In this study, a batch sorption method was examined for the sorption, diffusion, and the sorption dynamic of benzene in the pure solvent and the aqueous solution by Polydimethylsiloxane (PDMS) membranes. Liquid-Film Model was developed to explain the mass transfer mechanism of benzene in the aqueous solution by PDMS membranes.
The results, Freundlich and Langmuir were more adapted to describe isotherm adsorption of PDMS in the benzene aqueous solution at 25℃. In dynamic, the diffusion of benzene in PDMS membranes was the persudo-Fickian model of the Non-Fickian diffusion. The diffusion coefficients were gained by curve fitting that was more adaptive for simulation results. In the aqueous solution, the diffusion coefficients of benzene were increased with increasing concentrations and then decreased. This situation may be influenced by hydrate. The solubility coefficients of PDMS membranes were decreased with increasing concentrations and they were very close to linear partition.
Finally, the mass transfer mechanism of benzene by PDMS membranes was appropriately described in the aqueous solution by Liquid-Film Model in this study. It could be a possible method to SPME and waste water reuse technique in the future.
