title: Biosorption of Hg2+, Cd2+, and Zn2+ by Ca-alginate and immobilized wood-rotting fungus Funalia trogii.
abstract: Funalia trogii biomass was immobilized in Ca-alginate gel beads. The live and heat 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 degrees C 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 F. 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.
authors.affiliation: Biochemical Processing and Biomaterial Research Laboratory, Faculty of Science, Kirikkale University, 71450 Yahsihan, Kirikkale, Turkey.
authors.forename: M Yakup
authors.initials: MY
authors.lastname: Arica
authors.forename: Gülay
authors.initials: G
authors.lastname: Bayramoglu
authors.forename: Meltem
authors.initials: M
authors.lastname: Yilmaz
authors.forename: Sema
authors.initials: S
authors.lastname: Bektaş
authors.forename: Omer
authors.initials: O
authors.lastname: Genç
mesh_terms: D000327:Adsorption; D000464:Alginates / Q000737:chemistry*; D002104:Cadmium / Q000737:chemistry*; D005658:Fungi / Q000378:metabolism*; D020723:Glucuronic Acid / Q000737:chemistry*; D006603:Hexuronic Acids / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008628:Mercury / Q000737:chemistry*; D008956:Models, Chemical; D012996:Solutions; D016060:Sorption Detoxification / Q000379:methods; D013696:Temperature; D015032:Zinc / Q000737:chemistry*
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D012996:Solutions; D002104:Cadmium; D020723:Glucuronic Acid; D008628:Mercury; D015032:Zinc