Metal-free nitrogen and sulfur binary-doped cellulose-based biochar for efficient suppression of priority organic pollutants and environmental application.

[Display omitted] • Efficient conversion of cellulose to biochar through pyrolysis was demonstrated. • Effects of various conditions of temperature and non-metal modification were assessed. • Conditions inhibitory to polycyclic aromatic hydrocarbons (PAHs) were determined. • Heteroatom modification was found to effectively remove PAHs from biochar. Biochar production from cellulose biomass is an alternative solution in the search for clean and renewable biofuel. However, the rational design of cellulose biochar (CLBC) for polycyclic aromatic hydrocarbons (PAHs) reduction by integrating pyrolysis process parameters and introducing heteroatoms as inhibitors remains to be studied. Therefore, exogenous heteroatoms (N, B, S, SB, NB, and NS) were used to modify CLBC for the first time. CLBC300 pyrolyzed at 300 °C in a CO 2 atmosphere achieved the highest concentrations of PAHs (4982 ± 271 ng g−1), compared with that of CLBC700 (3615 ± 71 ng g−1) formed in a N 2 atmosphere without heteroatom doping. The results showed that binary nitrogen- and sulfur-doped CLBC exhibited remarkable PAH-removal performance of 99 % with the lowest toxic equivalency (TEQ) value of 9 ng g−1. Overall, this study presents novel insights into the development of a heteroatom-based modification approach for reducing CLBC-borne PAHs and creating value-added products from cellulose biomass. [ABSTRACT FROM AUTHOR]