The study investigates the removal of lignin from paper mill wastewater using Fe3O4 magnetic nanoparticles (MNPs) as an adsorbent, revealing high adsorption efficiency at low pH values and optimal contact time of 10 minutes. Characterization of the nanoparticles indicates an average size of 10 nm, and the removal efficiency is affected by pH, with maximum adsorption occurring at pH 2.5. Additionally, desorption studies show that acetonitrile is the most effective solvent for regenerating the nanoparticles, achieving over 80% desorption efficiency under optimal conditions.