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Öğe Biosorption of Hg(II) and Cd(II) from aqueous solutions: Comparison of biosorptive capacity of alginate and immobilized live and heat inactivated Phanerochaete chrysosporium(Elsevier Sci Ltd, 2002) Kacar, Y.; Arpa, C.; Tan, S.; Denizli, A.; Genc, O.; Arica, M.Y.Basidiospores of P. chryosporium were immobilized into Ca-alginate beads via entrapment, and the beads incubated for vegetation at 30 degreesC for 5 days. The alginate beads and both entrapped live and heat inactivated fungal mycelia of Phanerochaete chryosporium were used for the removal of Hg(II) and Cd(II) ions from aqueous solution in the concentrations range of 30-500 mg l (-1). The biosorption of Hg(II) and Cd(II) ions by the biosorbents increased as the initial concentration of Hg(II) and Cd(11) ions increased in the medium. A biosorption equilibrium was established in about 1 h and the adsorbed heavy metal ions did not change further with time. The effect of pH was also investigated and the maximum biosorption of Hg(11) and Cd(II) ions on all the tested biosorbents were obtained between pH 5.0 and 6.0. Temperature over the range 15-45 degreesC had no significant effect on the biosorption capacity. The equilibrium was well described by Langmuir and Freundlich biosorption isotherms. The alginate-fungus beads could be regenerated using 10 mM HCl, up to 97% recovery. The biosorbents were reused in three biosorption-desorption cycles with negligible decrease in biosorption capacity. (C) 2002 Elsevier Science Ltd. All rights reserved.Öğe Ca-alginate as a support for Pb(II) and Zn(II) biosorption with immobilized Phanerochaete chrysosporium(Elsevier Sci Ltd, 2003) Arica, M.Y.; Arpa, C.; Ergene, A.; Bayramoglu, G.; Genç, O.The basidio spores of Phanerochaete chryosporium were immobilized in alginate gel beads, and the immobilized spore containing alginate beads were incubated for the growth of fungus. The biosorption of Pb2+ and Zn2+ ions on alginate beads and both immobilized live and heat inactivated fungus was studied from artificial waste waters in the concentrations range of 30-600 mg 1(-1). The surface charge density of the biosorbents varied with the pH of the medium and the maximum biosorption of heavy metal ions on the biosorbents was obtained between pH 5.0 and 6.0. The biosorption of Pb2+ and Zn2+ on the biosorbents increased as the initial concentration of Pb2+ and Zn2+ ions increased in the medium. Biosorption equilibrium was established about 1 h, the adsorbed heavy metal ions did not significantly change further with time. The maximum biosorption capacity (q(m)) of alginate beads and both immobilized live and heat inactivated fungus were 230, 282 and 355 mg for Pb2+ and 30, 37 and 48 mg for Zn per gram of dry biosorbents, respectively. The experimental biosorption equilibrium data for Pb2+, and Zn2+ ions were in good agreement with those calculated by Langmuir model. The affinity order of heavy metal ions was Pb2+ > Zn2+, (C) 2003 Elsevier Science Ltd. All rights reserved.Öğe Comparative biosorption of mercuric ions from aquatic systems by immobilized live and heat-inactivated Trametes versicolor and Pleurotus sajur-caju(Elsevier Sci Ltd, 2003) Arica, M.Y.; Arpa, C.; Kaya, B.; Bektas, S.; Denizli, A.; Genc, O.Trametes versicolor and Pleurotus sajur-caju mycelia immobilized in Ca-alginate beads were used for the removal of mercuric ions from aqueous solutions. The sorption of Hg(II) ions by alginate beads and both immobilized live and heat-killed fungal mycelia of T versicolor and P. sajur-caju was studied in the concentration range of 0.150-3.00 mmol dm(-3). The biosorption of Hg(II) increased as the initial concentration of Hg(II) ions increased in the medium. Maximum biosorption capacities for plain alginate beads were 0.144+/-0.005 mmol Hg(II)/g; for immobilized live and heat-killed fungal mycelia of T versicolor were 0.171+/-0.007 mmol Hg(II)/g and 0.383+/-0.012 mmol Hg(II)/g respectively; whereas for live and heat-killed P. sajur-caju, the values were 0.450+/-0.014 mmol Hg(II)/g and 0.660+/-0.019 mmol Hg(II)/g respectively. Biosorption equilibrium was established in about 1 h and the equilibrium adsorption was well described by Langmuir and Freundlich adsorption isotherms. Between 15 and 45 degreesC the biosorption capacity was not affected and maximum adsorption was observed between pH 4.0 and 6.0. The alginate-fungus beads could be regenerated using 10 mmol dm(-3) HCl solution, with up to 97% recovery. The biosorbents were reused in five biosorption-desorption cycles without a significant loss in biosorption capacity. Heat-killed T versicolor and P. sajur-caju removed 73% and 81% of the Hg(II) ions, respectively, from synthetic wastewater samples. (C) 2003 Elsevier Science Ltd. All rights reserved.Öğe Selective recovery of mercury by Procion Brown MX 5BR immobilized poly(hydroxyethylmethacrylate/chitosan) composite membranes(Elsevier Science Bv, 2002) Genç, O.; Arpa, C.; Bayramoğlu, G.; Arıca, M.Y.; Bektaş, S.Metal chelating membranes have advantages as adsorbents in comparison to conventional microspheres or beads because they are not compressible and they considerably eliminate internal diffusion limitations. The aim of this communication was to explore in detail the performance of Procion Brown MX 5BR immobilized poly(hydroxyethylmethacrylate/chitosan) composite membranes, (also called interpenetrating network, IPN, membranes) for removal of three toxic heavy metal ions, namely, Cd(II), Pb(II) and Hg(II) from aquatic systems. The composite membranes were characterized by elemental analysis, scanning electron microscopy and Fourier Transform Infrared (FTIR) spectroscopy. The incorporated amount of the Procion Brown NIX 5BR was calculated. as 0.036 mumol/cm(2) from the nitrogen and sulphur stoichiometry. The adsorption capacity for selected heavy metal ions from aqueous media containing different amounts of these ions (30-400 mg/L) and at different pH values (2.0-6.0) was investigated. Adsorption capacity of the membranes increased with time during the first 45 min and then levelled off toward the equilibrium adsorption. The maximum amounts of heavy metal ions adsorbed were found as 18.5, 22.7 and 68.8 mg/g for Cd(H), Pb(H) and Hg(H), respectively. Competitive adsorption of the metal ions was also studied. When the metal ions competed, the adsorbed amounts were found as 1.8 mg Cd(II)/g, 2.2 mg Pb(II)/g and 52.6 mg Hg(II)/g. Under competitive conditions, the system showed a very high selectivity for Hg(H) ions. The membrane can be regenerated by washing with a solution of nitric acid (0.01 M). The desorption ratio achieved was as high as 95%. These membranes are suitable for repeated use for more than five adsorption/desorption cycles without any considerable loss in adsorption capacity. (C) 2002 Elsevier Science B.V. All rights reserved.
