Biosorption of Cadmium(II) and Lead(II) from Aqueous Solutions by Fruiting Body Wastes of Fungus Flammulina velutipes

The biosorption of Cd(2+) and Pb(2+) by fruiting body wastes of macro-fungi Flammulina velutipes was studied. The factors affecting absorption including pH initial metal concentration, biosorbent dosages and mutual competitive biosorption of both metal ions were focused. The sorption of Cd(2+) and Pb(2+) was increased with pH value from 2-6 and maximum biosorption was at pH6. The quantity of Cd(2+) and Pb(2+) adsorbed increased with the initial concentration metal ions and both metal removal gradually increased with biosorbent dosage. There existed mutual competitive biosorption between Cd(2+) and Pb(2+) when they were in the same solution. The Langmuir isotherm model fitted both metal ions sorption data well in the experiment and the calculated maximum sorption capacity of Cd(2+) and Pb(2+) by F. velutipes was 6.84 mg.g(-1) dry biomass with R(2) of 0.9775 and 13.61 mg.g(-1) dry biomass with R(2) of 0.9661, respectively. Pseudo-first order equation fitted for adsorption data of Cd(2+) with R(2) of 0.9504, while pseudo-second order equation more fitted for adsorption data of Pb(2+) with R(2) of 0.9917.