Sonochemical reactors find a promising future in the area of wastewater treatment as one of the advanced oxidation methods. The obvious advantage of these processes is based on the fact that reactions can be carried out under ambient global conditions, which would otherwise require application of rigorous conditions, such as high temperature and pressure (wet air oxidation and /or . Incineration). The underlying mechanism for the spectacular effect observed due to ultrasonic irradiation is the cavitation phenomena, which can be defined as formation, growth and subsequent violent collapse of microbubbles or cavities, resulting in the generation of extremely high temperatures and pressures locally but at millions of such locations in the reactor. The violent collapse of the cavities also results in the formation of reactive hydrogen atoms and hydroxyl radicals, which combine to form hydrogen peroxide to some extent and are responsible for promoting oxidation reactions, which are mainly responsible for the destruction of the majority of the toxic compounds. Different Sonochemical reactors are available for industrial wastewater treatment such as ultrasonic horn, ultrasonic bath, dual frequency flow cell and triple frequency flow cell.