Abstract

• The fungi are the most common and efficient group of the heavy metal resistant microbial family which have potential for metal biosorption study. In this research work, ten fungi were isolated from solid mining waste and soil sample. The isolated fungi were screened for their heavy metals tolerance to different concentrations (0-20 mM) of Cr6+, Cu2+, Cd2+, and Ni2+ solutions. Minimum inhibitory concentrations (MICs) for (Cr6+, Cu2+, Cd2+, and Ni2+) were also determined by the agar diffusion method. Most of the isolates were tolerant of the metals. Among all fungal strains, isolated from solid mining waste, Aspergillus niger was the highest resistant to Cu2+ ion up to 20 mM. Thus A. niger exhibiting great tolerance to metal ion was used for biosorption study. The optimum parameters for biosorption (pH, contact time, initial metal concentration and adsorbent dose) were studied. The maximum removal efficiency of copper was observed around 60.27 % at pH 4.5 with 0.1g adsorbent dose for 5h. Metal sorbed adsorbents were characterized by FT IR and SEM analysis. In FT IR spectra, changes in spectral data of biomass were observed after absorption of Cu (II) by A.niger. Scanning electron microscopy indicated that the morphology of the biomass considerably changed after metal sorption. It could be concluded that A.niger possessed significant heavy metal tolerance and biosorption potential against Cu2+ions.