Catalytic oxidation pretreatment is a significant focus in the field of membrane fouling control; however, traditional catalytic materials are plagued by limitations in catalytic sites and challenges in recovery. In this study, a novel catalyst, B-doped NiFe 2 O x , was prepared with magnetic recovery capabilities and abundant oxygen vacancies to address landfill leachate treatment and mitigate membrane fouling. The results demonstrated the efficient activation of persulfate (PS) by the catalytic sites on B-NiFe 2 O x , which significantly degraded the complex organic pollutants like conjugated double bonds and aromatic compounds in landfill leachate. A large amount of humic acid and soluble microbial products in the landfill leachate were efficiently degraded upon contact with sulfate and hydroxyl radicals produced by B-NiFe 2 O x /PS, thereby resulting in achieving a chemical oxygen demand removal efficiency of up to 72 % and more than a twofold enhancement in filtration flux. Moreover, the characteristics of the fouled layer reveal that the B-NiFe 2 O x /PS system facilitated the formation of a porous cake layer, maximizing the retention of functional groups on the NF270 membrane surface. Notably, a minor presence of B-NiFe 2 O x is uniformly distributed within the cake layer, indicating the in-situ occurrence of weak catalytic oxidation reactions. This study provides an effective and innovative approach utilizing catalytic oxidation for membrane fouling control.
To address the challenges associated with traditional interface catalytic oxidation membranes, such as preparation complexity, limited reaction sites, and poor reusability, a novel recyclable pre-deposited dynamic catalytic membrane was developed for the first time. Specifically, a B-doped NiFe 2 O x catalyst with magnetic and many oxygen vacancies was synthesized and simply pre-deposited onto the surface of an ultrafiltration membrane to activate peroxydisulfate (PDS). The results indicated that the abundant active catalytic sites on the dynamic deposition layer of B-NiFe 2 O x could efficiently activate PDS, thereby facilitating the generation of active species predominantly comprising sulfate and hydroxyl radicals. As a result, there was a 67.14% significant removal of chemical oxygen demand in secondary effluent. Furthermore, even after 8 cycles of magnetic recovery and re-deposition, the normalized flux of the dynamic catalytic oxidation membrane continued to maintain at 0.52. Notably, unlike conventional interface catalytic oxidation membranes, some B-NiFe 2 O x within the dynamic layer engaged in the catalytic oxidation process in a free form, which maximized the oxidation rate and enhanced membrane in-situ cleaning performance. This research contributes to a comprehensive understanding of utilizing pre-deposited dynamic catalytic oxidation membranes and proposes an effective long-term strategy for membrane in-situ cleaning and wastewater treatment.
危险品化学品经营许可证（带存储）