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Gallic acid water ozonation using activated carbon

Paper ID Volume ID Publish Year Pages File Format Full-Text
48885 46525 2006 11 PDF Available
Title
Gallic acid water ozonation using activated carbon
Abstract

The ozonation of gallic acid in water in the presence of activated carbon has been studied at pH 5. Hydrogen peroxide, ketomalonic and oxalic acids were identified as by-products. The process involves two main periods of reaction. The first period, up to complete disappearance of gallic acid, during which ozonation rates are slightly improved by the presence of activated carbon. The second one, during which activated carbon plays an important role as promoter, and total mineralization of the organic content of the water is achieved. The organic matter removal is due to the sum of contributions of ozone direct reactions and adsorption during the first period and to a free radical mechanism likely involving surface reactions of ozone and hydrogen peroxide on the carbon surface during the second period. There is a third transition period where by-products concentration reach maximum values and ozonation is likely due to both direct and free radical mechanisms involving ozone and adsorption. Discussion on the mechanism and kinetics of the process is also presented both for single ozonation and activated carbon ozonation.

Keywords
Activated carbon; Ozone; Gallic acid; Ozonation by-products; Heterogeneous activated carbon ozonation; Water ozonation
First Page Preview
Gallic acid water ozonation using activated carbon
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis B: Environmental - Volume 63, Issues 3–4, 31 March 2006, Pages 249–259
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis