Synthesis of biohybrid magnetic chitosan-polyvinyl alcohol/MgO nanocomposite blend for remazol brilliant blue R dye adsorption: solo and collective parametric optimization

Abstract

In this work, a new quadruple nanocomposite of chitosan/polyvinyl alcohol/magnesium oxide/Fe3O4 (Chit-PVA/MgO/Fe3O4) was prepared for the adsorption of remazol brilliant blue R (RBBR) dye in batch process. Several advanced analytical techniques including BET, XRD, FTIR, SEM–EDX, potentiometric titrations, and pHpzc were performed for characterizing of the synthesized nanocomposite (Chit-PVA/MgO/Fe3O4). A multi-step experimental design was derived from response surface methodology (RSM) for optimizing the factors affecting RBBR dye adsorption, namely A: dose (0.02–0.1 g), B: pH (4–10), C: temperature (30–60 °C), and time D: (10–60 min). The obtained kinetic data and adsorption isotherm for the studied Chit-PVA/MgO/Fe3O4-RBBR system followed pseudo-second-order and Langmuir isotherm model, respectively. The maximum adsorption capacity of Chit-PVA/MgO/Fe3O4 toward RBBR was found to be 163.7 mg/g. The adsorption mechanism of RBBR dye by Chit-PVA/MgO/Fe3O4 possibly comprises an electrostatic interaction, hydrogen bonding, n-π interactions, and Yoshida H-bonding. This work reveals that Chit-PVA/MgO/Fe3O4 nanocomposite is an efficient and recoverable biohybrid adsorbent with a great ability to remove organic dye from an aqueous environment.