Impact of CO2 leakage from sub-seabed carbon dioxide …
The geochemical composition of the porewater in the upper 430 cm of the sediments prior to the CO 2 injection is similar to that reported previously from the area (Dale et al., 2021) with dissolved Ca, Sr, Li, K and Mg concentrations similar to seawater (i.e., 10 mM, 75 µM, 25 µM, 8.5 mM and 50 mM); dissolved iron <1 µM and dissolved …
Biogenic silica in freshwater marsh sediments and …
Porewater dissolved Si was highest in summer (ca. 600 µM) and lowest in winter (ca. 400 µM). ... amount of dissolved silica (DSi) that is transported to coastal waters through estuaries is essential for the occurrence of eutrophication events in the coastal zone. In contrast to N and P, with large human inputs through river
Mechanisms and magnitude of dissolved silica release
Porewater (marsh) dissolved silica (DSi) depth profiles from the Sage Lot Pond marsh. DSi depth profiles indicate that surface (depth < 30 cm) samples vary considerably across time, while DSi in ...
Fate and Effect of Dissolved Silicon within Wastewater …
In large rivers, the ratios of silicon (Si)/nitrogen (N)/phosphorus (P) have changed dramatically as anthropogenic additions of N or P are not matched by Si. Wastewater effluent is a recognized source of N and P to coastal environments. Few previous studies, however, have examined the Si load of a large wastewater plant's …
Biogenic silica dissolution in sediments of the …
In sediments that experience a significant detrital input, the simultaneous reprecipitation of dissolved aluminum and dissolved silica prevents pore water silicic …
Natural and human influences on dissolved silica export …
Natural and human factors controlling dissolved silica (DSi) export from the watershed were investigated for the Jiulong River watershed in Southeast China, which is a subtropical region where tectonic activity and high runoff combine to create a global hot spot for DSi flux. Results showed that river DSi was fairly high (246 ± 76 µmol L−1) due to …
An occurrence density plot of modern marine …
Download scientific diagram | An occurrence density plot of modern marine porewater dissolved silica levels The plot is based on dissolved silica concentrations (n = 6,245) from 453 sediment cores ...
Mechanisms and magnitude of dissolved silica …
Porewater (marsh) dissolved silica (DSi) depth profiles from the Sage Lot Pond marsh. DSi depth profiles indicate that surface (depth < 30 cm) samples vary considerably across time, while DSi in deeper porewater is around 150 μM. See more
Climate change effects on peatland decomposition and porewater …
Carbon accumulation and storage is a defining characteristic of peatland ecosystems. Decomposition of peat releases dissolved organic carbon (DOC) to receiving waters and can be an important fraction of the peatland carbon budget, along with being an important modifier of downstream water quality. Changes in temperature and …
Soil Pore Water Sampling Methods
Soil pore water contains solutes, dissolved gases, and particulate materials. Determination of pore water solutes requires separation of the solid from the liquid phase. For gases, further separation of the gas from the liquid phase is necessary. Pore water sampling methods can be grouped into three general categories: (i) forcing …
Dissolved silica (DSi) vs salinity in porewater …
Download scientific diagram | Dissolved silica (DSi) vs salinity in porewater (marsh), brackish subterranean estuary and groundwater. The mixing line between the estuarine tidal creek and ...
Mechanisms and magnitude of dissolved silica …
To do this, we measured DSi concentrations in the tidal creek of a temperate salt marsh across 13 tidal cycles seasonally (spring, summer, fall) for three years and quantied DSi …
Active Silica Diagenesis in the Deepest Hadal …
Abstract. Porewater dissolved silicic acid (DSi) concentrations and stable Si isotope compositions (δ 30 Si) together with biogenic silica (bSiO 2) contents of sediments in five sediment cores …
Frontiers | Porewater exchange drives the dissolved …
Silicon (Si) as a vital biogenic element affects plant growth and health of coastal ecosystems. The understanding of key factors and processes controlling …
Global Biogeochemical Cycles
Porewater profiles of the major nutrients dissolved silica (DSi), dissolved inorganic nitrogen (DIN), and dissolved inorganic …
Porewater exchange drives the dissolved silicate export …
DSi export across the wetland‐estuarine continuum was largely controlled by porewater exchange, groundwater geochemistry (pH, temperature) and plant root uptake. Groundwater in the mangroves has ...
