Magnetically Functionalized Moss Biomass as Biosorbent for Efficient Co²⁺ Ions and Thioflavin T Removal

Microwave synthesized iron oxide nanoparticles and microparticles were used to prepare a magnetically responsive biosorbent from Rhytidiadelphus squarrosus moss for the rapid and efficient removal of Co²⁺ ions and thioflavin T (TT). The biocomposite was extensively characterized using Fourier transformed infrared (FTIR), XRD, SEM, and EDX techniques. The magnetic biocomposite showed very good adsorption properties toward Co²⁺ ions and TT e.g., rapid kinetics, high adsorption capacity (218 μmol g^-1 for Co and 483 μmol g^-1 for TT), fast magnetic separation, and good reusability in four successive adsorption-desorption cycles. Besides the electrostatic attraction between the oxygen functional moieties of the biomass surface and both Co²⁺ and TT ions, synergistic interaction with the -FeOH groups of iron oxides also participates in adsorption. The obtained results indicate that the magnetically responsive biocomposite can be a suitable, easily separable, and recyclable biosorbent for water purification.