Oxone/Fe2+ Degradation of Food Dyes: Demonstration of Catalyst-Like Behavior and Kinetic Separation of Color

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• 作者：Ruth E. Nalliah
• 刊名：Journal of Chemical Education
• 出版年：2015
• 出版时间：October 13, 2015
• 年：2015
• 卷：92
• 期：10
• 页码：1681-1683
• 全文大小：150K
• ISSN：1938-1328

文摘

A demonstration of the degradation of food coloring dyes by oxidation via the Fenton reaction can be substituted with a simpler demonstration using the oxidant oxone with iron(II) ions as an activator. The addition of small amounts of solid oxone and iron(II) sulfate to solutions containing mixtures of food coloring results in successive degradation of food dyes within minutes, also showing a kinetic separation of color. Because food dyes of different colors degrade at different rates, successive changes in color during degradation can be observed for various dye mixtures. Catalyst-like behavior is also demonstrated; in the absence of a transition metal such as iron to activate the oxone, negligible color degradation is observed within the time frame of the demonstration. The demonstration presents an opportunity to introduce topics such as structural characteristics of organic chromophores, the catalyst-like behavior of a transition metal, the practical importance of chemical kinetics, and challenges involved in finding eco-friendly methods of efficiently oxidizing pollutants, including not only waste dyes but also personal care products and excreted pharmaceuticals.