Cu(III) generation and air sparging extend catalytic effectiveness of Cu2S/H2O2 from neutral to acidic condition: performance and mechanism in comparison with CuS/H2O2. (1st January 2021)

• Record Type: Journal Article
• Authors: He, Hongping; Sun, Mei; Wu, Deli; Di, Guanglan; Fei, Xunchang
• Is Part Of: Journal of cleaner production. Volume 278(2021)
• Publication Date: 2021-01-01
• Subjects: Cu2S/H2O2 -- CuS/H2O2 -- Cu(III) -- Differentiated mechanism -- air sparging; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2020.123572
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Heterogeneous Fenton dominated by ·OH is limited in its application, as pre-acidification is required to maximize the generation amount and redox potential of ·OH. It is thus featured to consume resources and generate pollutants. In this study, both CuS/H2 O2 and Cu2 S/H2 O2 are found to show better performances under close-to-neutral condition (pH 5.0 to 9.0) than acidic condition (pH 3.0) when degrading a model contaminant, sulfamethazine (SMZ), because ·OH does not play a major role in both systems. The Cu valence-dependent catalytic mechanisms are responsible for the varied kinetics between CuS/H2 O2 and Cu2 S/H2 O2 . In CuS/H2 O2, Cu(III) and 1 O2 contribute to the SMZ degradation, and their contributions are pH-dependent. In Cu2 S/H2 O2, Cu(III) is responsible for the degradation regardless of the pH. Both systems with optimal performances under neutral condition are advantageous as pre-acidification can be avoided. In addition, air sparging induces additional 16% SMZ degradation in Cu2 S/H2 O2 under acidic condition, because the sparged O2 reacts with dissolved Cu(I). The more O2 reacts with the dissolved Cu(I), the less generated Cu(III) is ineffectively depleted. Air sparging is readily applicable to different operations, thus its combination with Cu2 S/H2 O2 potentially benefits the development of environmentally-friendly treatment process for industrial wastewater. Highlights: CuS/H2 O2 and Cu2 S/H2 O2 are more effective under neutral than acidic condition. Cu(III) is critical in Cu2 S/H2 O2, independent of solution pH. Cu(III) and 1 O2 are critical in CuS/H2 O2, but pH dependent. Air sparging is an cleaner alternative to improve the Cu2 S/H2 O2 performance.