Stability of alkalinity in the land-ocean transition zone
A geochemical CDR perspective for the Elbe River, Germany
Bibliographic Data
| ID | 15549673 |
|---|---|
| Authors | Mingyang Tian (0000-0003-2604-985X, Universität Hamburg, corresponding author), Jens Hartmann (0000-0003-1878-9321, Universität Hamburg), Niels Suitner (0000-0003-3413-857X, Universität Hamburg), Thorben Amann (0000-0001-9347-0615, Universität Hamburg), Stephan Kempe (0000-0001-5122-4272, Technische Universität Darmstadt), Carl Lim (0000-0002-9035-4771, Universität Hamburg), Charly A Moras (0000-0001-6819-6167, Universität Hamburg) |
| Year | 2025 |
| Volume | 20 |
| Issue | 9 |
| Pages | 094053-094053 |
| Publication date | 2025-07-11 |
| Peer Reviewed | Yes |
| Open Access | Yes |
| Type | ARTICLE |
| Venue | Environmental Research Letters (JOURNAL) |
| Journal identifiers | ISSN: 1748-9326 • E-ISSN: 1748-9326 |
| Publisher | IOP Publishing (PUBLISHER • GB) |
| DOI | 10.1088/1748-9326/adeeab |
| OpenAlex | W4412355450 |
| Language | EN |
| References cited | 42 |
Carbon dioxide removal (CDR) strategies like enhanced weathering and river/ocean alkalinity enhancement have been suggested to increase alkalinity in rivers, coastal areas, and eventually oceans. The effectiveness and sustainability of these CDR approaches depend on the persistence of added alkalinity, since exceeding certain Ω-thresholds for a given water composition may lead to carbonates formation, causing the loss of previously added alkalinity. In this research, stability of alkalinity was tested using incubation experiments with Elbe estuary freshwater from two seasons (March and August). Alkalinity was increased up to 4000 μ mol kgw −1 , with varying salinity from 0 to 16. This study shows that the stability of alkalinity depends on the presence and quantity of suspended particles, seasonality of water chemistry, and salinity. Based on the experimental data, the Elbe estuary may take up additional alkalinity in the freshwater part, corresponding to ∼3.0 MtCO 2 yr −1 being transported towards the North Sea. Estimates of alkalinity additions from the 1970s to 2010s show a decreasing potential due to changes in p CO 2 and pH. The upper geochemical limit for transporting additional alkalinity through estuarine systems serves as a critical boundary. Environmentally feasible levels may be lower than identified here and depend on environmental regulations
Alkalinity · Earth science · Geotechnical engineering · Hydrology (agriculture · Perspective (graphical · Chemistry · Environmental Science · Groundwater and Isotope Geochemistry · Geology · Oceanography
| Citation velocity | historical |
|---|---|
| Highly cited | No |