Jalil Kermannezhad, Hassan Torabipoodeh, Elham Ghanbari-Adivi, Babak Shahinejad,
Volume 30, Issue 3 (10-2026)
Conventional methods for desalination of water and wastewater are usually not economically viable for providing the water required for agricultural production due to high energy consumption and equipment costs. This study aimed to evaluate the efficiency of magnetic nanobiochar produced from sugarcane bagasse to remove sodium ions from agricultural wastewater under the influence of a magnetic field. Non-nanoactive, nanoactive, and magnetic nanoactive adsorbents were produced using a pyrolysis process in an electric furnace at 600 °C, chemical activation with potassium hydroxide, and magnetization with a combination of hexahydrate ferric chloride and heptahydrate ferric sulfate. The results showed that the highest removal rates of chloride ions (44.6%) and sodium ions (58.3%) were obtained in the magnetically activated nano-biochar under the influence of a magnetic field of 0.5 Tesla, for an activator-to-biochar ratio of 3, a microwave power of 400 W, and an activation time of 10 minutes. Surface analyses including FT-IR spectroscopy and scanning electron microscopy (SEM) confirmed that the hydroxyl, carboxyl, and carbonyl functional groups on the surface of the adsorbent play a key role in the adsorption of sodium and chloride ions. It was also observed that the application of a magnetic field improved the orientation of the ions towards the adsorbent and weakened the hydrogen bonds in water, which led to an increase in the efficiency of the adsorption process. This study shows that magnetic nano-biochar, under a magnetic field, could be an economical and sustainable solution for reducing the salinity of agricultural wastewater.
