Lu Zijie, Bai Haokun, Liang Lanlan, Chen Shuo, Yu Hongtao, Quan Xie
Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, PR China.
Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, PR China.
J Hazard Mater. 2024 Aug 5;474:134842. doi: 10.1016/j.jhazmat.2024.134842. Epub 2024 Jun 5.
Heterogeneous catalytic ozonation (HCO) enables the destruction of organic pollutants in wastewater via oxidation by powerful hydroxyl radicals (·OH). However, the availability of short-lived ·OH in aqueous bulk is low in practical treatment scenarios due to mass transfer limitations and quenching of water constituents. Herein, we overcome these challenges by loading MgO catalysts inside the pores of a tubular ceramic membrane (denoted as CCM) to confine ·OH within the nanopores and achieve efficient pollutant removal. When the pore size of the membrane was reduced from 1000 to 50 nm, the removal of ibuprofen (IBU) by CCM was increased from 49.6 % to 90.2 % due to the enhancement of ·OH enrichment in the nanospace. In addition, the CCM exhibited high catalytic activity in the presence of co-existing ions and over a wide pH range, as well as good self-cleaning ability in treating secondary wastewater. The experimental results revealed that ·OH were the dominant reactive oxygen species (ROS) in pollutant degradation, while surface hydroxyl groups were active sites for the generation of ·OH via ozone decomposition. This work provides a promising strategy to enhance the utilization of ·OH in HCO for the efficient degradation of organic pollutants in wastewater under spatial confinement.
多相催化臭氧化（HCO）能够通过强氧化性的羟基自由基（·OH）氧化作用来降解废水中的有机污染物。然而，在实际处理场景中，由于传质限制和水中成分的猝灭作用，水体中短寿命的·OH利用率较低。在此，我们通过将氧化镁催化剂负载在管状陶瓷膜（记为CCM）的孔内，将·OH限制在纳米孔内，从而克服这些挑战，实现高效的污染物去除。当膜的孔径从1000纳米减小到50纳米时，由于纳米空间中·OH富集的增强，CCM对布洛芬（IBU）的去除率从49.6%提高到90.2%。此外，CCM在共存离子存在的情况下以及较宽的pH范围内均表现出高催化活性，并且在处理二级废水时具有良好的自清洁能力。实验结果表明，·OH是污染物降解过程中的主要活性氧物种（ROS），而表面羟基是通过臭氧分解产生·OH的活性位点。这项工作为在空间限制条件下提高HCO中·OH的利用率以高效降解废水中的有机污染物提供了一种有前景的策略。
