Magnetic cross-linked chitosan modified with ethylenediamine and beta-cyclodextrin for removal of phenolic compounds

摘要

The Fe/CLCh-EDA/beta-CD adsorbent was prepared using cross-linked chitosan (CLCh) containing magnetic iron oxide and modified with ethylenediamine (EDA) and beta-cyclodextrin (beta-CD). This adsorbent was characterized by infrared (IR) spectroscopy, X-ray diffraction (XRD), Raman spectroscopy, Atomic Absorption Spectroscopy (EAA), Scanning Electron Microscopy (SEM), zeta potential and elemental analysis (CHN). The effect of adsorbent dosage, contact time, pH, kinetics, temperature and adsorption thermodynamics were evaluated by the removal of phenol (PHE), p-nitrophenol (PNP) and p-cresol (PCS). The Fe/CLCh-EDA/beta-CD presented a maximum adsorption capacity for PHE of 243.08 mg g(-1), PNP of 274.24 mg g(-1) and PCS of 298.35 mg g(-1) (120 min) at pH 6 and 25 degrees C. The Fe/CLCh-EDA/beta-CD can be easily removed from the aqueous solution by magnetization due to its magnetic properties. Thermodynamic parameters indicate that adsorption is spontaneous and exothermic. This adsorbent showed satisfactory results when applied in the treatment of pulp and paper industry effluent that naturally contains phenol, p-nitrophenol and p-cresol and fortified river water samples.