Research progress of hydrodynamic cavitation reactors in the field of water treatment: A review

Abstract

With the rapid development of industrialization and urbanization, water environmental pollution has become one of the important issues facing the world. As a potential device that can efficiently treat organic pollutants, hydrodynamic cavitation reactors (HCRs) have become one of the research hotspots of hydrodynamic cavitation technology in recent decades. In order to better provide generous base-knowledge to researchers with a non-engineering background or few cavitation fundamentals, to avoid unreasonable strategies for selecting an applicable HCR. This review provides a systematic overview of the principles and structures of four types of HCRs that are frequently used. Firstly, it summarizes the structural and environmental parameters in this process, as well as their impacts on the cavitation intensity of HCRs when synergistically combined with other advanced oxidation processes (AOPs) technology. Meanwhile, the specific improved methods and relating enhanced performance of cavitation reactors are also summarized. Then, the degradation efficiency of pollutants in wastewater is compared among these four types of HCRs. In addition, the application of combined reactors and other HCRs in the field of water treatment is also specially introduced. Finally, based on the current development status and shortcomings of HCRs in this field, the development prospects of HCRs are discussed. It is expected that the present paper would provide decision-making support for cavitation-beginners to use this emerging technology and promote the advancement of cavitation reactors in the field of wastewater treatment.