Biosorption of Remazol Black B dye (Azo dye) by the growing Aspergillus flavus

In the present study, an attempt was made for the removal of Remazol Black B dye (azo dye) by using Aspergillus Flavus during its growth. Biosorption of the azo dye by growing fungi was investigated in batch reactors as a function of initial concentration of dye (25-1000 mg/L), inoculum concentration (5-20%), and pH (2.5-6.5). The total biomass concentration decreased from 6.3 g/L to 1.44 g/L by increasing the dye concentration from 0 to 1000 mg/L. The dye uptake increased from 4.37 to 233 mg/g of dried biomass by increasing initial concentration of dye from 25 to 1000 mg/L. The nearly complete removal of dye was found at initial concentration upto 250 mg/L and at pH 4.5 which was used as working pH value for removal of dye in all the batch studies. The removal of Chemical Oxygen Demand (COD) was found to be 90% at 100 mg/L initial concentration of dye. The experiments were also performed with wastewater from textile industry with an aim to examine the potential of fungal biomass for the removal of dyes from wastewater under actual field conditions. The maximum dye removal was obtained at 30° C temperature (87%) in presence of 1 % glucose concentration (89%) and 10 % inoculum concentration (91%) after 96 hours from textile wastewater. The surface of the biosorbent before and after the sorption of the dye was examined by FTIR and SEM analysis.