Adsorptive removal of aromatic amine from aqueous solutions using carbon black as adsorbent

This is the first work to report the removal of an aromatic amine (o-tolidine) from aqueous solutions using a carbon black (Vulcan XC 72 R) as adsorbent. The adsorbent material was characterized using Raman spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, thermogravimetric analysis, and pH at the point of zero charge. The effects of contact time, pH, and initial concentration on o-tolidine adsorption were evaluated. Avrami kinetic model best described the adsorption process. Weber-Morris model showed that the aromatic amine adsorption mechanism is controlled by intraparticle and film diffusion on Vulcan XC 72 R. Temkin isotherm model described equilibrium results, with a maximum adsorption capacity of 64.00 mg g−1 at 25 °C. Thus, the results highlight the applicability of Vulcan XC 72 R as an effective and low-cost adsorbent to decontaminate effluents containing o-tolidine.