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Öğe Application of NaOH treated Polyporus versicolor for removal of divalent ions of Group IIB elements from synthetic wastewater(Elsevier Sci Ltd, 2002) Satiroglu, N.; Yalcinkaya, Y.; Denizli, A.; Arica, M.Y.; Bektas, S.; Genç, O.Three different forms of Polyporus versicolor, i.e. alkali-pretreated, heat-inactivated and active, were used for the removal of the divalent ions of Group JIB elements from aquatic systems. The biosorption of Zn(II), Cd(II) and Hg(II) ions on three different forms of P. versicolor was studied in aqueous solutions in the concentration range of 30-700 mg/l. Maximum biosorption capacities of alkali-pretreated, heat-inactivated and active forms of P. versicolor was found as 139.3, 70.8, and 54.1 mg/g for Zn(II); 232.2, 118.2, and 90.0 mg/g for Cd(II) and 290.3 168.9, and 131.4 mg/g for Hg(11), respectively. For the divalent ions of Group 1111 elements, the order of affinity of the biosorbents was found as, NaOH treated > heat-inactivated > active. The order of the amount of metal ions adsorbed, on the other hand, was, Hg(II) > Cd(II) > Zn(II) on a weight base. The electro-negativities and standard electrode potentials of these elements show a definite trend with the biosorption capacity values. Biosorption equilibria were established in about 60 min and the equilibria were well described by Langmuir isotherms. Temperature change between 15 and 45 degreesC did not affect the biosorption capacity. The effect of pH was also investigated and the maximum biosorption of metal ions on the three different forms of P. versicolor were observed at pH 6.0. The reusability experiments and synthetic wastewater studies were carried out with the most effective form; alkali-pretreated P. versicolor. The biosorbent could be regenerated using 10 mM HCl solution, with up to 98% recovery and it could be reused in five biosorption-desorption cycles without any considerable loss in biosorption capacity. The alkali-treated P. versicolor removed 60, 73, and 81% of Zn(II), Cd(II) and Hg(II) ions from synthetic wastewater samples, respectively. (C) 2002 Elsevier Science Ltd. All rights reserved.Öğe Biosorption of cadmium from aquatic systems by carboxymethyleellulose and immobilized Trametes versicolor(Elsevier Science Bv, 2002) Yalcinkaya, Y.; Soysal, L.; Denizli, A.; Arica, M.Y.; Bektas, S.; Genc, O.Trametes versicolor basidio spores immobilized onto carboxymethylcellulose were used for the removal of cadmium ions from aqueous solutions. The biosorption of Cd(II) ions on carboxymethylcellulose and both immobilized live and heat-killed fungal mycelia of T. versicolor was studied from aqueous solutions in the concentration range of 30-700 mg/L. The biosorption of Cd(II) ions by the carboxymethylcellulose and both immobilized live and heat-inactivated immobilized preparations increased as the initial concentration of cadmium ions increased in the medium. Maximum biosorption capacity for immobilized live and heat-inactivated fungal mycelia of T. versicolor was found as 124 and 153 mg Cd(II)/g, respectively whereas the amount of Cd(II) ions adsorbed on the plain carboxymethylcellulose beads was 43 mg/g. Biosorption equilibria were established in about I h and the correlation regression coefficients show that the adsorption process can be well defined by Langmuir equation. The temperature change between 15 and 45 degreesC did not affect the biosorption capacity. The effect of pH was also investigated and the maximum adsorption of Cd(II) ions on the carboxymethylcellulose and both live and heat-inactivated immobilized fungal mycelia were observed at pH 6.0. 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 notable loss in the biosorption capacity was observed. 84% and 68% of cadmium ions were removed from synthetic waste water samples for 100 and 200 mg/L initial concentrations, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.Öğe Biosorption of mercury by carboxymethylcellulose and immobilized Phanerochaete chrysosporium(Elsevier Science Bv, 2002) Saglam, A.; Yalcinkaya, Y.; Denizli, A.; Arica, M.Y.; Genc, O.; Bektas, S.Phanerochaete chrysosporium basidiospores immobilized onto carboxymethylcellulose were used for the removal of mercury ions from aqueous solutions. The biosorption of Hg(II) ions onto carboxymethylcellulose and both immobilized live and heat-inactivated fungal mycelia of Phanerochaete chrysosporium was studied using aqueous solutions in the concentration range 30-700 mg l(-1). The biosorption of Hg(II) ions by the carboxymethylcellulose and both live and heat-inactivated immobilized preparations increased as the initial concentration of mercury ions increased in the medium. Maximum biosorption capacity for immobilized live and heat-inactivated fungal mycelia of Phanerochaete chrysosporium was found to be 83.10 and 102.15 mg Hg(II) g(-1), respectively, whereas the amount of Hg(II) ions adsorbed onto the plain carboxymethylcellulose beads was 39.42 mg g(-1). Biosorption equilibria were established in approximately 1 h and the correlation regression coefficients show that the adsorption process can be well defined by a Langmuir equation. Temperature changes between 15 and 45 C did not affect the biosorption capacity. The effect of pH was also investigated and the maximum adsorption of Hg(II) ions onto the carboxymethylcellulose and both live and heat-inactivated immobilized fungal mycelia was observed at pH 6.0. The carboxymethylcellulose-fungus beads could be regenerated using 10 mM HCl, with up to 95% recovery. The biosorbents were used in three biosorption-desorption cycles and no significant loss in the biosorption capacity was observed. (C)2002 Elsevier Science B.V All rights reserved.Öğe Reversible immobilization of urease onto Procion Brown MX-5BR-Ni(II) attached polyamide hollow-fibre membranes(Elsevier Sci Ltd, 2002) Akgol, S.; Yalcinkaya, Y.; Bayramoglu, G.; Denizli, A.; Arıca, M.Y.Urease was immobilized onto Procion Brown MX-5BR attached and Ni(II) incorporated microporous polyarnide hollow-fibre membrane via adsorption. Urease immobilization onto the polyamide hollow-fibre membrane from aqueous solutions containing different amounts of urease at different pH was investigated in a batch system. The maximum urease immobilization capacity of the polyamide hollow-fibre membrane was 78 mg g(-1) fibre. The retained adsorbed enzyme activity was found to be 37%. However, the urease adsorption onto the polyamide fibre resulted in a threefold increase in enzyme stability with time at 50 degreesC. The Km values were 18 and 22 mM for the free and the immobilized enzymes, respectively. The V-max values were 59.7 U mg(-1) for the free and 25.9 U mg(-1) for the immobilized enzyme. The optimum pH (7.0) apparently was shifted 1.0 unit acidic region upon immobilization via adsorption. The optimum reaction temperature for the free and the immobilized enzymes were determined to be 45 and 55 degreesC, respectively. The dye-Ni(II) attached polyamide hollow-fibre membranes could be repeatedly used for the adsorption/desorption of enzyme without any significant loss in adsorption capacity. (C) 2002 Elsevier Science Ltd. All rights reserved.
