Synergistic effect by supported activated carbon between functional groups and metal oxygen vacancies: enhancing ibuprofen degradation by improving ozone mass transfer†

Abstract

Catalytic ozonation is an effective method for wastewater purification. However, the low transfer of ozone in packed bubble columns leads to low ozone utilization efficiency, limited organic degradation, and high energy consumption. To address these issues, activated carbon supported catalysts, such as CuMn₂O₄@WAC and CuMn₂O₄@CSAC, have been developed, which exhibit excellent catalytic activity, stability, and high ozone utilization efficiency for the degradation of IBP in pharmaceutical wastewater. The addition of CuMn₂O₄@WAC or CuMn₂O₄@CSAC significantly increased the removal efficiency of IBP from 85% to 99%, while reducing energy consumption from 2.86 kW h m⁻³ to 0.80 kW h m⁻³ or 1.11 kW h m⁻³, respectively. Carboxyl groups on the surface of AC and oxygen vacancies on CuMn₂O₄ are key active sites for ozone adsorption and decomposition. Additionally, DFT calculations revealed that Mn–O_V sites on CuMn₂O₄ play a crucial role in these processes, where ozone is adsorbed and decomposed into atomic oxygen and peroxide. The synergy between activated carbon supported CuMn₂O₄ enhances mass transfer and promotes ozone decomposition, generating highly reactive species that effectively degrade IBP in pharmaceutical wastewater. Overall, utilizing activated carbon supported CuMn₂O₄ for catalytic ozonation presents a promising approach for pharmaceutical wastewater treatment.