Fe3O4/sugarcane bagasse magnetic composite: A low-cost and green adsorbent for enhanced adsorption of Rhodamine B from aqueous solutions

In this study, we have designed and synthesized an eco-friendly Fe3O4/sugarcane bagasse magnetic composite (Fe3O4/SCB). We investigated its application for efficiently removing Rhodamine B (RhB) from textile wastewater, a significant step towards addressing the environmental issue of textile dye pollution. The composite, made from sugarcane bagasse (SCB), a secondary product from the sugarcane industry, proved an effective adsorbent. The composite Fe3O4/SCB was characterized by PXRD, FT-IR, FE-SEM, VSM, BET N2 adsorption-desorption, and pHpzc. Results from batch adsorption studies show that the removal of RhB was 93.6 ± 1.16 % using a composite dose of 1 g/L, a RhB concentration of 10 mg/L, a contact period of 60 min, and a solution pH of 3 at 323 K of solution temperature. The kinetic studies indicate that the pseudo-second-order model most accurately describes the adsorption. Meanwhile, the equilibrium data is well-represented by the Freundlich isotherm. Further, the analysis of thermodynamic results, such as the changes in ∆Go, ∆So, and ΔHo, revealed that the adsorption was spontaneous, feasible, and endothermic. The adsorption mechanism involved chemisorption and physisorption, with significant roles played by electrostatic interactions and hydrogen bonding. Desorption studies identified 0.5 M NaOH as an effective desorbing agent, and the composite demonstrated excellent reusability over four adsorption-desorption cycles. Overall, the Fe3O4/SCB, with its easy preparation, abundance, cost-effectiveness, efficiency, and eco-friendly nature, presents a promising solution for effectively removing toxic RhB from aqueous solutions, inspiring further research and potential real-world applications. [Display omitted] •Synthesis of Fe3O4/SCB magnetic composite for efficient removal of Rhodamine B.•Achieved 93.6 ± 1.16 % removal efficiency of Rhodamine B using 1 g/L Fe3O4/SCB.•Pseudo-second-order kinetics and Freundlich isotherm describe the adsorption process.•Both chemisorption and physisorption are involved in the adsorption process.•Excellent composite reusability over four adsorption-desorption cycles.