Highly efficient activation of peracetic acid by nano-CuO for carbamazepine degradation in wastewater: The significant role of H2O2 and evidence of acetylperoxy radical contribution.

Peracetic acid (PAA)-based advanced oxidation processes (AOPs) has attracted increasing attentions towards contaminant degradation in the wastewater treatment. Herein, we report the efficient activation of PAA by nano-CuO (nCuO/PAA) to degrade carbamazepine (CBZ) for the first time. Rapid degradation of CBZ was observed in the nCuO/PAA system at neutral initial pH. A new scavenging experiment with Mn2+ as a specific scavenger was developed to distinguish the dominant role of CH3C(O)OO● for CBZ degradation in the nCuO/PAA process. The oxidation of CBZ by CH3C(O)OO● was verified to proceed via the electrons transfer, and the acute and chronic toxicity of the transformation products was significantly reduced. The efficient activation of PAA by nCuO was found to be realized through continuous conversion of Cu(II) to Cu(I), which was significantly boosted by co-existing H2O2. The nCuO/PAA process was slightly affected by the water matrices, and maintained high efficiency in real water samples. The findings obtained in this study provide new insights into the catalytic formation of CH3C(O)OO● from PAA and facilitate the development and application of PAA-based AOPs in wastewater treatment.