Specific aspects of hydrodynamic cavitation in water treatment. An overview

This paper reviews the development and applications of hydrodynamic cavitation in water treatment, with a particular emphasis on the removal of organic and microbiological contaminants. A comparative analysis of published studies is conducted to evaluate the performance of various cavitation configurations, including Venturi tubes, diaphragm systems, and rotor-stator devices. The findings show that hydrodynamic cavitation combines mechanical, thermal, and radical mechanisms that enable the degradation of dyes, pharmaceutical residues, and persistent organic pollutants, as well as the inactivation of pathogenic microorganisms. The analysis identifies cavitation number, flow velocity, pressure drop, and physicochemical properties of the medium as key factors influencing process efficiency. Practical implications include reduced chemical demand and lower energy consumption compared with conventional disinfection methods. The review highlights the potential of hybrid systems (HC+O₃, HC+H₂O₂, HC+TiO₂/UV), which often achieve over 90% COD and TOC removal, and indicates directions for optimisation and scale-up of cavitation reactors.