Adsorptive decontamination of synthetic wastewater containing crystal violet dye by employing Terminalia arjuna sawdust waste

In the present work, Terminalia arjuna sawdust (TASd) has been employed as an effective adsorbent for the elimination of crystal violet (CV) dye from synthetic wastewater. The adsorbent was characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. Batch adsorption experiments have been conducted to optimize different factors affecting adsorption. The findings were observed to be best followed by Freundlich adsorption isotherm with 0.9964 as the correlation coefficient. The equilibrium was attained in 120 min and the highest adsorption capacity was observed to be 45.99 mg g−1 at the optimum adsorbent dose and pH of 0.4 g L−1 and 7, respectively. Kinetic experiments revealed that the removing process of CV by TASd obeys pseudo-first-order kinetic model and the k1 value was found to be 0.013 min−1. The thermodynamic investigation indicates that the process of adsorption of CV by TASd is feasible, endothermic and associated with an increase of entropy. Desorption analysis shows that the used adsorbent could be better regenerated in sodium hydroxide. © 2018 Elsevier B.V.