Biosorption of Zn2+ and Pb2+ from aqueous solutions using native and microwave treated Flammulina velutipes stipe

Native stipe (NS) and microwave treated stipe (MTS) of Flammulina velutipes were utilized for the biosorption of Zn2+ and Pb2+ ions from aqueous solution. The effects of pH, contact time, and initial concentration on the biosorption were studied for each metal separately. The desired pH of aqueous solution was found to be 6.0 for the removal of Zn2+ ions and 5.0 for the removal of Pb2+ ions. The percent removal of both metals was found to increase with the increase in contact time; biosorption equilibrium was established in about 60 min. The maximum biosorption of Zn2+ and Pb2+ ions from single component systems can be successfully described by Langmuir and Freundlich models; the biosorption kinetics can be accurately described by a second-order kinetic model. The present data from these studies confirms that the native and microwave treated forms of Flammulina velutipes stipe have the potential to be used for the biosorption of Zn2+ and Pb2+ ions from aqueous solution. The metal biosorption capacities of NS for Zn2+ and Pb2+ were 58.14 and 151.51 mg g−1, respectively, while the biosorption capacities of MTS for the both metals were 95.24 and 172.41 mg g−1, respectively.