(527a) Treatment of Tetracycline Antibiotics in Water and Wastewater By Hay-Derived Engineered Biochar Catalyst

FeCl₃-activated bermudagrass-derived biochar (FA-BC) was first used for tetracycline (TC) adsorption followed by regeneration with Fenton and persulfate (PS) oxidation. FA-BC exhibited an excellent TC adsorption capacity by surface complexation, hydrogen bonding, and Ï€-Ï€ EDA interaction, while the TC adsorption process was endothermic and spontaneous. Fenton oxidation only exhibited high regeneration efficiency for TC-spent FA-BC at pH 3, while PS oxidation effectively regenerated the TC-spent FA-BC at pH 3-8. Increasing the temperature from 20 to 50 °C enhanced the regeneration performance with Fenton oxidation, while decreasing with PS oxidation. Increasing the temperature from 20 to 50 °C caused the enhancement of TC diffusion, H₂O₂ reaction rate, and PS reaction rate by the factors of 2.20, 1.58, and 4.07. HO· and SO•– 4 radicals mainly participated in the regeneration of TC-spent FA-BC via Fenton and PS oxidation, respectively. Under the optimal conditions, Fenton and PS oxidation effectively regenerated the TC-spent FA-BC with regeneration efficiencies of 99.41% and 99.24%. Adsorption/Fenton oxidation and adsorption/PS oxidation using FA-BC were also applied to treat TC from a real dairy wastewater, achieving the regeneration efficiencies of 94.99% and 93.36%. Thus, this study indicated great potential for application of FA-BC in TC treatment from water and wastewater via cyclic adsorption/Fenton regeneration and cyclic adsorption/PS regeneration.