Application of mixed fungal biomass for effective reactive dye removal from textile effluents

Abstract

Reactive Remazol Blue (RB) removal properties of growing Aspergillus versicolor and Rhizopus arrhizus were investigated as a function of initial pH (3-7) and dye concentration (50800 mg/L) in low-cost molasses medium. Decolorization activity of mixed (A. versicolor and R. arrhizus together) culture in the absence and presence of (0.5 and 1 mM) dodecyl trimethyl ammonium bromide (DTAB) was examined at optimal conditions. A. versicolor and R. arrhizus exhibited maximum decolorization at pH 6 as 89.4% and at pH 3 as 69.23% at 100 mg/L dye concentration in six days. The decolorization of A. versicolor depended on fungal growth but R. arrhizus was related with its positively charged surface. Decolorization by both fungi decreased with increasing dye concentration up to 800 mg/L. The mixed culture decolorized 86.5% and 100% of 100 mg/L RB in the absence and presence of 0.5 mM DTAB in three days. Decolorization activities by R. arrhizus (10.06%), A. versicolor (15.79%), the mixed culture (26.59%), the mixed culture with 0.5 mM (61.33%) and 1 mM DTAB (73.19%) were compared at 800 mg/L RB in three days. The results of this study show that the systems contained mixed culture with surfactant that decolorized high level of reactive dye concentration effectively.