An investigation of homogeneous and heterogeneous sonochemistry for the destruction of hazardous substances. Progress report, 1996--1997

'The primary objective of this research project is to acquire a deeper fundamental knowledge of acoustic cavitation and cavitation chemistry, and in doing so, to ascertain how ultrasonic irradiation can be more effectively applied to environmental problems. Four on-going projects will be described in this progress report, The first project is the destruction of carbofuran in a Near-Field Acoustical Processor (NAP), and the hydrodynamic characterization of the reactor. The second project is a comprehensive study of how ultrasonic frequency influences sonochemical reaction rates; the substrate it, the preliminary portion of this study has been hydrogen peroxide formation. The third project in progress is destruction of four polychlorinated biphenyls at 20 kHz. Work so far has been at 20 kHz, but the most significant portion of this project will involve a multi-frequency (ultrasonic frequency) study. Finally, the destruction of a pesticide, dichlorvos, during sonication at 500 kHz will be described. Preliminary work during the first year has emphasized determination of kinetics; further work (years 2--3) will be focused upon closing mass balances and identifying transformation products.