Effective Bioremediation of Cd, Cr, and Pb in Tannery Effluent Using Aspergillus fumigatus and Aspergillus terreus : Synergistic Effects of Using the Two Strains Together

Large volume of wastewater is generated by tannery industry. The wastewater generated in the form of effluent contains heavy metals such as cadmium, chromium, lead, zinc, manganese, and other pollutants. The heavy metals are toxic chemicals released into the water bodies and contaminate soil and other related parts of the environment. In the study, tannery effluents were collected from Challawa industrial area, Kano, Nigeria. Physicochemical parameters were determined in which pH, DO, BOD, TSS, electric conductivity and turbidity were assessed, while the heavy metal such as Cd, Cr, and Pb were all found above permitted limits, which indicate the levels of contamination by toxic materials in the tannery effluent. Bioremediation process involves use of microbes to convert harmful chemical substances into harmless. In the present study, two tolerant fungal isolates Aspergillus fumigatus and Aspergillus terreus were obtained from the enriched effluent which were further tested individually and together in the form of a consortium. The highest biosorptions of metal ions were obtained as 93.28% of Cd, 89.41% of Cr, and 97.13% of Pb at 144 h, indicative of the bioremediation potential of the fungal isolates individually and in the form of a consortium.