Preparation of magnesium Ferrite-Doped magnetic biochar using potassium ferrate and seawater mineral at low temperature for removal of cationic pollutants

Magnetic biochar has captured a great interest for remediation of environment as an easily separable carbonous adsorbent. Herein, a highly adsorptive magnetic biochar was manufactured through seawater mineral and K2FeO4 co-promoted pyrolysis of jackfruit peel at 300 °C for removal of different cationic pollutants, and characterized by element analysis, FTIR, SEM-EDS, XRD, XPS and so on. MgFe2O4 was generated without external base and a 19.42 emu/g saturation magnetization was achieved. Simultaneously, iron oxides and oxygen containing groups were introduced. The magnetic biochar exhibited 61.30 mg/g, 129.61 mg/g, and 1238.30 mg/g adsorption capacities for Cu2+, methylene blue (MB), and malachite green (MG) at 25 °C, respectively, and remarkably surpassed the corresponding pristine biochar. The adsorption of MB and MG was mainly realized by electrostatic interaction, hydrogen bonding, complexation, and π-π electron-donor-acceptor interaction, and that of Cu2+ was attributed to electrostatic interaction, hydrogen bonding, and complexation.