Laboratory of Engineering Ecology, Baikal Institute of Nature Management, Siberian Branch of Russian Academy of Sciences, Ulan-Ude, Russia.
Laboratory of Engineering Ecology, Baikal Institute of Nature Management, Siberian Branch of Russian Academy of Sciences, Ulan-Ude, Russia.
Water Res. 2020 Sep 1;182:116016. doi: 10.1016/j.watres.2020.116016. Epub 2020 Jun 8.
Since the early 2000s, dual-frequency ultrasound (DFUS) has received much attention for synergistically enhanced elimination of organic pollutants and pathogenic microorganisms from water. In the present review, we have surveyed recent developments in acoustic physics to elucidate the mechanism of synergistic effect under exposure of aqueous media to DFUS. Briefly, the nonlinear dynamics of microbubbles upon DFUS exposure produces additional frequencies, such as harmonics, subharmonics, ultraharmonics and combination frequencies. These increase the probability of bubbles collapse, thereby enhancing cavitation and generating more reactive oxygen species (ROS) for advanced oxidation processes (AOPs). Further, literature data on ROS generation, chemical degradation and microbial inactivation in aqueous media through DFUS alone and DFUS-based AOPs (involving oxidants or catalysts) have been discussed. In this regard, optimal frequency combination, sonoreactor type and transducer arrangement appear to be key parameters for achieving a high synergistic effect. Strengths and shortcomings of DFUS to water treatment and disinfection have been identified and future research directions have been proposed. Though most studies were conducted on pure (matrix-free) aqueous solutions, these AOPs could be applicable for treating real waters.
自 21 世纪初以来，双频超声（DFUS）因其协同增强水中有机污染物和病原微生物的消除而受到广泛关注。在本综述中，我们调查了声学物理的最新进展，以阐明在 DFUS 暴露下水介质的协同效应机制。简而言之，DFUS 暴露下微泡的非线性动力学会产生额外的频率，如谐波、次谐波、超谐波和组合频率。这些频率增加了气泡破裂的概率，从而增强了空化作用，并产生更多的活性氧物质（ROS）用于高级氧化工艺（AOPs）。此外，还讨论了通过 DFUS 单独和基于 DFUS 的 AOP（涉及氧化剂或催化剂）在水介质中产生 ROS、化学降解和微生物失活的文献数据。在这方面，最佳频率组合、声反应器类型和换能器布置似乎是实现高协同效应的关键参数。已经确定了 DFUS 在水处理和消毒方面的优缺点，并提出了未来的研究方向。尽管大多数研究都是在纯（无基质）水溶液中进行的，但这些 AOP 可用于处理实际水样。
