Publication Details |
| Category | Text Publication |
| Reference Category | Journals |
| DOI | 10.1016/j.envpol.2025.127491 |
Licence  |
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| Title (Primary) | Contrasting release of redox-sensitive arsenic and uranium induced by heterotrophic denitrification in alluvial sediments |
| Author | Nitzsche, K.N.; Richard-Cerda, J.C.
; Ullrich, C.; Bigalke, M.; Schulz, S. |
| Source Titel | Environmental Pollution |
| Year | 2026 |
| Department | CATHYD |
| Volume | 390 |
| Page From | art. 127491 |
| Language | englisch |
| Topic | T5 Future Landscapes |
| Supplements | Supplement 1 |
| Keywords | Agricultural site; Incubation experiment; Nitrate; Sequential extraction; Shallow groundwater; Trace elements |
| Abstract | Arsenic
(As) and uranium (U) are toxic trace elements and can contaminate
groundwater. Elevated As and U concentrations exceeding the WHO drinking
water guideline values were found within the capillary fringe and
shallow groundwater at an agricultural site in the Hessian Ried,
Germany. The elevated U concentrations can be attributed to the
nitrate-triggered roll-front release of geogenic U in the redoxcline,
while the elevated As concentrations are associated with the reductive
dissolution of Fe-Mn oxyhydroxides at greater depth. To investigate the
release of these elements and specifically the role of nitrate, we
conducted a 90-day incubation experiment of the alluvial sediments in an
inert atmosphere (N2) glovebox. Mesocosms amended with nitrate (220 mg L−1)
and without nitrate were incubated in triplicates. In the control
mesocosms, we observed a progressive decline in Eh, accompanied by the
release of Mn and Fe due to reductive dissolution of (oxyhydr)oxides,
which led to a release of As. In contrast, in the nitrate-amended
mesocosms, heterotrophic denitrification caused (sub)oxic conditions,
which inhibited the reductive dissolution of (oxyhydr)oxides, but led to
the oxidative release of U. Sequential and single extractions showed
that the geochemical fractions of U did not change and that about 93 %
occurred as reduced U(IV) before and after the experiment. Our findings
suggest that agricultural inputs of nitrate can cause the release of
geogenic U, while simultaneously reducing the reductive release of As. |
| Persistent UFZ Identifier | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=31723 |
| Nitzsche, K.N., Richard-Cerda, J.C., Ullrich, C., Bigalke, M., Schulz, S. (2026): Contrasting release of redox-sensitive arsenic and uranium induced by heterotrophic denitrification in alluvial sediments Environ. Pollut. 390 , art. 127491 10.1016/j.envpol.2025.127491 |
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