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The study aimed at investigating copper, lead, and cadmium removal from both single and mixed metal solutions by Michelia figo (Lour.) Spreng. wood sawdust treated with 0.5 mol l -1 NaOH for four hours. In order to evaluate the effects of each factor and interactions between factors on metal ion biosorption, a 2 3 factorial experimental design was applied. FTIR results showed that the metal ions would bind to the hydroxyl and carboxyl groups of M. figo wood sawdust biomass. The main effects and interactions of three factors pH (3 and 5), initial metal ion concentration (C 0 , 0.157 and 1.574 mmol L -1 ), and dosage of biomass (D, 4 and 10 g L -1 ) at two levels were analyzed. The most significant variable regarding Cu 2+ and Pb 2+ biosorption was initial metal iron concentration. For Cd 2+ , pH was found to be the most significant factor. The maximum removal efficiencies were 94.12 and 100% for Cu 2+ and Cd 2+ , respectively, at conditions of (+ 1, - 1, + 1): pH 5, initial metal concentration 0.157 mmol L -1 and dosage of biomass 10 g L -1 , while 96.39% for Pb 2+ at conditions of (- 1, - 1, + 1): pH 3, initial metal concentration 0.157 mmol L -1 and dosage of biomass 10 g L -1 . There were some interactions between factors: pH*C 0 and C 0 *D for Cu 2+ , pH*C 0 , pH*D and C 0 *D for Pb 2+ , pH*C 0 and C 0 *D for Cd 2+ . Biosorption from a multi metal system showed that the presence of Cu 2+ and Cd 2+ had no significant influence on the Pb 2+ removal, while Pb 2+ in solution significantly decreased the removal efficiencies of the other two metals.

Background: Ceriporia lacerata, a strain of white-rot fungus isolated from the litter of an invasive plant (Solidago canadensis) in China, was little known about its properties and utilization. In this work, the copper(II) biosorption characteristics of formaldehyde inactivated C. lacerata biomass were examined as a function of initial pH, initial copper(II) concentration and contact time, and the adsorptive equilibrium and kinetics were simulated, too., Results: The optimum pH was found to be 6.0 at experimental conditions of initial copper(II) concentration 100 mg/L, biomass dose 2 g/L, contact time 12 h, shaking rate 150 r/min and temperature 25°C. Biosorption equilibrium cost about 1 hour at experimental conditions of pH 6.0, initial copper(II) concentration 100 mg/L, C. lacerata dose 2 g/L, shaking rate 150 r/min and temperature 25°C. At optimum pH 6.0, highest copper(II) biosorption amounts were 6.79 and 7.76 mg/g for initial copper(II) concentration of 100 and 200 mg/L, respectively (with other experimental parameters of C. lacerata dose 2 g/L, shaking rate 150 r/min and temperature 25°C). The pseudo second-order adsorptive model gave the best adjustment for copper(II) biosorption kinetics. The equilibrium data fitted very well to both Langmuir and Freundlich adsorptive isotherm models., Conclusions: Without further acid or alkali treatment for improving adsorption properties, formaldehyde inactivated C. lacerata biomass possesses good biosorption characteristics on copper(II) removal from aqueous solutions.