Yazar "Akkaya, Gulbahar" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • [ X ]
    Öğe
    Application of Some Domestic Wastes as New Low-Cost Biosorbents for Removal of Methylene Blue: Kinetic and Equilibrium Studies
    (Taylor & Francis Inc, 2014) Akkaya, Gulbahar; Guzel, Fuat
    In this study, parsley stalks (PS), cucumber peels (CP), and watermelon seed hulls (WSH) were used as novel low-cost adsorbents to remove methylene blue (MB) from aqueous solutions. The biosorption of MB onto PS, CP, and WSH was investigated as a function of pH (2-10), initial dye concentration (25-450mg/L), temperature (293-333K), ionic strength (0.0-1.0mol/L NaCl), and biosorbent dose (0.1-1.0g/50mL). While the biosorption of MB on PS followed the Freundlich isotherm, biosorption on CP and WSH followed the Langmuir isotherm at all the temperatures studied. The monolayer biosorption capacities of PS, CP, and WSH were found to be 400, 111.11, and 57.14mg/g, respectively. The biosorption of MB onto PS followed pseudo-second-order kinetics, and the biosorption onto CP and WSH followed pseudo-first-order kinetics. Thermodynamic studies showed that the biosorption of MB onto PS, CP, and WSH was spontaneous and feasible. The pH(zpc) values (of) PS, CP, and WSH were found to be 6.26, 6.42, and 6.83, respectively. Desorption studies were also carried out with various desorbing agents. HCl and H3PO4 were more effective desorbents than other desorbents used.
  • [ X ]
    Öğe
    Evaluation of Pomegranate (Punica Granatum L.) Pulps for the Removal of Copper(II) Ions: Kinetic, Equilibrium, and Desorption Studies
    (Taylor & Francis Inc, 2014) Guzel, Fuat; Aksoy, Onder; Akkaya, Gulbahar
    Pomegranate pulp has been used as novel adsorbent for removing Cu(II) ions from aqueous solution. The optimum conditions for removal of Cu(II) ions were found to be pH 5.32, biosorbent dose 0.1g, contact time 120 minutes, initial concentration 50mg/L, and temperature 30 degrees C. The kinetic data were well fitted to the pseudo-second-order model. The biosorption process agreed with the Langmuir isotherm model. Maximum monolayer biosorption capacity was 7.30mg/g. Thermodynamic parameters suggest that the biosorption process is spontaneous and exothermic. Desorption studies were carried out with different desorbing agents.
  • [ X ]
    Öğe
    Kinetics of the adsorption of reactive dyes by chitin
    (Elsevier Sci Ltd, 2007) Akkaya, Gulbahar; Uzun, Ilhan; Guzel, Fuat
    The effect of initial concentration, temperature, shaking rate and pH on the adsorption of reactive yellow 2 (RY2) and reactive black 5 (RB5) by chitin (Sigma C 9213) was investigated. Experimental data obtained at different temperatures for the adsorption of each dyestuff by chitin were applied to pseudo first-order, pseudo second-order and Weber-Morris equations, and the rate constants of first-order adsorption (k(1)), the rate constants of second-order adsorption (k(2)) and pore diffusion-rate constants (k(p)) at these temperatures were calculated, respectively. In addition, the adsorption isotherms of each dyestuff by chitin were also determined at different temperatures. (c) 2005 Elsevier Ltd. All rights reserved.