V₂O₅/RGO/Pt nanocomposite on oxytetracycline degradation and pharmaceutical effluent detoxification

Abstract

BACKGROUND: Antibiotics have been identified as significant pollutants owing to their adverse impact on the environment through the development of antibiotic-resistant bacteria. In a previous study, an e-waste-based reduced graphene oxide-V 2 O 5 -platinum (RGOV-Pt(1%)) nanocomposite was prepared and subsequently used for the photocatalytic degradation of oxytetracycline (OTC), a tetracycline group of antibiotics. RESULTS:This study aimed to assess the impact of additives such as H 2 O 2 , NaCl, Na 2 CO 3 , ethanol and persulfate on the photocatalytic degradation of OTC using RGOV-Pt(1%) nanocomposite. The results showed that the degradation efficiency decreased in the presence of NaCl and Na 2 CO 3 owing to the electron-hole scavenging property of their anions. Low concentrations of H 2 O 2 (up to 10 mmol L -1 ) increased the OTC degradation efficiency, whereas high concentrations decreased the OTC degradation owing to the quenching of hydroxyl radicals. However, the presence of persulfate increased the OTC degradation efficiency owing to the formation of hydroxyl radicals. Furthermore, the OTC degradation pathway was elucidated using high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS). The study was extended to real pharmaceutical effluent and the degradation efficiency was found to be less for real effluent (87%) in comparison with OTC (99%) in aqueous solution.CONCLUSION: RGOV-Pt(1%) photocatalyst effectively degraded OTC. An OTC degradation pathway was proposed based on the intermediates formed. The impact of additives was established. Effective real pharmaceutical effluent detoxification was observed. Thus the synthesized RGOV-Pt(1%) nanocomposite is a hopeful alternative for the removal of antibiotics in contaminated waters and sites.1.5 g L −1 (Fig. 4(C)). Almost complete degradation (99%) was observed in the absence of NaCl at the end of 60 min, while the degradation efficiency decreased to 78% with increased concentration of NaCl (1.5 g L −1 ). The decrease in the OTC degradation is J Chem Technol Biotechnol 2020; 95: 297-307

Enhanced visible light photocatalysis with E‐waste‐based V2O5/zinc–ferrite: BTEX degradation and mechanism

“…46 The wileyonlinelibrary.com/jctb presence of chloride anions blocks the active sites at the catalyst-BTEX interface and inhibits the efficiency of the photocatalytic degradation processes. 46,47 The decrease in the degradation of BTEX in the presence of carbonate ions is due to the hydroxyl scavenging property of carbonate ions, 48 as in Eqn (6) 48,49 :…”

“…Chloride ions are very stable and are not readily oxidizable . The presence of chloride anions blocks the active sites at the catalyst–BTEX interface and inhibits the efficiency of the photocatalytic degradation processes …”

Graphene-Based Composites as Catalysts for the Degradation of Pharmaceuticals

“…The composite also showed sufficient stability, with up to 100% efficiency still recorded after 3 cycles of usage. Similarly, Mohan, et al [151] reported the degradation of oxytetracycline by V 2 O 5 /rGO/Pt composites. The study focused on the effect of additives such as H 2 O 2 , Na 2 CO 3 , ethanol, persulfate and NaCl on the degradation efficiency of the photocatalyst.…”

Performance improvement of the photocatalytic process for the degradation of pharmaceutical compounds using new POM/polymer photocatalysts

“…Conventional treatments such as physical and chemical methods, biodegradation, chemical and electrochemical oxidation have been applied for the degradation of these different drugs 1,3,8 . However, these processes don't lead to a total mineralization of this products but most of the time transform them from one phase to another 9 . Hence, Advanced Oxidation processes (AOP), based on the production of highly reactive chemical including hydroxyl and superoxide anions radicals, have appeared as a new and performant technique for the total removal and mineralization of numerous emergent pollutants 4,5,10 .…”