Removal of zirconium from aqueous solution by Ganoderma lucidum: biosorption and bioremediation studies

Abstract

The development of nuclear science and technology, especially the wide applications of nuclear power, poses a major environmental threat that needs to be remediated. The present study reports the ability of live and dead mycelia of Ganoderma lucidum to remove Zr(IV) ions from aqueous solutions in batch system. The biosorption characteristics of G. lucidum for Zr(IV) ions were evaluated as a function of medium pH, biomass dosage, contact time, initial zirconium concentration and temperature. Maximum zirconium uptake (142.5 mg/g) was observed at pH 3.5. Increase in biomass dosage did not increase the biosorption capacity. The zirconium biosorption was rapid, with more than 74% of the total biosorption taking place within 15 min and equilibrium was attained after 240 min. The Zr(IV) biosorption process could be well defined by the Langmuir isotherm. The kinetic data fitted the pseudo-second-order kinetic model. A dilute solution of sulphuric acid (0.1 N) was found to be the most effective desorbing agent with a metal recovery up to 91.82%. Bioremediation of zirconium with live mycelia of G. lucidum was also investigated as a function of biomass dosage, initial zirconium concentration, contact time and temperature. The results revealed that all the studied parameters affected the bioremediation process. Fourier-Transform Infra-red Spectroscopy analysis of biomass showed the involvement of –OH, –NH₂ and –COOH as major functional groups involved in the sequestering of zirconium ions from aqueous solution. The study suggests that G. lucidum biomass could be used for treating water containing zirconium ions.

Keywords:

• Biosorption
• Bioremediation
• Ganoderma lucidum
• Immobilization
• Kinetics