Magnetic biochar composite: Facile synthesis, characterization, and application for heavy metal removal

In this work, we demonstrate a facile fabrication method for the synthesis of magnetic biochar composite (MBC) by using low-cost pine bark waste and CoFe2O4. Sorption characteristics of the as-fabricated MBC for the removal of both Pb(II) and Cd(II) ions were studied in batch conditions. The physical and chemical structures of the composite were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy, and X-ray diffraction studies. The effect of pH, the initial metal ion concentration, and the contact time on adsorption of Pb(II) and Cd(II) onto MBC were investigated. The MBC exhibited good sorption performance over the initial pH range 4–6. The kinetic data were studied by applying two sorption kinetic models, pseudo-first- and pseudo-second-order equations. Different sorption isotherm models including two-parameter and three-parameter models were applied to the experimental data. The adsorption kinetics was well represented by the pseudo-second-order rate equation, and the adsorption isotherms were better fitted by the Langmuir equation. The combination of various fascinating features including simple magnetic separation, low-cost, environmental friendly nature, and good sorption performance enables MBC to be used in industrial applications specifically in the field of water treatment.