Effective adsorbent for the removal of methylene blue using natural serpentine/magnetite nanocomposites: Isotherm and...

The natural serpentine from Skardu, Pakistan, has been incorporated with magnetite (Fe₃O₄) to form a nanocomposite using a chemical co-precipitation method for the removal of methylene blue (MB) dye. Various techniques such as Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray spectroscopy (EDX), Fourier Transform Infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), and Vibrating Sample Magnetometer (VSM) have been employed for the characterization. It was found that the composite exhibits sheet-like morphologies, Mg- and Si-rich surfaces, a surface area of 20.8 m²/g, and magnetic properties. The adsorption study showed that the Freundlich isotherm and pseudo-second-order kinetics best described the process with the nanocomposite achieving a 98 % MB removal efficiency, outperforming the pure serpentine. These results highlight the potential of serpentine/Fe₃O₄ nanocomposite as an effective, cost-efficient adsorbent for wastewater treatment applications.