Uranium and thorium species in phosphate rock and sewage sludge ash based phosphorus fertilizers
- Phosphorus (P) is an essential element for all forms of life and is thus often applied as phosphate rock-based P-fertilizers in agriculture to enable continuous farming. However, these P-fertilizers contain also hazardous uranium (U) and thorium (Th), up to 660 and 220 mg/kg, respectively. On the contrary, novel P-fertilizers made from sewage sludge (ash) contain only low mass fractions of U and Th. In addition to the total amount of U and Th in P-fertilizers, their mobility and bioavailability is important, which depends to a large extent on their chemical state, especially oxidation state and chemical bonding. Thus, we analyzed their chemical state in various P-fertilizers by U and Th L3-edge HERFD-XANES spectroscopy. Phosphate rocks and sewage sludge-based P-fertilizers contain mainly U(IV) compounds which have only a low bioavailability. In contrast, acidic treatment of phosphate rock to produce super phosphates lead to an oxidation to U(VI) compounds (including formation ofPhosphorus (P) is an essential element for all forms of life and is thus often applied as phosphate rock-based P-fertilizers in agriculture to enable continuous farming. However, these P-fertilizers contain also hazardous uranium (U) and thorium (Th), up to 660 and 220 mg/kg, respectively. On the contrary, novel P-fertilizers made from sewage sludge (ash) contain only low mass fractions of U and Th. In addition to the total amount of U and Th in P-fertilizers, their mobility and bioavailability is important, which depends to a large extent on their chemical state, especially oxidation state and chemical bonding. Thus, we analyzed their chemical state in various P-fertilizers by U and Th L3-edge HERFD-XANES spectroscopy. Phosphate rocks and sewage sludge-based P-fertilizers contain mainly U(IV) compounds which have only a low bioavailability. In contrast, acidic treatment of phosphate rock to produce super phosphates lead to an oxidation to U(VI) compounds (including formation of uranium phosphates) with a strongly increased bioavailability. On the contrary, all analyzed P-fertilizers contain Th in form of strongly insoluble phosphates and oxides with a low bioavailability. Additionally performed water extractions and Diffusive Gradients in Thin-films (DGT) experiments support these findings.…
Autor*innen: | Christian VogelORCiD, Marie Hoffmann, Mareike Taube, O. Krüger, R. Baran, Christian AdamORCiD |
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Dokumenttyp: | Zeitschriftenartikel |
Veröffentlichungsform: | Verlagsliteratur |
Sprache: | Englisch |
Titel des übergeordneten Werkes (Englisch): | Journal of Hazardous Materials |
Jahr der Erstveröffentlichung: | 2020 |
Organisationseinheit der BAM: | 4 Material und Umwelt |
4 Material und Umwelt / 4.4 Thermochemische Reststoffbehandlung und Wertstoffrückgewinnung | |
Jahrgang/Band: | 382 |
Erste Seite: | 121100, 1 |
Letzte Seite: | 6 |
DDC-Klassifikation: | Naturwissenschaften und Mathematik / Chemie / Analytische Chemie |
Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Sanitär- und Kommunaltechnik; Umwelttechnik | |
Freie Schlagwörter: | Diffusive Gradients in Thin-films (DGT); Extraction; Phosphorus fertilizer; Sewage sludge; X-ray absorption near-edge structure (XANES) spectroscopy |
Themenfelder/Aktivitätsfelder der BAM: | Chemie und Prozesstechnik |
Umwelt | |
Umwelt / Circular Economy | |
DOI: | 10.1016/j.jhazmat.2019.121100 |
ISSN: | 0304-3894 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 06.09.2019 |
Referierte Publikation: | Ja |
Datum der Eintragung als referierte Publikation: | 06.09.2019 |