Science Inventory

HYDROXYL RADICAL/OZONE RATIOS DURING OZONATION PROCESSES. I. THE RCT CONCEPT

Citation:

Elovitz*, M S. AND U. von Gunten. HYDROXYL RADICAL/OZONE RATIOS DURING OZONATION PROCESSES. I. THE RCT CONCEPT. B.L. Loeb (ed.), OZONE SCIENCE AND ENGINEERING. Taylor and Francis, Philadelphia, PA, 21(3):239-260, (1999).

Impact/Purpose:

information

Description:

The ozonation of model systems and several natural waters was examined in bench-scale batch experiments. In addition to measuring the concentration of ozone (03), the rate of depletion of an in situ hydroxyl radical probe compound was monitored, thus providing information on the transient steady-state concentration of hydroxyl radials (*OH). A new parameter, Rct, representing the ratio of the *OH-exposure to the O3-exposure was calculated as a function of reaction time. For most waters tested, including pH-buffered model systems and natural waters, Rct was a constant value for the majority of the reaction. Therefore, Rct corresponds to the ratio of the *OH concentration to the O3 concentration in a given water (i.e. Rct= {*OH}/{03}). For a given water source, the degradation of a micropollutant (e.g. atrazine or chlorinated solvents) via O3 and *OH reaction pathways can be predicted by the O3 reaction kinetics and Rct.

URLs/Downloads:

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Record Details:

Record Type: DOCUMENT (JOURNAL/PEER REVIEWED JOURNAL)
Product Published Date: 01/01/1999
Record Last Revised: 11/19/2008
OMB Category: Other
Record ID: 111709

Organization:

U.S. ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF RESEARCH AND DEVELOPMENT

NATIONAL RISK MANAGEMENT RESEARCH LABORATORY

WATER SUPPLY AND WATER RESOURCES DIVISION

TREATMENT TECHNOLOGY EVALUATION BRANCH