Effective adsorptive removal of reactive dyes by magnetic chitosan nanoparticles: Kinetic, isothermal studies and response surface methodology

In the present study, magnetic chitosan (MC) was synthesized, characterized, and used as an efficient adsorbent for the removal of Reactive Red 141 (RR-141) and Reactive Yellow 14 (RY-14) dyes. Synthesized magnetic chitosan nanoparticles were used for characterization with the help of scanning electron microscope (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), and X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The effect of the pH, concentration of pollutants, and adsorbent dosage on the amount of adsorption was studied. Under optimum conditions, the removal rate of RR-141 and RY-14 was 99.5 and 92.7%, respectively. The maximum adsorption capacities were obtained 98.8 and 89.7 mg/g for the RR141 and RY-14, respectively. The results from isotherm models showed that the adsorption of dyes on magnetic chitosan nanocomposite correlated well with Freundlich model, whereas the kinetics studies revealed that the adsorption process was fitted by pseudo-first-order for both dyes. Results of the reusability tests confirmed the magnetic chitosan (MC) nanoparticles could be used for several times. Based on the experimental results obtained, the MC has adequate potential for the treatment of water contaminated with anionic dyes. (C) 2020 Published by Elsevier B.V.