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Hellings, L.; Driessche, K. Van den; Baeyens, Willy; Keppens, Eddy; Dehairs, Frank

doi:10.1023/a:1006472213070

Cited by 31 publications

(4 citation statements)

References 24 publications

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“…Methanogenesis is therefore expected to be an important degradation process in organic-rich, freshwater sediments, such as the ones studied here (Middelburg et al 1995;Van der Nat et al 1998;Van der Nat and Middelburg 2000;Hellings et al 2000). The low rates of CH 4 release from the unamended reactors are thus somewhat surprising.…”

Section: Dic Release By Caco 3 Dissolution Iron Reduction and Methanmentioning

confidence: 88%

Bioavailability of organic matter in a freshwater estuarine sediment: long-term degradation experiments with and without nitrate supply

2009

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Organic carbon degradation experiments were carried out using flow-through reactors with sediments collected from an intertidal freshwater marsh of an eutrophic estuary (The Scheldt, Belgium). Concentrations of nitrate, nitrite, dissolved inorganic carbon (DIC), dissolved organic carbon, methane, dissolved cations (Ca 2? , Mg 2? , Na ? and K ? ), total dissolved Fe, phosphate and alkalinity were measured in the outflow solutions from reactors that were supplied with or without the terminal electron acceptor nitrate. Organic carbon mineralization rates were computed from the release rates of DIC after correcting for the contribution of carbonate mineral dissolution. The experiments ran for several months until nitrate reducing activity could no longer be detected. In the reactors supplied with nitrate, 10-13% of the bulk sedimentary organic carbon (SOC) was mineralized by the end of the experiments. In reactors receiving no nitrate, only 3-9% of the initial SOC was mineralized. Organic matter utilization by nitrate reducers could be described as the simultaneous degradation of two carbon pools with different maximum oxidation rates and half-saturation constants. Even when nitrate was supplied in non-limiting concentrations about half of the carbon mineralization in the reactors was due to fermentative processes, rather than being coupled to nitrate respiration. Fermentation may thus be responsible for a large fraction of the DIC efflux from organic-rich, nearshore sediments.

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Section: Dic Release By Caco 3 Dissolution Iron Reduction and Methanmentioning

confidence: 88%

Bioavailability of organic matter in a freshwater estuarine sediment: long-term degradation experiments with and without nitrate supply

2009

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“…The IC concentrations, however, kept increasing up to the 10th month ( Fig. 1), probably due to the dissolution of CO 2 produced during organic matter decomposition (Hellings et al 2000;van den Berg and Loch 2000). They also substantially increased below the water table, towards peaks between 400 and 600 mg L −1 in Kijkverdriet, Bornem and Konkelschoor.…”

Section: Dissolved Carbon Sulphate and Major Elementsmentioning

confidence: 96%

Effect of Water Table Level on Metal Mobility at Different Depths in Wetland Soils of the Scheldt Estuary (Belgium)

Laing

Meers

Dewispelaere

et al. 2009

Water Air Soil Pollut

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An experiment was set up to assess the factors affecting metal mobility in five wetland soils of the Scheldt estuary at different sampling depths when subjecting the soils to various water table levels. Pore water metal concentrations were monitored for 10 months at four sampling depths (10, 30, 60 and 90 cm) upon adjusting the water table level to 0, 40 and 80 cm below the surface of the soils. Nickel (Ni) release is facilitated by reductive conditions. These reductive conditions mainly occur below the water table. The fate of chromium (Cr) under reductive conditions seems to be promoted by the presence of dissolved organic matter. However, Cr fate seems to be inconsistent between the soils, as it is affected by a series of counteracting mechanisms. Copper (Cu), zinc (Zn) and especially cadmium (Cd) are all primarily released above the water table under high salinity conditions. These elements are also released below or just above the water table when organic matter is being decomposed, resulting in calcium (Ca), manganese (Mn), Ni and/or iron (Fe) release upon CO 2 accumulation and Fe/Mn oxide reduction, without being accompanied by sulphide production. Their mobility is low under reducing conditions, i.e. in the presence of sulphides, whereas the complexation by soluble organic matter especially seems to promote Cu mobility.

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“…The δ 13 C value of CO 2 and DIC in fresh spring and groundwaters is generally derived during recharge from the soil, followed by dissolution, associated isotope fractionation (see section ) and weathering of carbonate material . Bacterial action can isotopically enrich DIC in 13 C (up to +30‰), via reduction of CO 2 to methane (Figure ), or fermentation of acetate to produce CH 4 and CO 2 . − …”

Section: Baseline Fingerprint Of Leakage Pathway Reservoirs (Atmosphe...mentioning

confidence: 99%

Inherent Tracers for Carbon Capture and Storage in Sedimentary Formations: Composition and Applications

Flude

Johnson

Gilfillan

et al. 2016

Environ. Sci. Technol.

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Inherent tracers-the "natural" isotopic and trace gas composition of captured CO2 streams-are potentially powerful tracers for use in CCS technology. This review outlines for the first time the expected carbon isotope and noble gas compositions of captured CO2 streams from a range of feedstocks, CO2-generating processes, and carbon capture techniques. The C-isotope composition of captured CO2 will be most strongly controlled by the feedstock, but significant isotope fractionation is possible during capture; noble gas concentrations will be controlled by the capture technique employed. Comparison with likely baseline data suggests that CO2 generated from fossil fuel feedstocks will often have δ(13)C distinguishable from storage reservoir CO2. Noble gases in amine-captured CO2 streams are likely to be low concentration, with isotopic ratios dependent on the feedstock, but CO2 captured from oxyfuel plants may be strongly enriched in Kr and Xe which are potentially valuable subsurface tracers. CO2 streams derived from fossil fuels will have noble gas isotope ratios reflecting a radiogenic component that will be difficult to distinguish in the storage reservoir, but inheritance of radiogenic components will provide an easily recognizable signature in the case of any unplanned migration into shallow aquifers or to the surface.

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Untitled

Cited by 31 publications

References 24 publications

Bioavailability of organic matter in a freshwater estuarine sediment: long-term degradation experiments with and without nitrate supply

Bioavailability of organic matter in a freshwater estuarine sediment: long-term degradation experiments with and without nitrate supply

Effect of Water Table Level on Metal Mobility at Different Depths in Wetland Soils of the Scheldt Estuary (Belgium)

Inherent Tracers for Carbon Capture and Storage in Sedimentary Formations: Composition and Applications

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