Cu 2 (OH) 3 NO 3 /γ-Al 2 O 3 catalyzes Fenton-like oxidation for the advanced treatment of effluent organic matter (EfOM) in fermentation pharmaceutical wastewater: The synergy of Cu 2 (OH) 3 NO 3 and γ-Al 2 O 3 .

The secondary effluent of fermentation pharmaceutical wastewater exhibits high chromaticity, elevated salinity, and abundant refractory effluent organic matter (EfOM), presenting significant treatment challenges and environmental threats. Herein, Cu ₂ (OH) ₃ NO ₃ /γ-Al ₂ O ₃ was fabricated through ultrasound-assisted impregnation and calcination to catalyze the Fenton-like oxidation for degrading organic pollutants in this secondary effluent. Under neutral conditions, with 400.00 mg/L H ₂ O ₂ , 8 g/L catalyst, and at 30 ℃, the EfOM and COD _Cr removal efficiencies can reach 96.90 % and 51.56 %, respectively. The Cu ₂ (OH) ₃ NO ₃ /γ-Al ₂ O ₃ catalyst possesses ideal reusability, maintaining COD _Cr , chromaticity, and EfOM removal efficiencies at 44.44 %-64.59 %, 85.45 %-93.45 %, and 61.00 %-95.00 % over 220 h in a continuous-flow catalytic oxidation system operated at room temperatures (15-25 ℃). Electron paramagnetic resonance results and density functional theory calculations indicate that •OOH may be the predominant reactive oxygen species, facilitated by the easier elongation of the OH bond in H ₂ O ₂ compared to the OO bond. The adjusted electronic structure endows Cu ₂ (OH) ₃ NO ₃ /γ-Al ₂ O ₃ composite sites with superior catalytic selectivity for H ₂ O ₂ activation compared to Cu ₂ (OH) ₃ NO ₃ single crystal sites, with γ-Al ₂ O ₃ additionally facilitating H ₂ O ₂ activation through electron donation. This research highlights the efficacy of Cu ₂ (OH) ₃ NO ₃ /γ-Al ₂ O ₃ in the advanced treatment of complex industrial wastewater, elucidating its catalytic mechanisms and potential applications.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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