Adsorption mechanism of polycyclic aromatic hydrocarbons using wood waste-derived biochar

The polycyclic aromatic hydrocarbons (PAHs) have been attracted increasing attentions due to their carcinogenicity and teratogenicity. Adsorption is widely considered one of the most potential technologies for PAHs removal. In this study, we prepared two kinds of oxygen-rich biochar derived from waste wood to investigate the PAHs adsorption performance, and the molecular simulation was used to build the 16 priority PAHs, 23 nitrated PAHs, 9 oxygenated PAHs adsorption model. The surface adsorption performance of oxygen-rich biochar significantly depends on the pyrolysis conditions. The main out-comings demonstrated that the adsorption of naphthalene (C₁₀H₈) molecules first occurred, and the optimal adsorption positions of oxygen-rich biochar strongly adhered to functional groups of carboxyl and hydroxyl. Moreover, benzene ring, -COOH, and -CH₃ of biochar were the main adsorbed functional groups for PAHs adsorption. The oxygen-rich biochar had the targeted-adsorption effect on PAHs removal especially symmetrical PAHs, and the targeted-adsorption mechanism was finally proposed. The research is beneficial to guide the removal of PAHs from polluted water and mitigate the environmental pollution caused by biomass waste mismanagement, simultaneously.