Biosorption of Textile Dye by Aspergillus lentulus Pellets: Process Optimization and Cyclic Removal in Aerated Bioreactor

The present study was conducted to maximize the biosorption of dye by utilizing the native (untreated) pellets of Aspergillus lentulus. The native (55.0 mg/g) and heat-treated (56.7 mg/g) pellets showed excellent dye biosorption capacity which declined upon alginate immobilization (27.2 mg/g). Fourier transform infrared and EDX spectra revealed that phosphate and -CH3 groups are important in determining the biosorption capacity of the pretreated fungal biomass. The operating conditions of the aerated fed batch reactor were optimized and 90 % removal of Acid Blue 120 in 12 h was achieved after five biosorption-desorption cycles. At the end of the fifth cycle, 508.57 mg/L dye could be removed in 60 h with the removal rate of 8.48 mg/L/h. Further, the potential utilization of fungal biomass for the treatment of complex effluent was validated by studying the dye removal from unprocessed textile effluent wherein 58.0 % dye was removed within 4 h of contact.