Magnetic porous carbon materials derived from metal-organic framework in-situ growth on natural cellulose of wood for sulfadiazine degradation: Role of delignification and mechanisms

Advances of carbon-based materials for activating peracetic acid in advanced oxidation processes: A review

In recent years, the peracetic acid (PAA)-based advanced oxidation process (AOPs) has garnered significant attention in the field of water treatment due to rapid response time and environmentally-friendliness. The activation of PAA systems by diverse carbon-based materials plays a crucial role in addressing emerging environmental contaminants, including various types, structures, and modified forms of carbon materials. However, the structural characteristics and structure-activity relationship of carbon-based materials in the activation of PAA are intricate, while the degradation pathways and dominant active species exhibit diversity. Therefore, it is imperative to elucidate the developmental process of the carbon-based materials/PAA system through resource integration and logical categorization, thereby indicating potential avenues for future research. The present paper comprehensively reviews the structural characteristics and action mechanism of carbon-based materials in PAA system, while also analyzing the development, properties, and activation mechanism of heteroatom-doped carbon-based materials in this system. In conclusion, this study has effectively organized the resources pertaining to prominent research direction of comprehensive remediation of environmental water pollution, thereby elucidating the underlying logic and thought process. Consequently, it establishes robust theoretical foundation for future investigations and applications involving carbon-based materials/PAA system.

Efficient degradation of sulfadiazine via facilitated electron transfer by iron-carbon catalyst with highly exposed active sites

The inaccessible active sites, excessive metal leaching and radical mediated degradation pathway greatly hinder the performances of Fe-C composite catalyst oxidation process in the advanced oxidation water treatment. Herein, a facile method was developed to in situ growth of MIL-53 (Fe) on the powder active carbon (PAC) surface by a mild condition, which finally yields PAC supported Fe3O4@C particles (PAC@MOFs-2T) after heat treatment. The detailed characterizations indicate that the fine Fe3O4 particles encapsulated with carbon layers were evenly anchored on the PAC as active sites, which made the catalytic centers highly accessible for the peroxydisulfate activation and sulfadiazine degradation. In addition, the carbon layers, coated on the active sites could prevent the metal leaching during the catalytic process resulting in the high stability in a wide pH range. More attractively, the density functional theory (DFT) simulations and emperimental evidences further proved that the oxidation was dominated by a electron transfer process (ETP), during which, the peroxydisulfate (PDS) was adsorbed on Fe3O4 to form PDS∗ with high oxidation potential to initiate the ETP. Meanwhile, it was also demonstrated that the optimized sample PAC@MOFs-2T enriched with electron donating groups could selectively degrade the sulfadiazine, which avoid the negative impacts from the co-existed foreign ions and organic matters during the oxidation process. In addition, the toxicity analysis of intermediate products revealed that the sulfadiazine can be degradated into low-toxic or non-toxic products, which further permits viability of this ETP mediated advanced oxidation processes.

Fe loading 3D micro-meso-porous carbon sphere derived from natural cellulose of sawdust activating peroxymonosulfate for degradation of enrofloxacin

Fe loading 3D micro-meso-porous carbon sphere (Fe@3C-2N) was derived from natural cellulose of sawdust and melamine through sodium alginate and ferric chloride cross-linking followed by carbonization processes, which served as peroxymonosulfate (PMS) activators for enrofloxacin (ENR) degradation. The cellulose was produced by the delignification of sawdust with sodium chlorite. The delignification of sawdust and the addition of melamine increased the porosity and electron transport capacity of Fe@3C-2N. When the dosages of Fe@3C-2N and PMS were 0.60 g L-1 and 0.20 g L-1 respectively, the degradation rate of ENR (20 mg L-1) reached 92.17 % within 80 min, suggesting the satisfactory activation performance of PMS. The good structural stability of Fe@3C-2N makes it suitable for use as packing in continuous flow reactors for wastewater treatment. Quenching experiments and electron paramagnetic resonance (EPR) suggested that SO4•- and 1O2 were the dominant reactive oxygen species (ROSs) in Fe@3C-2N/PMS system. X-ray photoelectron spectroscopy (XPS) revealed that Fe3C, pyrrolic N and graphitic N were the potential active sites.