Simultaneous biosorption of cadmium (II) and lead (II) ions by pretreated biomass of Phanerochaete chrysosporium

The article extends the study on the treatment of heavy metal wastewater by considering the competitive biosorption of two metal ions together, Cd (II) and Pb (II), by Phanerochaete chrysosporium, a filamentous fungus, under optimum biosorption conditions determined for each metal ion. The effects of the presence of one metal ion on the biosorption of the other metal ion were investigated in terms of equilibrium isotherm and adsorption yield. Experimental results indicated that the uptake capacity and adsorption yield of one metal ion were reduced by the presence of the other metal ion. In addition, comparisons between biosorption of Pb (II) ions and Cd (II) ions by the biomass of P. chrysosporium in the binary solution could lead to the conclusion that biosorption of Pb (II) ions was preferential to that of Cd (II) ions. In the single-ion situation, biosorption of Cd (II) ions and Pb (II) ions had the optimum adsorption conditions in common, which were the solution pH 4.5, temperature 27degreesC. The maximum uptake obtained at initial concentration of Cd (II) ions 50 mg l(-1), could reach 15.2 mg g(-1), for Pb (II) ions it could reach 12.34 mg g(-1). Both the adsorption equilibrium data fitted the Freundlich model well. Moreover, the uptake of Cd (II) ions had a less sensitive dependence on temperature than that of Pb (II) ions. (C) 2003 Elsevier B.V. All rights reserved.