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[Display omitted] • SDZ was degraded in 5 min with the removal rate remaining at 78.2 % after 4 cycles. • Defect structures of the catalyst act as the active site to promote ROS production. • SDZ degradation involves synergistic effects of free radicals and non-free radicals. • Nitrogen-oxygen vacancies provide abundant local electrons for DO to form •O 2 −. This study utilized corn straw as the feedstock to synthesize biochar (BC) loaded with cobalt-zeolitic imidazolate framework nanoparticles and boron nitride quantum dots. The prepared BC composite, named BN 3 Z 0.5 BC, efficiently activated peracetic acid (PAA), resulting in the degradation of 94.8% of sulfadiazine (SDZ) in five minutes. Compared to pure BC, the SDZ removal rate increased nearly 5-fold. Mechanism analysis revealed that the main degradation pathway involves synergism between free and non-free radicals. The defect structure on the BC surface possesses a high charge density, stimulating PAA to produce more active species, while nitrogen–oxygen vacancy formation significantly promotes charge transfer. Besides, the unique structure of BC ensures good stability and recyclability, effectively controlling metal leaching. The BN 3 Z 0.5 BC/PAA system shows promising applicability across various water matrices, indicating a favorable application outlook. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochar loaded by CoFe 2 O 4 composite was high-efficient in peracetic acid activation. • Biochar and Fe(IV), Co(IV) were conductive to 1O 2 production in TCH degradation. • 10 mg/L TCH could be nearly degraded at 60 seconds via 1O 2 in CFB-2/PAA system. Corn straw and sludge-derived biochar composite (BC) loaded with CoFe 2 O 4 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 (1O 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 −/1O 2 and provide electrons to induce the formation of high-valent Fe(IV) and Co(IV). The oxygen vacancies on the surface of the CoFe 2 O 4 -loaded biochar composite (CFB-2) contribute partially to 1O 2 production through their transformation into a metastable intermediate with dissolved 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. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Adding sponge into CAnSMBR could increase nitrate removal efficiency. • Sponge could adsorb EPS and minimize membrane fouling in SAnSMBR. • Protein-like components of SMP were more vital for membrane fouling. • Less SMP and longer operational cycle was found in the SAnSMBR. Abstract This paper investigated a strategy to minimize membrane fouling and increase treatment efficiency through an investigation of a specific approach by adding sponges into a conventional submerged anaerobic membrane bioreactor (CAnSMBR). During the operation, the protein-based soluble microbial products as the main factor affecting the membrane fouling could be reduced by sponge addition in the CAnSMBR (SAnSMBR). Furthermore, reducing HRT from 18 h to 12 h could shorten the membrane fouling cycle to 62% and 87% in CAnSMBR and SAnSMBR, respectively. At the initial of COD/NO 3 ratio ranges from 5 to 4, only 88% of nitrogen in CAnSMBR was removed, while the SAnSMBR could remove more than 90%. TOC removal efficiency could reach more than 95% under a good stirring scenario. It is evident that the SAnSMBR is a promising solution for improving overall CAnSMBR performance and substantially mitigating membrane fouling. [ABSTRACT FROM AUTHOR]