School of Environmental Sciences

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https://repository.futo.edu.ng/handle/20.500.14562/1243

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Browsing School of Environmental Sciences by Subject "Adsorption"

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    Adsorption of cupper (II) ion on heterogeneous surfaces of selected low-cost precursors; an application of isotherm, thermodynamic and kinetic models
    (U. P., 2015-01) Uzoije , Atulegwu .Patrick; Okolie, Justus I.; Njoku, P. C.; Enwereuzo., Uzo
    Cupper ions occur naturally in the environment and also prevalent in the waste from metal smelting industries through which it gets to the environment. Excessive intake of cupper results to adverse health effects on plant, animals and humans. The present study therefore studied the Adsorption of Cupper (II) ion on three activated bio-adsorbents; Unripe plantain peel, pineapple peel and commercial activated carbon. The activated carbons were characterized for surface morphology and functional groups for removal of Cupper (II) ion from aqueous solution. Batch process was adopted to study the time, temperature effect and isotherm equilibrium of Cupper (II) ion on. Adsorption of Cupper (II) ion on the three adsorbents got to equilibrium at between 80-100 minutes. Adsorption capacity of the three adsorbent was in this order at all temperature values; Unripe plantain peel greater than pineapple peel and greater than commercial activated carbon. Adsorption of Cupper ion increased with temperature, adsorption got to its plateau at 45oC and began to decrease. Langumuir-freunlich and Dubini-Radushkevichmodels were applied to analyze the Isotherm data. Langumuir-freunlich described the data better than Dubini-Radushkevich. Also, Pseudo-first order, pseudo-second-order, and intra-particle diffusion models were applied to test the kinetic data, pseudo-second-order fitted the data better than pseudo-first order. Pore-pore particle diffusion was observed to be the controlling step. Endothermic and non- spontaneous processes characterized Cupper ion adsorption on the three adsorbents .
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    Analysis of thermodynamics, kinetics and equilibrium Isotherm on Fe3+/Fe2+ adsorption onto palm kernel shell activated carbon (PKSAC): A low-cost adsorbent
    (SCIENCEDOMAIN international, 2014-01-15) Uzoije, Atulegwu Patrick; Uche, Cosmas Chinedu; Ashiegbu, Darlington
    Adsorption of Fe3+/Fe2+ from a polluted shallow well water onto a palm kernel shell activated carbon (PKSAC) has been studied. Batch experiment was adopted to study the Removal efficiency of Fe3+/Fe2+ on varying contact time, temperature, adsorbent loading and concentrations. Equilibrium isotherm and kinetic were also studied. Removal efficiency progressed with contact time till the peak adsorption time of 100 minutes when the efficiency remained at equilibrium. Also, removal efficiency got to equilibrium at the peak values of 80ºC, 4.8g and 12.5mg/l for temperature, adsorbent loading and concentration variations respectively. The adsorption isotherm models fitted the isotherm data got at 25ºC, 40ºC and 80ºC in this order; Langmuir > Temkin>Freunlich. The dimensionless separation factor of 0.012, 0.017 and 0.015 for 25ºC, 40ºC and 80ºC respectively confirmed favorable adsorption of Fe3+/Fe2+ on the PKSAC adsorbent. Langmuir adsorption capacity increased from 203.9mg Fe3+/Fe2+/g to 389.3 mg Fe3+/Fe2+/g when the temperature increased from 25ºC to 40ºC but decreased to 308.1 mg Fe3+/Fe2+/g at temperature of 80ºC. The kinetic models described the kinetic study data got at 25ºC, 40ºC and 80ºC as follows; power-function>second-order>Elovick>intra-diffusion>first-order kinetics. Mass transfer through liquid film diffusion controlled the adsorption of Fe3+/Fe2+ onto PKSAC. Negative values of the Thermodynamic parameters (Δ􀀂􀀃 , Δ􀀅􀀃 and Δ􀀆􀀃) got at various temperature values showed favorability of adsorption of Fe3+/Fe2+ onto PKSAC.nIt is therefore concluded that PKSAC removed Fe3+/Fe2+ from aqueous solution.