Screening and selection of indigenous metal tolerant fungal isolates for heavy metal removal

Abstract

Heavy metal removal efficiency of indigenously present metal tolerant fungal isolates obtained from a scrap dumpsite was assessed in this study. Four fungal isolates were selected based on their ability to grow in multi-metal supplemented media. Minimum inhibition concentrations of these four isolates were determined against individual metals; lead (II) (50 400 mgL?1), cadmium (II) (50 400 mgL?1), arsenic (III) (10 100 mgL?1) and mercury (II) (10 100 mgL?1). Their ability to remove metals from synthetic aqueous medium was tested and the heavy metal fungi combination which showed the highest removal efficiency was selected. Live biomass of the selected isolate dispensed in lead solution with concentrations of 50 mgL?1, 100 mgL?1 and 150 mgL?1 showed a removal of 92.27%, 92.73% and 89.36% respectively at the end of the 40th h. Scanning Electron Microscopy with Electron Dispersive X-ray (SEM-EDX) of the treated biomass confirmed the biosorptive ability of the isolate for lead when compared with the control biomass. Fourier Transforms Infra-red (FTIR) Spectroscopy showed the probable involvement of amide, carboxylic acid, hydroxyl and isocyanate groups in the adsorption of lead from the synthetic metal solution. 2017 Elsevier B.V.