Fabrication and characterization of polymer based magnetic dialdehyde carboxymethyl cellulose/cysteine nanocomposites for methylene blue removal

Magnetic dialdehyde carboxymethyl cellulose cysteine nanocomposite (Fe3O4/DCMC/Cys) was successfully synthesized by an effective procedure without any toxic monomer and crosslinking agent and used as a sorbent for the removal of cationic dye methylene blue (MB) from aqueous solution. Scanning electron microscopy with energy-dispersive X-ray spectrometry, Fourier transform infrared spectroscopy, X-ray diffraction, vibrating-sample magnetometry, and thermogravimetric analysis techniques were used to characterize the nanocomposite. The performance of Fe3O4/DCMC/Cys for MB removal was studied in a batch process, using different parameters such as sorbent dosage, contact time, initial dye concentration and pH. The pseudo-first-order, pseudo-second-order and intra-particle diffusion kinetic models were applied to test the experimental data and were found to follow closely the pseudo-second-order kinetic model. Adsorption data were well described by the Langmuir model. Dye adsorption equilibrium was rapidly attained after 60 min of contact time, and the Langmuir capacity of the composite was 370.37 mg g(-1). Thermodynamic parameters also demonstrated that the dye adsorption was spontaneous and endothermic in nature. Fe3O4/DCMC/Cys nanocomposite with the magnetic property of Fe3O4 and the strong adsorption performance of cysteine amino acid was shown to be a promising and effective adsorbent for the treatment of MB contaminated water.