Adsorptive Removal of Methylene Blue from Aqueous Solutions Using Magnetic Fe<sub>3</sub>O<sub>4</sub>@C-dots: Removal and kinetic studies
Mahnaz Ghereghlou, Abbas Ali Esmaeili, Majid Darroudi
Abstract
The Fe3O4@C-dots produced from Elaeagnus Angustifolia, has been applied as an adsorbent for the removal of methylene blue (MB) from aqueous solutions. The prepared Fe3O4@C-dots exhibited a noticeably higher adsorption capacity for MB, reported to be 124.39 mg/g when compared to the results of many other documented references. Furthermore, after evaluating the effects of various parameters on the adsorption capacity of Fe3O4@C-dots, it was discovered that the adsorption capacity increased with the contact time, pH, and MB initial concentration, respectively. Furthermore, the impacts of pH on adsorption were strongly amplified through pHzpc. According to the results, electrostatic interactions, hydrogen bonding, and chemical binding comprise the adsorption mechanism between the MB molecules and adsorbent. The MB adsorption was identified through the kinetic studies to be dominated through the model of pseudo-second-order kinetic. Also, the isotherm analysis showed that the adsorption process is consistent with the Langmuir equations. As the Fe3O4@C-dots were subjected to recycling, no significant changes were observed throughout the adsorption capacity after five regeneration cycles. Considering how the outcomes indicated the capability of magnetic nanoparticles in performing an effective MB removal, we can recommend the high potential of this adsorbent for the clearance of cationic dyes from wastewater.