Biosorption of Turquoise Blue dye from aqueous solution by dried fungal biomass (Trichoderma harzianum) - kinetic, isotherm and thermodynamic studies

The removal of Turquoise Blue dye by the dried biomass of Trichoderma harzianum has been investigated through equilibrium, kinetics and thermodynamic studies. The parameters such as the effect of dye concentration, temperature, contact time, adsorbent dosage and pH are studied in batch experiments. A maximum decolourization of 94% was achieved at pH 4 at the temperature of 37 degrees C, a dye concentration of 50 mg/L and 0.4 g/L biosorbent dose. In addition, characterization of biosorbent was performed by scanning electron microscopy and Fourier transform infrared (FTIR) analysis. The FTIR spectral analyses showed the involvement of hydroxyl, carbonyl and carboxyl groups in biosorption process. These results indicated that T. harzianum could be used as a novel biosorbent for the removal of Turquoise Blue dye from aqueous solution. The experimental biosorption equilibrium data for Turquoise Blue dye are processed with various isotherm like Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models. For the present system, high correlation coefficients favour the Freundlich isotherm model. Similarly, pseudo-second-order model seems to best fitted from the interpretation of biosorption kinetics data. The biosorption was found to be endothermic in nature. To our knowledge, this is the first report to confirm the effective use of T. harzianum biosorbent to remove Turquoise Blue dye from industrial effluents in wastewater treatment process.