at Google ScholarTitle data
Metz, Rouven ; Kumar, Naresh ; Schenkeveld, Walter D. C. ; Obst, Martin ; Voegelin, Andreas ; Mangold, Stefan ; Kraemer, Stephan M.:
Effect of Oxidation on Vivianite Dissolution Rates and Mechanism.
In: Environmental Science & Technology.
Vol. 58
(2024)
Issue 34
.
- pp. 15321-15332.
ISSN 0013-936X
DOI: https://doi.org/10.1021/acs.est.4c04809
Abstract in another language
The interest in the mineral vivianite (Fe3(PO4)2·8H2O) as a more sustainable P resource has grown significantly in recent years owing to its efficient recovery from wastewater and its potential use as a P fertilizer. Vivianite is metastable in oxic environments and readily oxidizes. As dissolution and oxidation occur concurrently, the impact of oxidation on the dissolution rate and mechanism is not fully understood. In this study, we disentangled the oxidation and dissolution of vivianite to develop a quantitative and mechanistic understanding of dissolution rates and mechanisms under oxic conditions. Controlled batch and flow-through experiments with pristine and preoxidized vivianite were conducted to systematically investigate the effect of oxidation on vivianite dissolution at various pH-values and temperatures. Using X-ray absorption spectroscopy and scanning transmission X-ray microscopy techniques, we demonstrated that oxidation of vivianite generated a core–shell structure with a passivating oxidized amorphous Fe(III)–PO4 surface layer and a pristine vivianite core, leading to diffusion-controlled oxidation kinetics. Initial (<1 h) dissolution rates and concomitant P and Fe release (∼48 h) decreased strongly with increasing degree of oxidation (0–≤ 100%). Both increasing temperature (5–75 °C) and pH (5–9) accelerated oxidation, and, consequently, slowed down dissolution kinetics.
Further data
| Item Type: | Article in a journal |
|---|---|
| Refereed: | Yes |
| Keywords: | Mineral Transformation; Oxidation Kinetics; Core–Shell Structure; Metastability; Amorphous Iron Phosphate; Santabarbaraite |
| Institutions of the University: | Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Earth Sciences > Heisenberg Professorship - Experimental Biogeochemistry > Heisenberg Professorship - Experimental Biogeochemistry - Univ.-Prof. Dr. Martin Obst |
| Result of work at the UBT: | Yes |
| DDC Subjects: | 500 Science > 550 Earth sciences, geology |
| Date Deposited: | 15 Oct 2024 07:34 |
| Last Modified: | 15 Oct 2024 07:34 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/90689 |