Adsorption step in the biological degradation of a textile dye

This research documents the removal of the dye Gris Lanaset G from aqueous solutions by fungal pellets. Adsorption of the dye by dead biomass pellets of Trametes versicolor was determined and compared with dye removal by enzy matic degradation. Six kinetic equations were fitted to the experimental ad sorption data obtained. The results indicate that kinetics such as the Elov ich equation, which considers that the rate-controlling step is the diffusi on of the dye molecules, show the best fit. Nonlinear Langmuir and Freundli ch equations were also fitted into the adsorption data, and it can be concl uded that the adsorption equilibrium can be interpreted by the Langmuir iso therm. Adsorption plays an important role in the process of the elimination of color from textile wastewater, although not all of the elimination is d ue to this physical process when the microorganism is active. The removal o f color (around 90%) with active microorganisms is greater than that obtain ed with the adsorption process.