State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China; School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States.
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China.
Water Res. 2024 Nov 1;265:122295. doi: 10.1016/j.watres.2024.122295. Epub 2024 Aug 18.
Micro and nanobubbles (MNBs), as an efficient and convenient method, have been widely used in water treatment. Composed of gas and water, MNBs avoid directly introducing potential secondary pollutants. Notably, MNBs exhibit significant advantages through interface reactions in assisting AOPs. They overcome barriers like low mass transfer coefficients and limited reactive sites, and shorten the distance between pollutants and oxidants, achieving higher pollutant removal efficiency. However, there is a lack of systematic summary and in-depth discussion on the fundamental mechanisms of MNBs-assisted AOPs. In this critical review, the characteristics of MNBs related to water treatment are outlined first. Subsequently, the recent applications, performance, and mechanisms of MNBs-assisted AOPs including ozone, plasma, photocatalytic, and Fenton oxidation are overviewed. We conclude that MNBs can improve pollutant removal mainly by enhancing the utilization of reactive oxygen species (ROS) generated by AOPs due to the effective interface reactions. Furthermore, we calculated the electrical energy per order of reaction (EE/O) parameter of different MNBs-assisted AOPs, suggesting that MNBs can reduce the total energy consumption in most of the tested cases. Finally, future research needs/opportunities are proposed. The fundamental insights in this review are anticipated to further facilitate an in-depth understanding of the mechanisms of MNBs-assisted AOPs and supply critical guidance on developing MNBs-based technologies for water treatment.
微纳米气泡（MNBs）作为一种高效便捷的方法，已广泛应用于水处理中。MNBs 由气体和水组成，避免了直接引入潜在的二次污染物。值得注意的是，MNBs 通过在 AOPs 中进行界面反应，表现出显著的优势。它们克服了传质系数低和反应位点有限等障碍，缩短了污染物和氧化剂之间的距离，从而提高了污染物的去除效率。然而，目前缺乏对 MNBs 辅助 AOPs 基本机制的系统总结和深入讨论。在本综述中，首先概述了与水处理相关的 MNBs 的特性。随后，综述了 MNBs 辅助的包括臭氧、等离子体、光催化和芬顿氧化在内的 AOPs 的最新应用、性能和机制。我们得出结论，MNBs 可以通过有效界面反应增强 AOPs 产生的活性氧物质（ROS）的利用，从而主要提高污染物的去除效率。此外，我们还计算了不同 MNBs 辅助 AOPs 的反应级数电能量（EE/O）参数，表明在大多数测试案例中，MNBs 可以降低总能耗。最后，提出了未来的研究需求/机会。本综述中的基本见解有望进一步促进对 MNBs 辅助 AOPs 机制的深入理解，并为开发基于 MNBs 的水处理技术提供关键指导。
