Effect of cysteine using Fenton processes on decolorizing different dyes : a kinetic study
Amino acid cysteine has been used as reducing mediator with the aim of improving dye degradation by homogeneous Fenton processes (Fe2+/H2O2 and Fe3+/H2O2). Through its known Fe3+-reducing activity, this amino acid can enhance the production of reactive oxygen species as HO• (hydroxyl radical) and it...
| Veröffentlicht in: | Environmental technology. - 1993. - 43(2022), 1 vom: 06. Jan., Seite 70-82 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2022
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| Zugriff auf das übergeordnete Werk: | Environmental technology |
| Schlagworte: | Journal Article Fenton reaction cysteine dye hydroxyl radical kinetic Coloring Agents Hydrogen Peroxide BBX060AN9V Iron mehr... |
| Zusammenfassung: | Amino acid cysteine has been used as reducing mediator with the aim of improving dye degradation by homogeneous Fenton processes (Fe2+/H2O2 and Fe3+/H2O2). Through its known Fe3+-reducing activity, this amino acid can enhance the production of reactive oxygen species as HO• (hydroxyl radical) and its pro-oxidant properties have been verified while decolorizing diverse dyes in the present work. Its presence enhanced decolorization of Methyl Orange, Phenol Red, Safranin T, Rhodamine B, Reactive Black 5 and Reactive Yellow 2, mainly in reactions initially containing Fe3+ as a catalyst (Fe3+-reactions). E.g. Fe3+/H2O2 and Fe3+/H2O2/cysteine systems decolorized 27% and 44% of Phenol Red after 60 min, respectively. A kinetic modeling analysis has revealed that 1st-order and mainly 2nd-order kinetic models were well fitted to both Fe2+- and Fe3+-reactions data. Improvements in reaction rate constants have been observed by adding cysteine. In experiments performed at varied temperatures, it was found a decrease in activation energy (Ea) due to cysteine addition while decolorizing Safranin T: Ea decreased from 104.6 to 88.9 kJ mol-1 for Fe3+-reactions and from 81.0 to 52.2 kJ mol-1 for Fe2+-reactions. Therefore, it was found that cysteine decreases the energy barrier so as to improve Fenton-based decolorization reactions |
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| Beschreibung: | Date Completed 20.01.2022 Date Revised 20.01.2022 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1479-487X |
| DOI: | 10.1080/09593330.2020.1776402 |