Research Progress on the Preparation of Iron-Based Magnetic Biochar and Its Adsorption Performance for Heavy Metals in Wastewater

• • Iron-based magnetic biochar (MBC-Fe) achieves high adsorption capacities for heavy metals; for instance, Pb(II) adsorption capacity reaches up to 200 mg/g (Zhao et al., 2019), enabling efficient removal from wastewater with easy magnetic separation. • • The introduction of iron increases specific surface area and pore volume by up to 30% compared to pristine biochar, enhancing active sites for metal binding and improving adsorption kinetics. • • MBC-Fe exhibits fast adsorption kinetics, reaching equilibrium within 2 hours for Cd(II) removal (Tan et al., 2017), which is critical for industrial continuous-flow treatment systems. • • Magnetic separation efficiency of MBC-Fe exceeds 95% under external magnetic field, allowing >90% recovery and reuse over multiple cycles, reducing operational costs in wastewater treatment.