Biosorption of Hg(II) and Cd(II) from aqueous solutions:: Comparison of biosorptive capacity of alginate and immobilized live and heat inactivated Phanerochaete chrysosporium

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.