Mg6MnO8负载陶瓷膜限域增强催化臭氧氧化去除有机污染物

Mg6MnO8-loaded ceramic membranes with spatial confinement for enhanced catalytic ozonation in removing organic pollutants

中文关键词: 纳米限域效应  催化陶瓷膜  催化臭氧氧化  水处理

英文关键词: nanoconfinement effect  catalytic ceramic membrane  catalytic ozonation  water treatment

中文摘要:

      非均相催化臭氧氧化可通过产生强氧化性的活性氧物种(ROS)去除水中的有机污染物．然而在实际处理场景中，由于传质限制使水相中短寿命的ROS难以得到有效利用．因此，通过在管式陶瓷膜的孔隙内部负载Mg6MnO8制备催化陶瓷膜(CCM)，从而将其催化臭氧产生的ROS限制在有效的扩散距离内，实现了污染物的高效去除．当CCM的孔径从1 000 nm减小到100 nm时，由于纳米限域对ROS富集作用的增强，四环素的矿化率从49.8%提高到72.6%．此外，在实际水的处理中，该限域CCM在高效去除污染物的同时，还表现出优异的抗污染性能．实验结果表明，催化剂表面羟基的质子化和Mn位点上的电子转移协同诱导臭氧分解生成·OH和 1O2．该工作为通过纳米限域效应高效利用ROS去除水中难降解有机污染物提供了技术支撑．

英文摘要:

      Heterogeneous catalytic ozonation removes organic pollutants in water via the generation of powerful reactive oxygen species (ROS). However, the availability of short-lived ROS in aqueous bulk is low in practical treatment scenarios due to mass transfer limitations. Herein, efficient pollutant removal is achieved by loading Mg6MnO8 into the pores of tubular ceramic membranes for preparation of catalytic ceramic membranes (CCM) to confine the generated ROS within an effective diffusion distance. When the pore size of the CCM is reduced from 1 000 nm to 100 nm, the mineralization of tetracycline increases from 49.8% to 72.6%, which is attributed to the enhancement of ROS enrichment at the nanoscale. In addition, while the CCM with spatial confinement has efficient pollutant removal during the treatment of real water, it also exhibits excellent anti-fouling properties. The experimental results reveal that the protonation of surface hydroxyl groups of the catalyst and the electron transfer on the Mn sites synergistically induce the O3 decomposition to generate ·OH and 1O2. The work provides technical support for the efficient utilization of ROS to remove refractory organic pollutants in water under nanoconfinement effect.