Green Synthesis of Fe3O4-Crataegus tanacetifolia (Lam.) Biochar Magnetic Nanocomposites for Adsorption of Naproxen

In this study, naproxen (NPX), one of the emerging contaminants was removed by green synthesizing Fe₃O₄ coated magnetic biochar nanocomposites (Ct-BMNCs) synthesized from Crataegus tanacetifolia Lam. (Ct) wastes. The characteristics of Ct-BMNCs was examined by x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray (EDX), Fourier transform infrared spectroscopy (FTIR), thermogravimetry-differential thermal analysis (TGA-DTA), dynamic light scattering (DLS), zetasizer, Brunauer-Emmett-Teller (BET) UV–Vis spectroscopy, and pH point of zero charge (pH_pzc). With batch adsorption tests, the effects of pH (4–11), amount of adsorbent (2.5–80 g L⁻¹), time, and initial concentration (3.125–200 mg L⁻¹), and thermodynamic analysis was performed. Also, kinetic and isotherm models and error functions were used. Accordingly, the pH_pzc and average surface charge were 5.68 and +11.7 mV, respectively. Moreover, the reaction was exothermic, and the most suitable models were Pseudo-second-order and Freundlich (R²:0.999). Also, q_max was 30.12 mgNPX/gCt-BMNCs. Accordingly, Ct-BMNCs are quite effective in removing NPX.