Removal and recovery of acridine orange from solutions by use of magnetic nanoparticles

Here we report a separation of a cationic dye, acridine orange (AO), by use of magnetic nanoparticles (γ-Fe₂O₃). The particles were showed to capture 98% of the dye within the first 20 min of contact time. The maximum sorption capacity of the magnetic nanoparticles (MNPs) for AO was 59 mg/g. The sorption isotherms fit well with the Freundlich model. The sorption kinetics fits well the pseudo-second-order rate equation model. 60-90% dye recovery was achieved by rotary evaporating the dye bearing nanoparticles in acetone. The nanoparticles were recycled for additional dye removal.