Removal of phenolic pollutants from aqueous solutions by a simple magnetic separation

摘要

The removal efficiencies of phenol, 2-chlorophenol (2-CPh), and 4-chlorophenol (4-CPh) from aqueous solution with magnetic chitosan nanoparticles were investigated in this work. Chitosan-coated magnetite nanoparticles were successfully synthesized, characterizated, and applied as an effective magnetic biosorbent for the removal of phenol, 2-CPh, and 4-CPh from aqueous solutions. The characterization of synthesized magnetic chitosan nanoparticles was performed by Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, dynamic light scattering, vibrating sample magnetometry analyses, and thermogravimetric analysis. Adsorption characteristics of phenolic compounds from aqueous solution on to magnetic chitosan have been studied and results indicated that the adsorption capacities were affected by initial pH values, initial concentration of adsorbates, dosage of adsorbent, and contact time. The adsorption of adsorbates followed with the pseudo-second-order reaction and equilibrium experiments were well fitted with the Freundlich isotherm model. Furthermore, it was found that the magnetic biosorbent can be regenerated and reused for five repeated cycles for the removal of phenol, 2-CPh, and 4-CPh and avoided secondary pollution of biosorbent to water.