Process Optimization and Adsorptive Mechanism for Reactive Blue 19 Dye by Magnetic Crosslinked Chitosan/MgO/Fe3O4 Biocomposite

Abstract A new biocomposite magnetic crosslinked glutaraldehyde-chitosan/MgO/Fe3O4 (CTS-GL/MgO/Fe3O4) adsorbent was prepared and applied for the removal of reactive blue 19 (RB 19) synthetic textile dye. The prepared CTS-GL/MgO/Fe3O4 was subjected to the several instrumental characterizations such as XRD, FTIR, SEM-EDX, pH-potentiometric titration, and pHpzc analyses. The influence of the input adsorption parameters such as A: CTS-GL/MgO/Fe3O4 dosage, B: initial solution pH, C: process temperature, and D: contact time on RB 19 removal efficiency was statistically optimized using Box-Behnken design (BBD). The analysis of variance (ANOVA) indicates the presence of five significant statistical interactions between input adsorption parameters i.e. (AB, AC, AD, BC, and BD). The adsorption kinetic and equilibrium study reveals a good to the pseudo-second-order model, and multilayer adsorption as proven by Freundlich isotherm model, respectively. The maximum adsorption capacity of CTS-GL/MgO/Fe3O4 towards RB19 was found to be 193.2 mg/g at 45 ºC. This work highlights the development of feasible and recoverable magnetic biocompsite adsorbent with desirable adsorption capacity towards textile dyes with good separation ability by using an external magnetic field.