In-situ regeneration of tetracycline-saturated hierarchical porous carbon by peroxydisulfate oxidation process: Performance, mechanism and application

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2022-01, Vol.427, p.131749, Article 131749
• Main Authors: Pi, Zhoujie, Hou, Kunjie, Yao, Fubing, He, Li, Chen, Shengjie, Tao, Ziletao, Zhou, Puyu, Wang, Dongbo, Li, Xiaoming, Yang, Qi
• Format: Article
• Language: English
• Subjects: Bifunctional material; Electron-transfer; In-situ regeneration; Nitrogen-doped hierarchical porous carbon; Peroxydisulfate; Single oxygen
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2021.131749

[Display omitted] •Bifunctional NHGBC-800 can adsorb TC and activate PDS with itself as the activator.•NHBC-800 could maintain above 77.18% adsorption capacity after the 6th cycles.•Non-radical electron-transfer and 1O2 pathways dominated the regeneration process.•PDS oxidation can regenerated carbon material saturated by organic pollutants well. Carbonaceous material is not only the excellent adsorbent for organic contaminants removal, but also the effective activator for peroxydisulfate (PDS) activation. In this study, a nitrogen-doped hierarchical porous carbon material (NHGBC-800) presented the attractive bifunctional properties was developed for the removal of model organic contaminant antibiotic tetracycline (TC). On the one aspect, the NHGBC-800 had a large specific surface area (1178.0 m2/g) and achieved good TC removal with a maximal adsorption capacity (Qm) of 629.76 mg/g at 303 K. On the other aspect, TC-saturated NHGBC-800 could effectively activate PDS with itself as the activator, by which the mineralization of desorbed TC and in-situ regeneration of exhausted adsorbent were achieved simultaneously. The Qm of NHGBC-800 recovered 90.61% after first regeneration and still retained 77.18% even after the 6th adsorption-regeneration cycles. Moreover, the as-prepared material maintained good adsorption and regeneration performance under a wide range of pH conditions (3.02–9.83) and in the presence of inorganic anions such as Cl−, SO42−, NO3−, H2PO4−, HCO3−. The electro spin resonance (ESR), reactive oxygen species (ROS) quenching studies and electrochemical measurement revealed that the electron-transfer and single oxygen mediated the non-radical pathways dominated the TC degradation during the regeneration process. Compared with the conventional thermal and electrochemical regenerations, the in-situ regeneration of bifunctional carbon materials induced by PDS activation is more effective, sustainable and environmental-friendly.