Curcumin-mediated balsa wood-derived 3D magnetic biochar with dual active sites to activate peroxymonosulfate for PFOA removal.

[Display omitted] • Balsa-derived magnetic Fe 3 C/N@BsB was prepared with curcumin as a mediator. • Fe 3 C/N@BsB had dual active sites to activate PMS for catalytic degradation of PFOA. • Degradation and defluorination efficiencies were 82.9% and 71.4% for PFOA at 4 h. • SO 4 − dominated in the system, with maximum accumulation concentration of 29.6 μM. • In-situ magnetized Fe 3 C/N@BsB with cm-size was convenient for recycling for reuse. Perfluorooctanoic acid (PFOA) is one of the most commonly detected perfluorinated compounds, and now poses a significant threat to animal, plant and human health as an emerging pollutant. Using balsa wood as a natural template and potassium ferrocyanide as a precursor, curcumin-mediated Fe 3 C/N-embedded 3D magnetic biochar (Fe 3 C/N@BsB) was obtained in this study via a facile in-situ pyrolysis method. Featured with dual metallic and non-metallic active centers, Fe 3 C/N@BsB was then utilized for activating peroxymonosulfate (PMS) to degrade PFOA in water. The experimental data indicated that a degradation efficiency of 82.9% and defluorination efficiency of 71.4% were achieved for PFOA at room temperature and pH 3.0. Coexisting 50 mM Cl− in water had no significant impact, while HCO 3 − and HA showed inhibitory effects on PFOA degradation. By the identification and quantification of free radicals, SO 4 − was predominant in the Fe 3 C/N@BsB + PMS system with its maximum accumulation concentration of 29.6 μM. Under the attack of active species, PFOA degradation occurred gradually to produce short-chain by-products for subsequent mineralization. Finally, the recyclability of Fe 3 C/N@BsB and its catalytic degradability in tap water and Yellow River water were also evaluated. This study not only demonstrates the enormous potential of Fe 3 C/N@BsB + PMS system for the removal of emerging PFOA in water, but also provides good theoretical support for the resource utilization of balsa wood. [ABSTRACT FROM AUTHOR]