Fast aniline and nitrobenzene remediation from water on magnetized and nonmagnetized Douglas fir biochar.

Abstract Magnetic biochar (MBC) was prepared by the dispersion of α-Fe 2 O 3 and Fe 3 O 4 particles on high surface area (663 m 2 /g) Douglas fir biochar (BC). The BC was impregnated with FeCl 3 and pyrolyzed at 600 °C under N 2 to produce (494 m 2 /g) MBC. Both BC and MBC biochars were used for removal of aniline and nitrobenzene from water. MBC and its precursor BC were characterized using scanning electron microscopy (SEM), energy dispersive X-ray analysis (SEM-EDX), transmission electron microscopy (TEM), surface area analysis (Brunauer-Emmett-Teller isotherm) (S BET ), point of zero charge (PZC), X-ray powder diffraction (XDR), elemental analysis, and X-ray photoelectron spectroscopy (XPS). Batch sorption studies were carried out from pH 2–12 and both aniline and nitrobenzene adsorption on MBC and BC remained high and unchanged over the entire pH range. Sorption was evaluated using the Langmuir and Freundlich isotherm models. Langmuir adsorption capacities on BC and MBC (pH 7, 25 °C) were 360 mg/g and 338 mg/g for aniline and 193 mg/g and 178 mg/g for nitrobenzene, respectively.