Adsorption of Aniline from Aqueous Solution by KSF Montmorillonite

In the present paper, the adsorption characteristics of aniline onto KSF montmorillonite from aqueous solution were investigated. Experiments were conducted at various pH values, temperatures, ionic strength and surfactant concentrations. Pseudo-first-order, pseudo-second-order and intraparticle diffusion models were adopted to investigate the rate parameters, and the pseudo-second-order equation was proved to be able to successfully predict whole process. Optimal adsorption pH was determined at 3.6. Among the selected models (linear, Langmuir, Freundlich, DR (Dubinin-Radusckevich) models), linear and DR models were found to be better fit the experimental data, which revealed the physisorption nature of the adsorption process. Meanwhile, with the increase of reaction temperatures, the adsorption capacity decreased. The results of the calculated thermodynamic parameters demonstrated that the adsorption was an exothermic, spontaneous and unfavorable process.