Adsorption of toluene into commercial organoclay in liquid phase: Kinetics, equilibrium and thermodynamics

Organoclays are usually used as sorbents to reduce the spread of organic compounds and to remove them at contaminated sites. This study investigated the liquid‐phase adsorption of toluene on organoclay (Spectrogel® Type C) of Brazilian company SpectroChem. In spite of not having a large amount of pores, this organoclay is a low‐cost, effective adsorbent. Regarding the pH investigations, considerable effects of pH on the adsorption process were not observed. In the kinetics studies, it was observed that the process comes into equilibrium after 1 h with rates of about 90 % toluene removal. The experimental kinetic data were best fitted by a mass transfer in external film model. For the equilibrium study, the best fit was by the MSAM model at 288.15 K, the Dubinin‐Radushkevitch model at 298.15 K, and the Sips model at 308.15 K. Further, the thermodynamic parameters showed that toluene adsorption on organoclay Spectrogel‐C is an endothermic process. For tests of regeneration, ethanol was the eluent, which proved more promising9369981008CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESsem informaçã