A Review on the Application of Hydrodynamic Cavitation Method in Combination with Other Advanced Oxidation Processes for Dye Removal

Until now, various chemical treatments (oxidation and electrochemical destruction), biological treatments (microbial cultures and anaerobic bioremediation systems) and physical treatments (such as adsorption and ion exchange) have been proposed to remove dyes as one of the most important water pollutants. In this study, hydrodynamic cavitation (bubble formation in a liquid) was considered as a new method for dye removal. The important advantages of this method are no need to use chemicals, low energy consumption and the ability to combine with other advanced oxidation processes. A literature review on dye removal focusing on combination with other advanced oxidation processes indicated that orifice plates and venturi tubes are often used and less than 2 h (in optimum operating conditions) more than 80% of dye was removed. Also, factors such as device geometry, inlet pressure, operating temperature, pH and liquid properties (like vapor pressure, viscosity and surface tension) are effective parameters in this process. The results of previous works imply excellent efficiency of this method in combination with other processes and methods such as Fenton, photocatalytic, ozonation, aeration and presence of various metal and non-metallic ions in the reaction medium. Also, flexibility in designing and combining with advanced oxidation processes, depend on the purpose, are another major and important advantages for replacing this method with conventional methods in the near future.