Removal of erythrosine dye from aqueous solutions using magnetic chitosan with erythrosine as imprinted molecules

摘要

A novel, chitosan coating on the surface of magnetite (Fe3O4) (erythrosine-imprinted magnetic chitosan (EIMC)) was successfully synthesized using erythrosine (ER) as a template for adsorption and the removal of ER from aqueous solutions. Characterization of the obtained EIMC was achieved by FTIR spectra, SEM micrographs, and TGA analysis. Batch adsorption experiments of EIMC and non-imprinted magnetic chitosan (NIMC) were performed to investigate the adsorption conditions. The results showed that the maximum adsorption capacity for EIMC and NIMC was observed at pH 6 and temperature 40 degrees C. Equilibrium adsorption was achieved within 3 h. Adsorption process could be well described by Freundlich adsorption isotherms. Thermodynamic parameters namely Delta G degrees, Delta H degrees, and Delta S degrees of the ER adsorption process were calculated. The negative values of Gibbs free energy of adsorption (Delta G degrees) indicated the spontaneity of the adsorption of ER dye on the EIMC and NIMC. Desorption of ER from EIMC and NIMC could be done rapidly using 0.1 M NaOH solution and the beads could be used again to remove ER. Results show that imprinting technique increases the removal amount of ER dye from aqueous solutions.