Destruction of Rhodamine B using novel sonochemical reactor with capacity of 7.5 l

Abstract

Sonochemical reactors offer excellent promise in the wastewater treatment applications due to the creation of local hotspots with overall ambient operating conditions and release of highly reactive free radicals. However, its application in the actual industrial practice is hampered by the fact that the existing available information related to the optimization of operating parameters is restricted mainly to small scale operations with reported experiments with capacity in the range of few milliliters to 1 l. With this information, efficient scale up and successful operation of industrial scale reactors is almost impossible. Thus, design of novel large-scale sonochemical reactors and subsequent testing of the same for destruction of different pollutants is the need of the present hour. In an attempt to move one step ahead in the design process, a novel sonochemical reactor with a capacity of 7.5 l has been developed and tested using destruction of Rhodamine B as a model reaction. Effect of various operating parameters such as frequency of irradiation, use of multiple frequencies and power dissipation into the system on the extent of degradation has been studied. Experiments have also been performed with the KI decomposition (model reaction typically used in investigating cavitational effects) so as to establish the dependency of the trends in the variation of the extent of degradation with the operating parameters on the cavitational intensity requirements for a specific application. For the degradation of Rhodamine B, power dissipation into the system was found to be the controlling parameter and the extent of degradation is directly proportional to the power dissipation with a coefficient of 74.1.