Biosorption of Cr(III) and Cr(VI) by Newly Isolated White Rot Fungi: Batch and Column Studies

Abstract

The present study was planned to evaluate the heavy metals uptake potential of newly isolated white rot fungi from metals contaminated sites. Three white rot fungi viz., Pleutrotus sajorcajor, Ganoderma lucidum and Agaricus bitorquis were selected for biosorption of Cr(III) and Cr(VI) studies. The optimum pH for maximum uptake of Cr(III) and Cr(VI) by native/immobilized Pleurotus sajor-caju, Agaricus bitorquis and Ganoderma lucidum was found to be 5 and 2, respectively. Increase in biomass concentration in a fixed volume of solution (100 mL) at constant pH 5, initial metal concentration (100 mg/L) and temperature (30 ºC) reduced the metal sorption capacity of biomass. Biosorption of both metal ions increased with concentration from 25 to 200 mg/L. Langmuir adsorption isotherm model and pseudo second order kinetic model fitted well to metal biosorption data. Equilibrium for metal uptake was reached within 2 h of contact. Metal uptake process was found dependent on temperature. The pseudo second order kinetic model fitted well to experimental data of column study as it had higher value of correlation coefficient (R²). Sulphuric acid was found as the best eluent for metal recovery from dead fungal biomass.