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    Biosorption of heavy metal ions on immobilized white-rot fungus Trametes versicolor
    (Elsevier, 2003) Bayramoglu, G; Bektas, S; Arica, MY
    Trametes versicolor mycelia were immobilized in carboxymethylcellulose, CMC, beads via entrapment, and the bead containing immobilized fungus spores were incubated at 30 degreesC for 3 days to attain uniform growth on the bead surface. After incubation, the live and heat inactivated immobilized fungus on the CMC beads were used for the biosorption of Cu2+, Pb2+ and Zn2+ ions. Plain CMC beads were used as a control system. The biosorption of Cu2+, Pb2+ and Zn2+ ions by the CMC and both live and inactivated immobilized preparations increased as the initial concentration of Cu2+, Pb2+ and Zn2+ ions in the medium increased. The maximum biosorption capacities for both immobilized live and heat inactivated Trametes versicolor were 1.51 and 1.84 mmol Cu2+, 0.85 and 1.11 mmol Pb2+ and 1.33 and 1.67 mmol Zn2+ per g of dry biosorbents, respectively. Biosorption equilibrium was established in about 1.0h and the equilibrium was well described by Langmuir and Freundlich isotherms. A temperature change in the range of 15-45 degreesC did not affect the biosorption capacity. The affect of pH was also investigated and the maximum adsorption of Cu2+, Pb2+ and Zn2+ ions on the CMC and both live and inactivated immobilized fungal biomass was observed between pH 4.0 and 6.0. The CMC beads with the immobilized fungus can be regenerated using 10 mM HCl, with up to 97% recovery of the metal ions; the biosorbents reused up to five biosorption-desorption cycles without any major loss in the biosorption capacity. (C) 2003 Elsevier B.V. All rights reserved.
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    Biosorption of Hg2+, Cd2+, and Zn2+ by Ca-alginate and immobilized wood-rotting fungus Funalia trogii
    (Elsevier, 2004) Arica, MY; Bayramoglu, G; Yilmaz, M; Bektas, S; Genc, O
    Funalia trogii biomass was immobilized in Ca-alginate gel beads. The live and beat inactivated immobilized forms were used for the biosorption of Hg2+, Cd2+ and Zn2+ ions by using plain Ca-alginate gel beads as a control system. The effect of pH was investigated and the maximum adsorption of metal ions on the Ca-alginate and both live and inactivated immobilized fungal preparations were observed at pH 6.0. The temperature change between 15 and 45 degreesC did not affect the biosorption capacity. The biosorption of Hg2+, Cd2+ and Zn2+ ions on the Ca-alginate beads and on both immobilized forms was studied in aqueous solutions in the concentration range of 30-600 mg/L. The metal biosorption capacities of the heat inactivated immobilized E trogii for Hg2+, Cd2+ and Zn2+ were 403.2, 191.6, and 54.0 mg/g, respectively, while Hg2+, Cd2+ and Zn2+ biosorption capacities of the immobilized live form were 333.0, 164.8 and 42.1 mg/g, respectively. The same affinity order on a molar basis was observed for single or multi-metal ions (Hg2+ > Cd2+ > Zn2+). The Langmuir and the Freundlich type models were found to exhibit good fit to the experimental data. The experimental data were analyzed using the first-order (Langergren equations) and the second order (Ritchie equations). The experimental biosorption capacity with time is found to be best fit the second-order equations. The alginate-fungus system could be regenerated by washing with a solution of hydrochloride acid (10 mM). The percent desorption achieved was as high as 97. The biosorbents were reused in five biosorption-desorption cycles without significant loss of their initial biosorption capacity. (C) 2004 Elsevier B.V. All rights reserved.
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    Uranium recovery by immobilized and dried powdered biomass: characterization and comparison
    (Elsevier Science Bv, 2003) Genc, O; Yalcinkaya, Y; Buyuktuncel, E; Denizli, A; Arica, MY; Bektas, S
    Immobilized and dried powdered Trametes versicolor and Phanerochaete chrysosporium basidio of spores were used for the recovery of uranium from aqueous solutions. The biosorption of UO22+ ions by the carboxymethylcellulose and immobilized and heat-killed fungal mycelia of T versicolor and P chrysosporium was studied from aqueous solutions in the concentration range of 100-1000 mg/l. The biosorption of UO22+ ions by the carboxymethylcellulose and immobilized and dried powdered preparations increased as the initial concentration of uranium ions increased in the medium. Maximum biosorption capacities for immobilized and dried powdered fungal mycelia of T versicolor and chrysosporium was found as 309.1 mg UO22+ /g and 158.0 mg UO22+ /g, respectively; whereas the of UO22+ ions adsorbed on the plain carboxymethylcellulose beads was 29.2 mg/g. Biosorption equilibria were established in about 20 min and the correlation regression coefficients show that the adsorption process can be well-defined by Langmuir equation. The effect of pH was also investigated and the maximum adsorption UO22+ ions on the carboxymethylcellulose and both live and heat-inactivated immobilized fungal mycelia were observed at pH 4.5. The carboxymethylcellulose-fungus beads could be regenerated using 10 mM HCl, with up to 98% recovery. The biosorbents were used in five biosorption-desorption cycles and no considerable loss in the biosorption capacity was observed. For the synthetic wastewater samples, it was observed that immobilized and dried powdered fungal mycelia of T versicolor and P chrysosporium removed 91.8% and 66.8% of uranium ions, respectively. (C) 2003 Elsevier Science B.V. All rights reserved.