Effective utilization of CuO derived from waste printed circuit boards as a peroxymonosulfate activator for the degradation of reactive blue 19

• Cu-rich waste PCBs was reused to synthesize CuO catalyst for PMS activation. • The PCBs-CuO exhibited excellent performance and stability for RB19 degradation. • PCBs-CuO had good adaptability to pH, anions, and natural organic matter. • Singlet oxygen and hydroxyl radicals were the major reactive oxygen species. Waste printed circuit boards (PCBs), a common electronic waste, contain a high content of Cu. For environmental sustainability and economic benefit, it is necessary to recover the Cu as high value-added product instead of discarding it. In this work, Cu from PCBs was successfully recovered as CuO particles with high specific surface area and rich oxygen vacancies through cyclic leaching, chemical precipitation, low temperature aging, and calcination. Compared with CuO prepared from commercial Cu(NO 3 ) 2 ·5H 2 O, the PCBs-derived CuO (PCBs-CuO) exhibited comparable performance in activating peroxymonosulfate to degrade reactive blue 19, although its crystallinity and phase purity were relatively lower. Additionally, PCBs-CuO had an outstanding pH tolerance (2–12), confirming the practical application potential of PCBs-CuO in the removal of organic contaminants in various wastewater. Moreover, the quenching experiments, electrochemical measurements and electron paramagnetic resonance analysis suggested that 1 O 2 and ·OH played a significant role in PCBs-CuO/peroxymonosulfate system. The ≡Cu(II) and oxygen vacancies on the surface of PCBs-CuO was mainly responsible for the activation of peroxymonosulfate. This work provides a promising method for recycling metal from waste PCBs into high-effective peroxymonosulfate activator and simultaneously achieving environmental remediation.