Environ Exp Biol (2019) 17: 97–105

Biosorption of hexavalent chromium by Aspergillus fumigatus S101 isolated from a coal mining environment

Abstract

In this study attempts were made to isolate a Cr-binding fungal population from coal mine soils of Jharkhand, India. A total of 15 fungal isolates belonging to the genera Aspergillus, Penicillium and Fusarium were obtained from the soils. Among them, Aspergillus fumigatus S101 was found to tolerate up to 5 mM Cr(VI) and showed maximum metal uptake capacity of 1.868 mM g^–1 biomass in presence of 0.5 mM Cr(VI) within 48 h. The sorption capacity was standardized following Langmuir and Freundlich absorption isotherm models that followed pseudo-second-order kinetics. The biosorption ability of A. fumigatus S101 was maximum at pH 5 and at 30 °C. There was a decrease in metal uptake capacity with increase in biomass, but with the increase in Cr(VI) concentration metal uptake capacity increased. The sorption capacity increased in presence of metal ions such as Fe(III) and Cu(II) showing complete removal of 0.5 mM Cr(VI) within 36 h. Treatment of biomass with Tween 80 resulted in maximum sorption accounting for 100% removal of 0.5 mM Cr(VI) in 24 h. The results suggested that the mycelial mass of A. fumigatus (S101) is capable of efficient removal of Cr(VI) from aqueous solution.