High-efficiency treatment of electroless nickel plating effluent using core-shell MnFe2O4-C@Al2O3 combined with ozonation: Performance and mechanism

• Published in: Journal of hazardous materials 2022-07, Vol.433, p.128768-128768, Article 128768
• Main Authors: Guan, Zhijie, Guo, Yanping, Mo, Zhihua, Chen, Shaojin, Liang, Jialin, Liao, Xiaojian, Zhang, Yumin, Huang, Zhenhua, Song, Weifeng, Xu, Yanbin, Ou, Xuelian, Sun, Shuiyu
• Format: Article
• Language: English
• Subjects: Catalytic active sites; Core-shell MnFe2O4-C@Al2O3; Heterogeneous catalytic ozonation; Reactive oxygen species; Total nickel
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2022.128768

Heterogeneous catalytic ozonation (HCO) has been widely applied for the treatment of wastewater. In order to maintain the structural stability and surface catalytic activity of heterogeneous catalysts during the HCO treatment of electroless nickel plating effluent (ENPE), a MnFe2O4-C@Al2O3 catalyst with a core-shell structure was synthesized. MnFe2O4-C@Al2O3 was characterized and applied in the removal of total nickel (TNi) and organic contaminants from actual ENPE, using a coupled system of HCO combined with a magnetic dithiocarbamate chelating resin (MnFe2O4-C@Al2O3/O3-MDCR). Results show that embedding Al2O3 with C and MnFe2O4 significantly increased the TNi removal efficiency (99.3%), enhanced the O3-utilization efficiency and improved the generation of reactive oxygen species (ROS). The reaction rate (k = 0.7641 min−1) and O3-utilization efficiency established for TNi removal (ΔTNi/ΔO3 =0.221) by the MnFe2O4-C@Al2O3/O3-MDCR system, were 220% and 140% higher than the Al2O3/O3-MDCR system, respectively. Catalytic mechanism analysis demonstrated that surface hydroxyl groups, oxygen vacancy, metals, the carbon surface and its functional groups, can all potentially serve as catalytic active sites, with 1O2 and •OH considered to the predominant ROS. Overall, these findings verify that the synthesized MnFe2O4-C@Al2O3 catalyst possesses excellent catalytic capabilities and outstanding structural stability, making it suitable for practical application in the treatment of wastewater effluent. [Display omitted] •Core-shell MnFe2O4-C@Al2O3 was synthesized with superior mechanical stability.•MnFe2O4-C@Al2O3 showed excellent catalytic performance and brilliant O3-utilization.•Abundant catalytic active sites were beneficial to the generation of various ROS.•High removal on TNi, COD and TOC of ENPE by MnFe2O4-C@Al2O3/O3-MDCR system.•Novel FPE was constructed and firstly applied to assess the toxicity of ENPE.