Anionic congo red dye removal from aqueous medium using Turkey tail (Trametes versicolor) fungal biomass: adsorption kinetics, isotherms, thermodynamics, reusability, and characterization

Turkey tail (Trametes versicolor), cheap fungal biomass (TTFB), was used for the adsorption of CR from aqueous medium. Batch studies conducted to study the effect of pH (2.0-10.0), agitation speed (50-400 rpm), contact time (0-180 min), adsorbate concentration (300 and 500 mg/L), and temperature (303-333 K). TTFB characterized by FTIR, BET, SEM, and pH(pzc). The maximum monolayer adsorption capacities of CR on TTFB were 318.1, 368.4, 394.8, and 415.7 mg/g at 303, 313, 323, and 333 K, respectively. The adsorption of CR was pH-dependent and maximum adsorption attained at pH 2.0 at all temperatures. Adsorption kinetic data evaluated by using the PFO and PSO non-linear equations. The kinetic data perfectly illustrated by the PSO model withR(2)> 9935. Langmuir, Freundlich, D-R, and Temkin nonlinear isotherms applied for the experimental data, and it observed that the experimental data well fitted and found to be in good agreement with the Langmuir model (R-2> 0.9961) as compared with another three models. The values of Delta G degrees(-3.4159 to -6.1149 kJ/mol), Delta H degrees(23.2 kJ/mol), and Delta S degrees(0.088 kJ/mol K) revealed that the adsorption process was spontaneous, feasible and endothermic (Delta G degrees < 0, Delta S degrees > 0, and Delta H degrees > 0). The regeneration experiments indicated that the TTFB could successfully retain CR, even after five consecutive adsorption-desorption cycles. The binding of CR onto the TTFB surface was through electrostatic interactions. Therefore, TTFB considered as highly recyclable and efficient adsorbent material for CR as it can easily separate from the aqueous phase.