-type adsorption isotherm. Adsorptive isotherm showed that sodium palmitate adsorption over natural barite was better described by the Langmuir adsorption isotherm while oleate desorption gave a good fitting with Freundlich isotherm. The adsorptive kinetics of sodium palmitate fitted well into pseudo 1st order and 2nd order kinetics. Intra particle diffusion was not the rate-determining step. Thermodynamic study showed a physiosorption that was exothermic. Hence the findings showed that pristine barite absorbs at optimum pH and temperature of 9 and 293k.
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    Novel linearized kinetic modeling of starch hydrolysis
    (U. P., 2017-06-09) Nwoko, Christopher Ikpe Amadi; Nkwoada, Amarachi Udoka; Ihuoma, Peterclever Chidi
    The hydrolysis of starch into glucose by acid and enzyme techniques has recorded higher glucose recovery and optimization of processes, but lacks the fitting of the results into a kinetic linear model. The application of kinetic linearized model effect of temperature on pH and acid concentration during hydrolysis of starch into glucose was studied. The experiment was conducted at different durations using reported preparatory techniques and average values of triplicates were reported. The maximum glucose yield of 18.20 mg/ml was observed on 4 hours at 60°C from acid hydrolysis and similarly observed at 4 hours at 100°C for enzym e hydrolysis. The lowest glucose yield of 10.0 mg/ml and 11.1 mg/ml were both recorded at 30 minutes duration for acid and enzyme hydrolysis respectively. The correlation coefficient of acid hydrolysis when starch was hydrolyzed for 2 hours at 80°C had a value of 1 (line of best fit) while the w eakest linear relationship (0.715) was obtained was in enzymatic hydrolysis when starch was hydrolyzed at 4 hours for 80°C Hence, the highest glucose yield was not automatically the most efficient process. The linear model equations showed that acid hydrolysis of starch had a positive energetic interaction while enzymatic hydrolysis had a negative energetic interaction. The slope and intercept of acid hydrolysis were all positive and indicated a positive relationship with parameters. All enzymatic hydrolysis had negative slope and indicated inverse relationship with the parameters. Therefore, the model allows researchers to make well interpretations of their results using linearized kinetic model.