Biosorption and Bioaccumulation of Copper and Lead by Heavy Metal-Resistant Fungal Isolates

Abstract

Microorganisms play an important role in the bioremediation of heavy metal-contaminated wastewater and soil. In this research, isolation of heavy metal-resistant fungi was carried out from wastewater-treated soil samples of Hudiara drain, Lahore. The purpose of the present investigation was to observe fungal absorption behavior toward heavy metal. The optimum pH and temperature conditions for heavy metal removal were determined for highly tolerant isolates of Aspergillus spp. along with the initial metal concentration and contact time. Biosorption capacity of A. flavus and A. niger was checked against Cu(II) and Pb(II), respectively. The optimal pH was 8–9 for A. flavus and 4–5.4 for A. niger, whereas optimal temperature was 26 and 37 °C, respectively. Moreover, the biosorption capacity of A. flavus was 20.75–93.65 mg g−1 for Cu(II) with initial concentration 200–1400 ppm. On the other hand, biosorption capacity of A. niger for Pb(II) ranged from 3.25 to 172.25 mg g−1 with the same range of initial metal concentration. It was also found that equilibrium was maintained after maximum adsorption. The adsorption data were then fitted to Langmuir model with a coefficient of determination >0.90. The knowledge of the present study will be helpful for further research on the bioremediation of polluted soil.