Biosorption of Pb(II) by Nonliving Lichen Biomass of Cladonia rangiformis Hoffm

Environmental contamination by toxic metals is a serious problem due to their extreme toxicity towards aquatic life and humans. Biosorption is an alternative technology to conventional processes for the removal of metals. Biosorption of Pb(II) ions on the lichen biomass of Cladonia rangiformis Hoffm. is presented in this research. Batch experiments were conducted to study the biosorption properties of lichen biomass for Pb(II) and the effects of initial metal ion concentration, initial pH, biosorbent concentration, stirring speed and contact time on biosorption efficiency. The optimum pH value was found out 5.0 which was the native pH value of solution. Concentrations ranging from 30 to 150 mg/L Pb(II) were studied and the biosorptive removal efficiency of the metal ions was obtained as 99.5%. The experimental biosorption data were fitted to the Freundlich adsorption model and the regression constants were determined at 15oC. The results indicated that the biomass of Cladonia rangiformis is a suitable biosorbent for removing Pb(II) from aqueous solutions.