Plant mediated synthesis of sustainable magnetite nano adsorbent for efficient cadmium (II) removal from aqueous media

The need to eliminate hazardous heavy metals, such as cadmium (Cd (II)), has become increasingly evident. In this study, magnetite nanoparticles (Fe₃O₄-NPs) supported on teff straw and modified with a green approach were synthesized, characterized, and tested for their ability to remove Cd (II) ions. The characterization of the teff straw-supported Fe₃O₄-NPs was carried out using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermo gravimetric analysis (TGA), and scanning electron microscopy (SEM). Both FT-IR and TGA analysis confirmed effective surface functionalization of the Fe₃O₄-NPs. The XRD analysis confirmed the presence of magnetite in the synthesized teff straw-supported Fe₃O₄-NPs, with an average crystalline size of 18.83 nm. SEM analysis revealed that the Fe₃O₄-NPs were nearly spherical, with an average particle size of 23.85 nm. Adsorption studies were conducted to examine the adsorption of Cd(II) on the teff straw-supported magnetite nanoparticles and the influence of various adsorption parameters. The findings indicated that the solution pH had the greatest impact on the removal of Cd(II) ions. Optimal experimental conditions were found to be a pH of 6, contact time of 45 min, adsorbate concentration of 40 mg/L, and adsorbent amount of 1 g. Under these conditions, a maximum removal efficiency of 98.04% for Cd(II) was achieved. FT-IR analysis also showed that surface functional groups such as C = C, -OH, and C-C on the newly produced Fe₃O₄-NPs contributed to the enhanced removal of Cd(II) ions from the aqueous solution. The Langmuir model best described the adsorption isotherm data, with a maximum adsorption capacity of 101.01 mg/g. Therefore, teff straw-supported Fe₃O₄-NPs are an efficient and promising adsorbent for Cd(II) ions removal.