Biochar loaded with CoFe2O4 enhances the formation of high-valent Fe(IV) and Co(IV) and oxygen vacancy in the peracetic acid activation system for enhanced antibiotic degradation

作者：Li, Shuo; Liu, Yingnan; Zheng, Heshan; Niu, Junfeng; Leong, Yoong Kit; Lee, Duu-Jong; Chang, Jo-Shu^*

来源：Bioresource Technology, 2023, 387: 129536.

DOI：10.1016/j.biortech.2023.129536

• Biochar composite
• Peracetic acid
• Thermal activation
• High-valent metal ions
• Singlet oxygen

Corn straw and sludge-derived biochar composite (BC) loaded with CoFe2O4 was successfully prepared to activate peracetic acid (PAA) for efficient degradation of tetracycline hydrochloride (TCH). Within 60 s, 96 % TCH removal efficiency was achieved through a non-free radical degradation pathway, primarily driven by singlet oxygen (O-1(2)). The mechanism involves the electron-rich groups on the biochar surface, which facilitate the cleavage of the PAA O-O bond to generate .O-2(-)/O-1(2) and provide electrons to induce the formation of high-valent Fe(IV) and Co(IV). The oxygen vacancies on the surface of the CoFe2O4-loaded biochar composite (CFB-2) contribute partially to O-1(2) production through their transformation into a metastable intermediate with dis -solved oxygen. Moreover, elevated temperatures further enhance PAA activation by CFB-2, leading to increased reactive oxygen species (ROS) production through PAA decomposition, thereby promoting TCH removal. This study offers new insights into the catalysis of metal-loaded biochar for efficient TCH degradation via non-free radical generation.