Cavitation based Advanced Oxidation Processes for Wastewater Treatment – comparison of hydrodynamic and sonocavitation systems

Abstract

Cavitation based advanced oxidation processes (AOPs), are a promising alternative to currently used wastewater treatment technologies [1-2]. Amplified interest in this “hot” topic results in increased number of research on several aspects relating to formation of cavitation phenomena and its utilization for wastewater treatment as well as hybrid processes based of application of external oxidants effectively converted to radical species in cavitation conditions. The paper discusses a state of the art of cavitation based AOPs, as well as presents recent developments in this field of our research group. The principles of cavitation combined with AOPs will be presented followed by evaluation of their effectiveness in oxidation of organic contaminants and comparison of hydrodynamic and acoustic cavitation processes used for same type of pollutants. An examples of degraded particular pollutants will include chlorinated and nitro derivatives as well as other emerging environmental pollutants. Applications for disinfection of water will be also addressed. The paper will present also results of studies on degradation of pharmaceuticals as well as pre-treatment of real post-oxidative effluents formed during bitumen production as an examples of possible implementation of cavitation based processes in real industrial scenario [3-5]. Keywords: AOP; wastewater treatment; hydrodynamic cavitation; sonocavitation; acoustic cavitation References 1. Boczkaj G., Fernandes A. (2017), Wastewater treatment by means of Advanced Oxidation Processes at basic pH conditions: A review, Chem. Eng. J., 320, 608-633. 2. Gągol M., Przyjazny A., Boczkaj G. (2018), Wastewater treatment by means of advanced oxidation processes based on cavitation – A review, Chem. Eng. J., 338, 599-627. 3. Gągol M., Przyjazny A., Boczkaj G. (2018), Highly effective degradation of selected groups of organic compounds by cavitation based AOPs under basic pH conditions, Ultrason. Sonochem., 45, 257-266. 4. Gągol M., Przyjazny A., Boczkaj G. (2018), Effective method of treatment of industrial effluents under basic pH conditions using acoustic cavitation – a comprehensive comparison with hydrodynamic cavitation processes, Chem. Eng. Process., 128, 103-113. 5. Boczkaj G., Gągol M., Klein M., Przyjazny A. (2018), Effective method of treatment of effluents from production of bitumens under basic pH conditions using hydrodynamic cavitation aided by external oxidants, Ultrason. Sonochem., 40, 969-979.