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Published September 15, 1998 | public
Journal Article

Aromatic Compound Degradation in Water Using a Combination of Sonolysis and Ozonolysis

Abstract

The combination of sonolysis and ozonolysis as an advanced oxidation process was investigated to gain insight into factors affecting enhancement of the combined system. Sonolysis, ozonolysis, and a combination of the two were used to facilitate the degradation of three known organic contaminants, nitrobenzene (NB), 4-nitrophenol (4-NP), and 4-chlorophenol (4-CP), in water. Experiments were performed at frequencies of 20 and 500 kHz. At 20 kHz, there appeared to be an enhancement due to sonolytic ozonation, while at 500 kHz, an apparent retardation was seen. The catalytic effects of NB, 4-NP, and 4-CP degradation at 20 kHz increased with decreasing k_(O_3) of the compounds, whereas retardation at 500 kHz was correlated with increasing k_(O_3). The correlation of apparent rate enhancement at 20 kHz and retardation at 500 kHz with k_(O_3) is consistent with a pathway involving the thermolytic destruction of ozone to form atomic oxygen. Atomic oxygen then reacts with water vapor in cavitation bubbles, yielding gas-phase hydroxyl radical. Enhancement in loss of total organic carbon (TOC) by sonolytic ozonation was considerable at both 20 and 500 kHz with all three compounds. In addition, intermediate product formation was observed.

Additional Information

© 1998 American Chemical Society. Received for review July 31, 1997. Revised manuscript received June 16, 1998. Accepted June 20, 1998. Publication Date (Web): August 13, 1998. Financial support provided by Defense Advanced Research Projects Agency (DARPA), the Office of Naval Research (ONR), the Electric Power Research Institute (EPRI), and the Department of Energy (DOE) is gratefully acknowledged.

Additional details

Created:
August 19, 2023
Modified:
October 23, 2023