Optimised activation of bentonite for toluene adsorption

摘要

Acid-activation of bentonite was optimised to prepare an effective adsorbent of toluene. The activated bentonite was obtained with a specific surface area of 195 m~2/g, a pore volume of about 0.46 cm~3/g and a most frequent pore size of 62 A. Compared to the raw bentonite, the adsorption of toluene onto acid-activated bentonite was increased from 66 mg/g to 197 mg/g. Vapor-solid adsorption isotherms of toluene were measured at 120 ℃, 140 ℃, 160 ℃ and 182 ℃ using an inverse gas chromatography. The experimental data were correlated with different adsorption isotherm models such as Langmuir, Freundlich, Langmuir-Freundlich and Toth models. Only the Langmuir-Freundlich equation provided good fit to the experimental data.