Removal of a dye from an aqueous solution by the fungus Aspergillus niger

Biosorption is becoming a promising alternative to replace or supplement th e present dye removal processes from dye wastewater. In this study, removal of a dye, Basic Blue 9, from an aqueous solution by biosorption on the dea d fungal biomass Aspergillus niger was studied. The effective pretreatment method for increasing the biosorption capacity of A. niger was investigated . Autoclaving was found to effectively enhance the biosorption capacity of A. niger to 18.54 mg/g compared with 1.17 mg/g of living cells for Basic Bl ue 9. Batch pH, kinetic and isotherm studies were conducted to evaluate the biosorption capacity of the pretreated (dead) biomass. The initial pH of t he dye solution strongly affected the biosorption capacity and rate. The ef fective initial pH was between 4 and 6. The equilibrium time varied with th e initial pH of the dye solution and was set at 30 h because no significant dye removals occurred after that time of contact The Lagergren and Ho et a l. models can be used to describe the kinetics of Basic Blue 9 biosorption on A, niger successfully for different initial pH values, except for pH 4. At initial pH 4,biosorption of Basic Blue 9 fitted the Langmuir equation we ll; at initial pH 10, the Langmuir and Freundlich isotherm models both fitt ed biosorption well. The results of this study indicated that fungal biomas s of A. niger can be used for removing Basic Blue 9 from an aqueous solutio n.