Decolorization of textile dyes by white rot fungi

Reactive azo and vat dyes are largely employed on cellulosic fibers like cotton. Due to their low biodegradability, they cause serious environmental pollution. Wastewater from textile industries constitute a threat to the environment in large parts of the world. Here, the decolorization rate of Reactive Red 141, Reaktif Red 120, Reaktif Blue 171, Reaktif Blue 198, Reaktif Green 19 and Acid Blue 74 by Trametes versicolor, Funalia trogii and Phanerochaete chrysosporium pellets was studied. The effects of various operational parameters, namely dye concentration (50?200 mg/l), pH (3?10), temperature (10?40oC), amount of pellets and agitation (0-200 rpm) on decolorization were investigated. Decolorization was measured spectrophotometrically. In 2 h, the most decolorized dyes were that of Acid Blue 74 which removed about % 89 of initial color, followed by Reactive Blue 198 with % 85 decolorization. Decolorization studies were carried out using free pellets, immobilized fungal cells on actived carbon and pinewood and also fungal cells entrapped in alginate beads in repeated batch mode. Decolorization rate of free pellets was higher than immobilized cells except that cells entrapped in alginate beads. The fungal pellets could be used for several times during repeated batch mode. Adsorption of the dyes on fungi except Phanerochaete chrysosporium was insignificant. Glucose and molasses positively affected the dye decolorization of T. versicolor. Molasses and copper addition resulted in high and stable decolorization efficiency. Trametes versicolor and Funalia trogii pellets efficiently decolorized artificial dyestuff containing mixtures of Reaktif Blue 171, Reaktif Blue 198, Reaktif Green 19 and Acid Blue 74 especially in first cycle of repeated batch mode.