1. Toward a better understanding of peroxymonosulfate and peroxydisulfate activation using a nano zero-valent iron catalyst supported on graphitized carbon: Mechanisms and application to the degradation of estrogenic compounds in different water matrix.
- Author
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Cai, Minjuan, Cheng, Peng, Li, Jinjun, Wu, Feng, Sarakha, Mohamed, Mailhot, Gilles, and Brigante, Marcello
- Subjects
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CATALYST supports , *IRON catalysts , *SEWAGE disposal plants , *PHOTOCATALYSIS , *WATER treatment plants , *PEROXYMONOSULFATE , *HYDROXYL group - Abstract
In this study, we employed nano zero-valent iron catalysts supported on graphitized carbon (GC-nZVI) catalyst to efficiently degrade BPA under circumneutral pH conditions in both dark and UVA radiation. The GC-nZVI catalyst was characterized using specific techniques (XPS, FTIR, BET, etc.), and was used to activate both PS and PMS in solution. Although no significant BPA degradation constant (k BPA) was determined using PS/PMS or GC-nZVI alone, a significant synergistic effect was observed in the system. Under dark conditions, k BPA increased from 0.01 min−1 to 0.17 when PS was used, both in the dark and under UVA. Notably, when PMS was present in the system, the improvement was even higher with k BPA reaching 0.18 and 0.26 min−1 under dark and UVA conditions, respectively. To further support the synergistic effect, it was found that 80% of mineralization was achieved within 2 h of UVA exposure. Chemical quenching experiments were conducted using selective probes and kinetic modelling showed that the activation of PS/PMS produced sulfate radicals (SO 4 •−), hydroxyl radicals (•OH) and ferryl ions (FeIVO2+) in both systems. Additionally, GC-nZVI/PMS system demonstrated good stability in recycling experiments, with up to 70% of BPA still being degraded after 3 cycled in 1 h under UVA. In conclusion, the degradation efficiencies of GC-nZVI/PMS and GC-nZVI/PS systems under dark and UVA radiation were assessed for three different EDCs (BPA, E2, and EE2) in both tap and sewage treatment plant waters. This study has demonstrated that the highly efficient GC-nZVI/PS/UVA or GC-nZVI/PMS/UVA system has significant potential for application in different water matrix, and our findings provide insights into the design of heterogeneous Fenton-like and photo-Fenton-like catalysts. [Display omitted] • GC-nZVI with PS and PMS systems is able to degrade and mineralize BPA in water. • The steady-state concentration of reactive species such as HO.•, SO 4 •- and FeVIO2+ is determined • The main degradation products of BPA are characterized. • Efficient BPA, E2 and EE2 degradation was obtained using GC-nZVI + PMS under UVA. • 60% of EDCs degradation in Tap and STP waters was reached after 90 min. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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