YYÜ GCRIS Basic veritabanının içerik oluşturulması ve kurulumu Research Ecosystems (https://www.researchecosystems.com) tarafından devam etmektedir. Bu süreçte gördüğünüz verilerde eksikler olabilir.

Browsing by Author "Yunus, Onal"

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    Article
    Adsorption and Kinetics of Hazardous Dye Rhodamine-B From Aqueous Solutions With Activated Carbon-Based Low-Rank Coal
    (Parlar Scientific Publications (p S P), 2011) Tolga, Depci; Yunus, Onal; Selim, Erdogan; Canan, Akmil-Basar
    Activated carbon was prepared from Tuncbilek-Kutahya (Turkey) lignite by chemical activation with KOH (impregnation ratio 1:2). Pore characteristics of the activated carbon, such as BET surface area, pore volume, size distribution and the diameter of pores, were determined. BET surface area was found to be 902 m(2)/g, and other characteristic values are as follows: S-micro:560 m(2)/g V-total: 0.50 cm(3)/g, V-micro: 0.30 cm(3)/g and average pore diameter: 2.21 nm (4 V/A by BET). The prepared activated carbon was used to adsorb Rhodamine-B (RB) from aqueous solution in a batch reactor. The adsorption isotherm of process could be best identified using the Langmuir model since it gave a better fit and had a higher R-2 value (0.9908) than Freundlich model. The kinetics of the adsorption of RB was tested using a pseudo-second order equation and an intraparticle diffusion model. Adsorption capacity was determined to be between 1.80-2.55 10(-4) mol.g(-1). It was found that the boundary layer thickness increased as the temperature increased (50.641 - 64.271).
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    Article
    Equilibrium, Kinetic and Thermodynamic Studies of Nickel Adsorption Onto Natural and Modified Kaolinites
    (Parlar Scientific Publications (p S P), 2011) Riza, Kul Ali; Tolga, Depci; Ihsan, Alacabey; Salih, Alkan; Yunus, Onal
    Availability of clay and its modified forms makes them a viable candidate for an alternative adsorbent. In this study, kaolinite and modified kaolinites were tested to determine their suitability for removal of Ni (II) ions from aqueous medium. Parameters, such as kaolinite type, concentration of Ni ions, time and temperature of interaction, were investigated to evaluate the adsorption capacity, kinetics, equilibrium and thermodynamic properties of Ni (II) adsorption. The adsorption isotherms followed Freundlich, Dubinin-Redushkevich (D-R) and Halsey isotherms but DR isotherm was chosen due to its applicability to all adsorption isotherms. The kinetics of adsorption mechanism of Ni (II) was tested using pseudo-first-order, pseudo-second-order and intraparticle diffusion models. The results showed that adsorption mechanism could be perfectly explained with pseudo-second order equation. The intraparticle diffusion of Ni (II) ions within the natural and modified kaolinite was more likely to be governed by the diffusion step. Adsorption mechanism for activated kaolinite was intra-particle diffusion model. Ni (II) adsorptions on activated kaolinites were exothermic and spontaneous in nature. The results of this study indicated that activated kaolinite can be employed for removal of Ni (II) from industrial wastewater.