Fouling is one of the most challenging problems impacting the performance of membrane-based separation technology. In recent years, ultrasound have been widely applied as an unconventional method to control membrane fouling, as well as to enhance membrane cleaning. The aim of the present work is to review the current literature and the recent developments related to the use of ultrasound as an innovative and alternative approach to improve the fouling behavior of membrane separation processes. The theory underlying ultrasonic-assisted phenomena is reviewed, together with operational factors that influence the effectiveness of the ultrasound treatment, such as frequency, power intensity, pressure, temperature, pH, and operation mode. Ultrasound irradiation effectively aids the cleaning of contaminated surfaces and enhances the permeate flux, owing to cavitation phenomena and powerful convective currents, associated with secondary phenomena, such as microstreamers, shock waves, and heating. However, the lifetime of the membranes should be carefully evaluated when applying ultrasonication as a technique of cleaning or controlling membrane fouling. Indeed, the integrity of membranes after sonication and the control of erosion produced by high ultrasonic intensities are key issues hindering the scale-up of this approach in the membrane industry. This reviews highlights the topics requiring more investigations, specifically to evaluate the economic aspects of ultrasonic assisted fouling control and cleaning in membrane processes.

中文翻译：

---

超声波辅助污垢控制和污垢膜清洁的批判性评论

污染是影响膜分离技术性能的最具挑战性的问题之一。近年来，超声波作为一种非常规方法被广泛应用于控制膜污染以及增强膜清洁。本工作的目的是回顾当前的文献和与使用超声波作为改善膜分离过程结垢行为的创新和替代方法相关的最新发展。回顾了超声辅助现象的理论基础，以及影响超声治疗有效性的操作因素，例如频率、功率强度、压力、温度、pH 值和操作模式。超声波辐照有效地帮助清洁受污染的表面并提高渗透通量，由于空化现象和强大的对流，与次生现象相关，例如微流光、冲击波和加热。然而，当应用超声波作为清洁或控制膜污染的技术时，应仔细评估膜的寿命。事实上，超声处理后膜的完整性和控制高超声强度产生的侵蚀是阻碍这种方法在膜工业中扩大规模的关键问题。该评论突出了需要更多调查的主题，特别是评估膜过程中超声波辅助污垢控制和清洁的经济方面。在应用超声波作为清洁或控制膜污染的技术时，应仔细评估膜的寿命。事实上，超声处理后膜的完整性和控制高超声强度产生的侵蚀是阻碍这种方法在膜工业中扩大规模的关键问题。该评论突出了需要更多调查的主题，特别是评估膜过程中超声波辅助污垢控制和清洁的经济方面。在应用超声波作为清洁或控制膜污染的技术时，应仔细评估膜的寿命。事实上，超声处理后膜的完整性和控制高超声强度产生的侵蚀是阻碍这种方法在膜工业中扩大规模的关键问题。该评论突出了需要更多调查的主题，特别是评估膜过程中超声波辅助污垢控制和清洁的经济方面。超声处理后膜的完整性和控制高超声强度产生的侵蚀是阻碍这种方法在膜工业中扩大规模的关键问题。该评论突出了需要更多调查的主题，特别是评估膜过程中超声波辅助污垢控制和清洁的经济方面。超声处理后膜的完整性和控制高超声强度产生的侵蚀是阻碍这种方法在膜工业中扩大规模的关键问题。该评论突出了需要更多调查的主题，特别是评估膜过程中超声波辅助污垢控制和清洁的经济方面。