Enhancement of Tetracycline Hydrochloride Degradation via Peroxymonosulfate Activation by KOH‐Modified Wheat Straw Biochar

ABSTRACT The widespread application of tetracycline hydrochloride (TCH) has induced severe aquatic contamination, demanding efficient remediation strategies. This study synthesized wheat straw‐derived biochar at 300°C (BC‐300), 500°C (BC‐500), and 700°C (BC‐700), with BC‐500 exhibiting optimal adsorption capacity. Potassium hydroxide modification of BC‐500 yielded KBC‐500, characterized via scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), and Raman spectroscopy (Raman) to assess structural and chemical properties. In peroxymonosulfate (PMS) activation experiments, KBC‐500 outperformed BC‐500, achieving 91.18% TCH degradation efficiency (initial concentration: 10 mg/L). Mechanistic investigations via radical quenching and electron paramagnetic resonance (EPR) confirmed sulfate (SO 4 ·− ) and hydroxyl (·OH) radicals as primary reactive species. Critical operational parameters included PMS concentration and KBC‐500 dosage, while pH exerted negligible influence. Elevated chloride (Cl − ) and bicarbonate (HCO 3 − ) concentrations enhanced degradation efficiency by 1.47% and 2.64%, respectively, likely due to secondary radical generation. Temperature‐dependent kinetics revealed accelerated TCH removal at higher temperatures. This work advances the valorization of agricultural waste (wheat straw) and establishes a cost‐effective advanced oxidation process system for antibiotic‐contaminated water remediation, emphasizing the synergistic roles of adsorption and radical‐driven oxidation.