Activation of peroxymonosulfate by food waste digestate derived biochar for sulfamethoxazole degradation: Performance and mechanism

Digested derived biochar-based peroxymonosulfate (PMS) systems are promising for degrading antibiotics from water. Identifying the reactive sites on biochar and understanding the relationship between biochar structure and reactive oxygen species (ROS) generation are crucial for design and application of biochar-based catalysts. Herein, food waste digested was selected for the biochar preparation (FWDB). In a FWDB/PMS system, sulfamethoxazole (SMX) was degraded primarily by non-radicals rather than free radicals based on the contribution calculation. Correlation of catalytic sites on FWDB surface to ROS production was revealed. Defects exhibited a strong positive correlation with 1O2 contribution. The C = O, C-O, pyrrolic N, pyridinic N contents showed a moderate positive correlation with 1O2 contribution. Besides, the designed granular FWDB was loaded in a continuous flow reactor, achieving efficient and stable removal of contaminants from secondary effluent in a municipal wastewater plant. Findings from this study might offer novel perspectives for the development and design of biochar catalysts, promoting the actual application of biochar in a complicated aqueous matrix.