Silica: An essential nutrient in wetland biogeochemistry
Wetland plants take up dissolved Si (DSi) from the soil or water to increase their rigidity and survival chances, which accumulate as biogenic silica (BSi) in plant tissues (Schoelynck et al., 2010).
The Silicon Cycle
The primary source of dissolved silica in aquatic environments is the weathering of rock-forming silicate minerals by acidic dissolution. ... Depth dependence of dissolved silica (DSi) in porewater of sediment from the North Atlantic, the Equatorial Pacific, and the Southern oceans. The lines represent the best fit by a diagenetic …
Silica storage in a riparian wetland
25 of dissolved silica (DSi), and the eventual export to the aquatic environment. Biogenic ... and porewater DSi were taken at 17 sampling sites along 4 gradients perpendicular
dissolved silica porewater
The exchange of dissolved substances between the porewater and overlying seawater that results is an important process in the context of the biogeochemistry of the oceans.A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance.
Silica fluxes and trapping in two contrasting natural
Human activities have altered riverine silica cycling and diminished the supply of silica to the oceans, but few rivers have been intensively monitored to evaluate the magnitude of these changes. In this study we measured dissolved silica (DSi) and amorphous silica (ASi) fluxes into and out of two large, culturally-impacted natural …
Outwelling of reduced porewater drives the …
Aged porewater input results in enhanced pCO 2 and CH 4 concentrations in the water column during spring compared to neap tide in the Caeté estuary (Call et al. 2019). We found lower dissolved …
Porewater
7.03.3.2.1 Pore-water chemistry. The chemistry of sediment pore waters provides important information regarding chemical reactions in sediments. In many cases, the reactions between pore waters and solids are not obvious from observations of the solids alone, but because the solid-to-solution ratio in sediments is so large, major changes can ...
Mechanisms and magnitude of dissolved silica …
Ge/Si ratios in the porewater, subterranean estuary, and fresh groundwater averaged 6.3 ± 0.31 µmol/mol, which is consistent with production via silicate weathering rather than …
The ebb and flood of Silica: Quantifying dissolved and biogenic silica
Found at the land–sea interface, these systems are silica replete with large stocks in plant biomass, sediments, and porewater, and therefore, have the potential to play a substantial role in the transformation and export of silica to coastal waters. In an effort to better understand this role, we measured the fluxes of dissolved (DSi) and ...
Sediment Pore Waters
Dissolved organic matter (DOM) in sediment pore waters is a heterogeneous collection of organic compounds, ranging in size from relatively large macromolecules (e.g., dissolved proteins or humic substances) to smaller molecules such as individual amino acids or short-chain organic acids. ... Benthic fluxes and porewater …
Silicon is the Link between Tidal Marshes and Estuarine …
Vascular plants remove silicate from porewater and deposit amorphous silica into cell walls where it remains until liberated by decomposition into surface water where it can again be taken up by diatoms. Drainage of porewater containing high concentrations of dissolved silicate from marsh sediments is very slow, so flux of dissolved silicate ...
Porewater exchange drives the dissolved
(2023) Porewater exchange drives the dissolved silicate export across the wetland‐estuarine continuum. Front. Mar. Sci. 10:1206776. ... silica fluxes caused by river damming, it is crucial to ...
Benthic fluxes and pore water studies from sediments of the …
Benthic exchange rates of radon-222, oxygen, nitrate, ammonia, and silica were determined using an in situ benthic flux chamber and by modeling pore water profiles at three sites in the central equatorial north Pacific. A comparison of these results reveals several artifacts of pore water collection and processing.
A comparison of four porewater sampling methods for …
Various methods for sampling porewater for trace metals and dissolved organic carbon (DOC), which is an important moderator of metal bioavailability, have been employed. The present study compares the peeper, push point, centrifugation, and diffusive gradients in thin films (DGT) methods for the quantification of 6 metals and DOC. ...
