Selective removal of 2,4-dichlorophenol and 2,4,6-trichlorophenol in aqueous solutions by polyaniline-modified magnetic nanoparticles using high-performance liquid chromatography–UV detection

摘要

The aim of this work was to develop simple, efficient, and environmental friendly adsorbent, polyaniline (PANI)-modified magnetic nanoparticles (Fe3O4@PANI) for the removal of 2,4-dichlorophenol and 2,4,6-trichlorophenol from wastewater. Magnetic nanoparticles were synthesized by co-precipitation method and coated with PANI through oxidative polymerization of aniline monomers. The morphology, elemental composition, and crystallinity of (Fe3O4@PANI) were determined using scanning electron microscopy, energy dispersion X-ray, X-ray diffraction spectroscopy, and Fourier-transform infrared spectroscopy for functional group analysis, respectively. The parameters effecting the adsorption efficiency such as pH, temperature, contact time, adsorbent dosage, and initial concentration of 2,4-dichlorophenol and 2,4,6-trichlorophenol were studied. The experimental adsorption results were evaluated by different isotherms, and the Freundlich isotherm model was found to best fit the data. Three kinetics models were applied to the data and the pseudo-second-order kinetic model was found leading the kinetics of adsorption process. Thermodynamics evaluation of the adsorption parameters showed that the adsorption is exothermic and spontaneous at low temperature. This research elucidated that (Fe3O4@PANI) is efficient, low cost, and environmental friendly adsorbent to remove to 2,4-dichlorophenol and 2,4,6-trichlorophenol from wastewater.