Optimization, kinetic and thermodynamic studies for removal of Brilliant Red (X-3B) using Tannin gel

Optimization, kinetic and thermodynamic studies for adsorption of Brilliant Red (BR) on biomass Tannin gel (TG) have been reported. The adsorption efficiency was justified by modulating dye concentration, contact time, adsorbent dosage, pH, and concentration of interfering substances (CI−, NO3−, SO42−, and CO32−). At pH 2.0 the adsorption–desorption equilibrium time was availed after 90 min and maximum %DR was found 94% at 1.2 g/L adsorbent dose. The adsorption phenomenon displays better resemblance with Langmuir isotherm with maximum monolayer adsorption capacity of 45.07 mg/g in comparison with Freundlich, Temkin and Dubinin-RadushKevich (DR) isotherms. The adsorption process of BR dye onto Tannin gel was found to be spontaneous due to negative value of Gibbs free energy (−4.18 kJ/mol at 28 °C) and as the enthalpy change was positive the adsorption process was endothermic in nature.

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