Sorption of phenol from aqueous solution by novel magnetic polysulfone microcapsules containing Cyanex 923

This paper describes the sorption of phenol from aqueous solution by using novel magnetic polysulfone (PSF) microcapsules containing Fe3O4 nanoparticles and mixture of trialkyl-phosphine oxides (Cyanex 923) (Cyanex 923/Fe3O4@PSF microcapsules). The preparation of the Cyanex 923/Fe3O4@PSF microcapsules was based on the phase-inversion technique. The prepared microcapsules were characterized by using Fourier Transform Infrared Spectroscopy (FT-IR), Thermal Gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX) and Vibrating Sample Magnetometer (VSM). Fe3O4 nanoparticles in the microcapsules provided easier separation via application of external magnetic field. The experiments indicated that phenol could be removed from aqueous solution at a pH range between 3 and 9. The Cyanex 923/Fe3O4@PSF microcapsules prepared with dispersed phase containing 3.35% of Cyanex 923 (by wt.) provided the highest removal. The sorption reached an equilibrium in 120 min and it obeyed the pseudo-second order kinetic model. The non-linear Chi-square (χ2) statistical test showed that Langmuir isotherm model better represented the sorption data in comparison to Freundlich and Redlich-Peterson models. The Langmuir sorption capacity (Qo) and sorption constant (b) were 0.664 mmol/g and 0.855 L/mmol, respectively. The regenerated microcapsules could be used five times with no change in their sorption capacity and magnetic separability.