Bio Fabrication of MgO Decorated Spinel Magnetite Nanoparticles for Efficient Removal of AO Dye: Isotherm, Kinetic, and Thermodynamic Study

This work describes a simple technique for producing bio-synthesized Magnesium oxide modified magnetite nanoparticles (MgO@MNPs) for the removal of AO dyes using Almond (Terminalia catappa) leaf extract (ALE). ALE is employed as capping, stabilizing, and reducing agent. This work presents an investigation of the removal of dye using nanoparticles. In this study synthesized nanoparticles get characterized using various analytical techniques such as UV–Vis, XRD, FT-IR, TGA, SEM, EDX, and VSM. The adsorption conditions were tuned for the maximal removal of AO dyes by altering many physicochemical factors, including pH (8.0), initial concentration of AO dye (30 mg/L), MgO@MNPs dosage (8 mg), contact time (8 min), and reaction temperature (298 K). The results of isotherm study indicated that Langmuir model adequately described the adsorption process and effectively removed the dye with a high adsorption capacity (q_max) 526.31 mg/g. Additionally, the study evaluated the kinetic and thermodynamic aspects of the adsorption process. Moreover, the adsorption process was found to be spontaneous, exothermic, and followed a pseudo-second-order kinetic model. HCl was found to be an effective desorbing agent in the desorption experiment. The adsorbent could be reused for seven cycles effectively with at least 96% removal of AO dye. The comparison table provided in this work further highlights the effectiveness of the present study. Overall, this study offers a promising approach for the efficient removal of AO dye from wastewater, with potential for practical applications in the field of wastewater treatment.

Graphical Abstract