Adsorption of perflourooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) on polyaniline nanotubes

Perflourooctane sulfonate (PFOS) and perflourooctanoate (PFOA) in aqueous environment have attracted considerable attention. The adsorption of PFOS and PFOA on polyaniline nanotubes (PANTs) from water was studied. The results of adsorption kinetics showed that the adsorption equilibrium of PFOS and PFOA on PANTs could be achieved in 48h and the experimental data could be fitted well by pseudo-second-order model, reflecting of a chemical controlled adsorption. The adsorption isotherms of PFOS and PFOA on PANTs fitted well to the Langmuir model, suggesting the adsorption behavior was monolayer adsorption and the maximum adsorption amount were 1651 mg/g and 1100 mg/g for PFOS and PFOA on polyaniline emeraldine salt nanotubes (PASNTs), respectively. Thermodynamic results indicated that the adsorption process of PFOS and PFOA by PANTs was endothermic. The electrostatic attraction played an important role in the adsorption of PFOS and PFOA on PANTs and other forces such as hydrophobic interaction might be also involved. (C) 2015 Elsevier B.V. All rights reserved.