Efficient removal of 3,6-dichlorocarbazole with Fe0-activated peroxymonosulfate : performance, intermediates and mechanism
Nowadays, polyhalogenated carbazoles (PHCZs) are a major pollutant that has recently sparked widespread concern. In this work, peroxymonosulfate (PMS) was activated by zero valent iron (Fe0) to remove 3,6-dichlorocarbazole (3,6-CCZ). First, the key parameters influencing 3,6-CCZ degradation (PMS dos...
| Publié dans: | Environmental technology. - 1993. - 44(2023), 15 vom: 13. Juni, Seite 2201-2214 |
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| Auteur principal: | |
| Autres auteurs: | , , , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2023
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| Accès à la collection: | Environmental technology |
| Sujets: | Journal Article 3,6-Dichlorocarbazole(3,6-CCZ) degradation pathways mechanism peroxymonosulfate (PMS) radical identification peroxymonosulfate 22047-43-4 3,6-dichlorocarbazole Reactive Oxygen Species plus... |
| Résumé: | Nowadays, polyhalogenated carbazoles (PHCZs) are a major pollutant that has recently sparked widespread concern. In this work, peroxymonosulfate (PMS) was activated by zero valent iron (Fe0) to remove 3,6-dichlorocarbazole (3,6-CCZ). First, the key parameters influencing 3,6-CCZ degradation (PMS dosage, Fe0 dosage, initial pH, temperature and co-existing ions) were determined. Under the determined optimum conditions, the removal rate of 3,6-CCZ reached 100% within 1.5 h. Sulfate radicals (SO4·-), hydroxyl radicals (OH·), and singlet oxygen (1O2) generated in the reaction were directly identified with 0.1 M 5,5-dimethyl-1-pyrrolidine N-oxide (DMPO) by in-situ electron paramagnetic resonance (EPR) and indirectly identified by radical quenching experiments. The main reactive oxygen species (ROS) were different from most reported hydroxyl radicals (OH·) and sulfate radicals (SO4·-). In this study, it was found that OH· and 1O2 play a major role. Then, fresh and reacted Fe0 were characterized by XRD, SEM, and XPS. Iron corrosion products such as Fe2O3, Fe3O4, and FeOOH were generated. Finally, 3,6-CCZ degradation intermediates were identified by GC-MS and its degradation pathway was speculated. The intermediate pathway confirmed the combined action of (OH·) and (1O2) in 3,6-CCZ removal. This study provides new insight into the activation mechanism of Fe0-activated PMS and the removal mechanism of 3,6-CCZ.Highlights Fe0 is a long-lasting and efficient catalyst of PMS for the degradation of 3,6-CCZ.The key parameters influencing 3,6-CCZ degradation were determined.The degradation pathways of 3,6-CCZ were inferred.OH· and 1O2 were the main ROS in Fe0-activated PMS system |
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| Description: | Date Completed 05.06.2023 Date Revised 05.06.2023 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1479-487X |
| DOI: | 10.1080/09593330.2021.2024888 |