A Review on Hydrodynamic Cavitation as a Treatment Option for Refractory Organics Removal

Effluents from different industries such as pharmaceutical, pesticides, dyes and dye intermediates are increasing day by day. Different Advanced Oxidation Processes such as Fenton, photo catalytic, hydrodynamic, acoustic cavitation processes, etc. are used to mineralize complex molecules of these effluents which are not easily biodegradable. Among these processes, Hydrodynamic Cavitation has emerged as a new energy-efficient technology for the treatment of various bio-refractory pollutants present in aqueous effluent. Hydrodynamic Cavitation involves the use of a cavitating device for the treatment of wastewater. In present work, the current status of Hydrodynamic Cavitation reactors has been reviewed discussing cavitational yield. Operating parameters like pH, temperature, pressure, flow rate are also varied. Also, Cavitational reactors are compared with Sonochemical reactors and hydrodynamic cavitation reactors found to be more efficient. There are various advantages of combining Hydrodynamic Cavitation with other oxidants and other Advanced Oxidation Processes such as H2O2, ozone, and photocatalytic process have been discussed with some recommendation for large-scale operation.