Browsing by Author "Njoku, P. C."

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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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    Phytoextraction and risk assessment synergy of three edible plants in mining area
    (U. P., 2018-08-11) Nwoko, C. I. A.; Nkwoada, A. U.; Onu, L. U.; Njoku, P. C.; Ogbonnaya, D. O.
    The phytoextraction and risk assessment synergy of Arachis hypogea (groundnut), Zea maize (Corn) and Citrullus colocynthis L. (Melon) was investigated at a mining area contaminated with Cd, Cu, Pb and Zn heavy metals. The metal concentrations in plant matter and soil were determined using AAS. The average pH at 5.2 showed a slightly acidic soil while the total organic content and electrical conductivity were low. The studied metals exceeded the Nigerian FEPA guidelines as well as EU threshold values at the sites. Increase in Cd concentration in the North and South caused a corresponding decrease in plant yield. The maize appreciably accumulated more Pb than melon and groundnut. The phytoplants at the West sampling point accumulated more Zinc and melon grown at the west accumulated highest zinc concentrations of up to 1100 mg/kg. The Presence of Cu metal at low concentrations favoured an equivalent increase in weight of harvested groundnut seed. The Coefficient of Variation (CV) showed a correlation that hyperaccumulators had equivalent higher CV distribution. The values of Cd, Cu and Pb exceeded the Health Risk Index value of 1 in all the three edible phytoplants. The Cd demonstrated the lowest Bioconcentration Factor of (0.03) within the sampling area, among studied metals and the three edible plants. Thus Target Hazard Quotient (THQ) results agreed with the Daily Intake of Metals (DIM) results, that consumption of any of the three edible plants are unsafe and poses a health risk to locals; hence, the synergy of THQ and DIM in evaluating experimental data is detected in this study.