Publication Details |
| Category | Text Publication |
| Reference Category | Qualification assignments |
| Document | publication document |
| Title (Primary) | Degradation of perfluoroalkyl acids using zeolites. Abbau von Perfluoralkylsäuren unter Verwendung von Zeolithen |
| Author | Qian, L. |
| Source Titel | PhD Dissertation |
| Year | 2021 |
| Department | TUCHEM |
| Volume | 12/2021 |
| Page To | 157 |
| Language | englisch |
| Topic | T7 Bioeconomy |
| Keywords | perfluorooctanoic acid; perfluorooctanesulfonic acid; Fe-zeolites; zeolite adsorption; degradation; UV-A; heterogeneous photochemistry; heat-activated persulfate; Trap & treat principle; cost estimation |
| UFZ inventory | Leipzig, Bibliothek, Berichtsammlung, 00540155, 21-0295 F/E |
| Abstract | The present thesis is aiming at developing novel techniques for treating perfluoroalkyl acids (PFAAs) in water. It is a huge challenge to treat PFAAs in aqueous environment due to their low concentrations (ng L-1 to μg L-1) and high resistance to biological and chemical degradation. To tackle this challenge, combining pre-enrichment and degradation processes can provide promising solutions. Three different pathways were studied in the present thesis to treat PFAAs after pre-enrichment on zeolites. A novel photochemical degradation approach of perfluorooctanoic acid (PFOA) under UV-A irradiation after adsorption on Fe-doped zeolites with molecular oxygen as the terminal oxidant has been established for the first time. Zeolite-bound iron species were proposed to offer catalytic sites for carboxylate-to-metal charge transfer activated by UV-A as initial step of PFOA degradation. The Fe-zeolite photocatalytic system was further applied for the even more resistant perfluorooctanesulfonic acid (PFOS). After adsorption on Fe-zeolite, UV-C irradiation was required to trigger its photochemical degradation and fully mineralize the short-chain byproducts after introduction of sodium persulfate. The activation of sodium persulfate can be alternatively achieved by heat to treat PFOA pre-loaded on BEA zeolites. A complete PFOA mineralization was realized in the presence of zeolites. The effects of reaction conditions, such as reaction pH and coexisting inorganic ions were investigated for all three established systems as well as the long-term stability. The Fe-zeolite photocatalytic system designed for PFOS and heat-activated persulfate/zeolite system for PFOA were successfully applied to real ground water samples containing trace-level PFAAs. These findings of the thesis provide efficient strategies for treatment of water containing highly recalcitrant trace amounts of PFAAs, which can inspire remediation techniques for water contaminated by other micropollutants as well. |
| Persistent UFZ Identifier | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=25490 |
| Qian, L. (2021): Degradation of perfluoroalkyl acids using zeolites. Abbau von Perfluoralkylsäuren unter Verwendung von Zeolithen Dissertation, Universität Leipzig, Fakultät für Chemie und Mineralogie PhD Dissertation 12/2021 Helmholtz-Zentrum für Umweltforschung - UFZ, Leipzig, 157 pp. |
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