Effective removal of crystal violet in the aqueous solution using magnetic composites originated from sugarcane bagasse

This study targeted to generating composites comprised of sugarcane bagasse (SCB) and magnetic particles (MPs) under a facile and low-cost approach. Moreover, the adsorption performance of composites, treated SCB, and MPs for crystal violet (CV) was evaluated. Cellulose fibers were firstly isolated from SCB with a two-step process and employed as a matrix material to randomly adhere MPs via an in situ chemical co-precipitation method at room temperature. The properties of the composite were determined through analysis methods such as X-ray diffractometer (XRD), scanning electron microscopy with energy-dispersive X-ray analysis (EDX/SEM), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), vibrating sample magnetometer (VSM), and Brunauer–Emmett–Teller (BET). Magnetization, surface area, and pore diameter of magnetic fiber composite were 11.1 emu/g, 20 m²/g, and 0.002 cm³/g, respectively. The characteristic peaks of cellulose and MPs were found in XRD results, whereas the Fe content in composite was 27.52%. FTIR spectra also exposed the characteristic functional groups of MPs and treated SCB. Additionally, the CV removal using composites was evaluated with the adsorption efficiency and capacity of 72.09% and 77.22 mg/g, respectively, at pH 7, an adsorbent dose of 2 g/L, a CV concentration of 150 mg/L within 30 min. The adsorption process corresponded to the Sips model and the pseudo-second-order kinetic model. Besides, the mechanism of CV adsorption was primarily characterized by heterogeneous adsorption on the surface and physical sorption. In short, the obtained composite was a promising adsorbent for treating the dye-containing wastewater.