Kinetics and Mechanism of Pentachlorophenol Degradation by Sonication, Ozonation, and Sonolytic Ozonation
Abstract
The decomposition of pentachlorophenol (PCP) by sonication was investigated at two frequencies (20 and 500 kHz) and two concentrations (20 and 60 μM) to gain insight into the kinetics and mechanisms occurring at different frequencies. Results suggest the presence of parallel pyrolysis and OH• reaction pathways that are altered both as a function of frequency and PCP concentration. In addition, ozone was added to the system and compared to experiments of sonication and ozonation separately to explore the mechanism of sonolytic ozonation. The addition of ozone during sonication did not affect the first-order degradation constant for PCP compared to the linear combination of separate sonication and ozonation experiments; hence, the residual kinetic effect of the combined system was zero (k_(US/O_3) = 0). Observed byproducts of sonication include the following: tetrachloro-o-benzoquinone (o-chloranil), tetrachlorocatechol (TCC), oxalate, and chloride.
Additional Information
© 2000 American Chemical Society. Received for review August 4, 1998. Revised manuscript received April 23, 1999. Accepted December 16, 1999. Publication Date (Web): February 16, 2000. The authors wish to thank Anne Johansen and Peter Green for help with analysis of intermediates. Financial support provided by Defense Advanced Research Projects Agency (DARPA), Office of Naval Research (ONR), the Electrical Power Research Institute (EPRI), and the Department of Energy (DOE) is gratefully acknowledged.Additional details
- Eprint ID
- 59453
- DOI
- 10.1021/es980795y
- Resolver ID
- CaltechAUTHORS:20150812-143042805
- Defense Advanced Research Projects Agency (DARPA)
- Office of Naval Research (ONR)
- Electric Power Research Institute (EPRI)
- Department of Energy (DOE)
- Created
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2015-08-13Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field