Activation of peroxymonosulfate by single-atom Fe-g-C3N4 catalysts for high efficiency degradation of tetracycline via nonradical pathways: Role of high-valent iron-oxo species and Fe–Nx sites

Singlet oxygen-dominated activation of peroxymonosulfate by passion fruit shell derived biochar for catalytic degradation of tetracycline through a non-radical oxidation pathway.

In this study, the performance of periodate (PI) on sulfadiazine (SDZ) degradation was evaluated using coagulation solid waste fabricated catalyst (CWBC), obtained by simple pyrolysis. SDZ effectively underwent 98.94% remove within 90 min in the CWBC/PI system. Electron transfer was the predominant mechanism due to the development of an electronic cycle among SDZ, CWBC and PI, where the O 2 •− , PFRs, and the reactive iodine species had minor roles. Density functional theory calculations identified that Fe and N could change the electron configuration and break the chemical inertness of carbonaceous material. As a result, electrons on the carbon matrix of CWBC are inclined to travel through the formed Fe–O covalent bond to PI. Further analysis demonstrated that SO 4 2− , humic acid (HA), as well as anoxic conditions greatly facilitated SDZ degradation. This study provides a facile protocol for converting coagulation waste to an efficient catalyst and provides fundamental insights into the degradation mechanisms of micropollutants by activating PI. • A carbonaceous catalyst was prepared from coagulation waste to activate periodate. • Electron transfer has a dominant effect on sulfadiazine degradation. • Fe and N could change the electron configuration of carbonaceous catalyst. • Chemisorption between Fe and PI was the key step for the catalytic process. • Sulfadiazine removal can be significantly enhanced under anoxic conditions. 

Fe, N-doped carbonaceous catalyst activating periodate for micropollutant removal: Significant role of electron transfer

In this study, the performance of periodate (PI) on sulfadiazine (SDZ) degradation was evaluated using coagulation solid waste fabricated catalyst (CWBC), obtained by simple pyrolysis. SDZ effectively underwent 98.94% remove within 90 min in the CWBC/PI system. Electron transfer was the predominant mechanism due to the development of an electronic cycle among SDZ, CWBC and PI, where the O2•−, PFRs, and the reactive iodine species had minor roles. Density functional theory calculations identified that Fe and N could change the electron configuration and break the chemical inertness of carbonaceous material. As a result, electrons on the carbon matrix of CWBC are inclined to travel through the formed Fe–O covalent bond to PI. Further analysis demonstrated that SO42−, humic acid (HA), as well as anoxic conditions greatly facilitated SDZ degradation. This study provides a facile protocol for converting coagulation waste to an efficient catalyst and provides fundamental insights into the degradation mechanisms of micropollutants by activating PI.

Meng Xu

Papers

Goethite/biochar-activated peroxymonosulfate enhances tetracycline degradation: Inherent roles of radical and non-radical processes