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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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    Entrapment of white-rot fungus Trametes versicolor in Ca-alginate beads: preparation and biosorption kinetic analysis for cadmium removal from an aqueous solution
    (Elsevier Sci Ltd, 2001) Arica, MY; Kacar, Y; Genc, O
    The biosorption of cadmium ions onto entrapped Trametes versicolor mycelia has been studied in a batch system. The maximum experimental biosorption capacities for entrapped live and dead fungal mycelia of T. versicolor were found as 102.3 +/- 3.2 mg Cd(II) g(-1) and 120.6 +/- 3.8 mg Cd(II) g(-1), respectively, Biosorption equilibrium was established in about 1 h and biosorption was well described by the Langmuir and Freundlich biosorption isotherms. The change in the biosorption capacity with time was found to fit the pseudo-second-order equation. Since the biosorption capacities were relatively high for both entrapped live and dead forms, those fungal forms could be considered as suitable biosorbents for the removal of cadmium in wastewater-treatment systems. The biosorbents were reused in three consecutive adsorption/desorption cycles without a significant loss in the biosorption capacity. (C) 2001 Elsevier Science Ltd. 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.