RESUMO
This study aims at the transformation of the waste lignocellulosic biomass, Simarouba glauca seed shell obtained from biofuel industries, into a value-added adsorbent for the removal of dyes from aqueous media. The basic dye direct red (DR) 12B was adsorbed using chemically (ZnCl2) and thermally activated Simarouba seed shell carbon (ZASRC and SRC, respectively). Dye removal in batch mode was studied by evaluating adsorbent dosage, contact time, pH, adsorption isotherm and kinetics. Enhanced adsorption of DR12B was attained within 80 min at pH 5 with the maximal adsorption capacity (Q0) of 17.48 and 64.94 mg g-1, for SRC and ZASRC, respectively. Further, the dye removal followed Freundlich isotherm model and pseudo second-order kinetics. The mean-free energy of adsorption demonstrated that dye adsorption onto ZASRC occurs through ion-exchange. Thus, ZASRC can be safely and easily applied for the removal of direct red 12B from aqueous solutions.