1. Introduction. Biogenic silica (BSi), which is mostly composed of diatom, radiolarian and sponge spicule remains, is a major biogenic component of marine sediments, and BSi-rich sediments occur at all depths, latitudes and climate zones of the world׳s oceans (Leinen et al., 1986, Mortlock et al., 1991, Ragueneau et al., …

incineration used in this study were: 1. Silica denoted as RHA-BG was prepared under. laboratory conditions at IGIC-BAS using rice. husk obtained in the region of Pazardzhik, thrashing 2010. The ...

The two-step procedure indicates that ∼90% of the biogenic silica originally present in deposits is converted to clay or otherwise altered, raising the effective quantity of biogenic silica stored from ∼33 to ∼296 μmol Si g −1 (∼1.8% SiO 2). Biogenic Si stored in the delta increases away from the river mouth, across shelf and along ...

Biogenic silica was transformed into dSi and measured with a UV-1600PC Spectrophotometer (Shimadzu, Japan) at a wavelength of 810 nm using 50 mm cuvettes. Cell suspensions (5 ml) were filtered through a 33 mm diameter 0.22 μm pore-size Millex-GP filter (Millipore, Ireland) and stored at −20°C to determine the concentration of dSi …

Silica nanostructures are promising carriers for a variety of applications in biological and material sciences. Currently, there is a growing interest in the extraction of silica nanostructures from agriculture by-product and waste. Here we investigate the extraction of nanostructured silica from olive stone using an alkali leaching extraction …

In addition, we present an updated value of the global annual pelagic biogenic silica production (255 Tmol Si yr−1) based on new data from 49 field studies and 18 model outputs, and we provide a …

Sciforum MDPI Books Preprints Scilit SciProfiles Encyclopedia JAMS Proceedings Series. About. Overview Contact Careers News Press Blog. Sign In / Sign Up. ... Dirk Enke, Thomas Schliermann, Volker Lenz, and Mehdi Bidabadi. 2019. "Generation of High Quality Biogenic Silica by Combustion of Rice Husk and Rice Straw Combined …

The burial efficiency of biogenic silica (BSi) in deltaic sediments is associated both with the nutrient balance in estuarine ecosystems and with the carbon cycle and climate change. To explore these relationships, foraminifera data, physical and chemical parameters, ...

Biogenic silica (bSi), also referred to as opal, biogenic opal, or amorphous opaline silica, forms one of the most widespread biogenic minerals. For example, microscopic particles of silica called phytoliths can be found in grasses and other plants. Silica is an amorphous metal oxide formed by compl

The role of plants in soil development has become of crucial interest in quantifying global weathering processes. On the volcanic Reunion Island (Indian Ocean), a 15-cm-thick phytolith-rich horizon (biogenic opal-A) developed at the expense of trachytic ashes between 3820 ± 85 and 335 ± 90 yr B.P. Then, 97–138 t/km 2 /yr of SiO 2 were ...

the measurement of biogenic silica (BSi) in sediments. Three modifications of thisbasic technique are commonly used: 1) A moderate strength base is used (2 M and the sample …

Biogenic silica (BSi) content in marine sediment can be considered as a good proxy to characterize the bio-productivity of the Southern Ocean [16,17]. However, the quantification of BSi is complicated by the presence of lithogenic silica, which is chemically equivalent to BSi (SiO 2 ), with the only difference being crystalline, while BSi is ...

Abstract Silica separation and isolation methods providing energy conservation, a decrease in losses and waste of plant raw materials, and the environmental safety of the processes are studied. Using the oxidative ashing and alkaline extraction methods, biogenic silica (SiO2) samples with a target component content of …

First published: 29 December 2016. https://doi/10.1002/l0435. Citations: 10. Sections. PDF. Tools. Share. Abstract. The burial efficiency of biogenic silica (BSi) in deltaic sediments is associated both with the …

Another approach to estimate F W is to consider the benthic efflux from sediments devoid of biogenic silica deposits. Frings (2017) estimates that "non-biogenic-silica" sediments (i.e., clays and calcareous sediments, which cover about 78 % of the ocean area) may contribute up to 44.9 Tmol Si yr −1 via a benthic diffusive Si flux.

Dissolved silica (DSi) is a key nutrient for the aquatic ecosystem as diatoms have an essential requirement for DSi to build up their frustules, rigid outer cell walls made of amorphous biogenic silica (BSi) (Ragueneau et al. 2000).Diatoms often dominate the primary production in turbid aquatic environments such as rivers, estuaries and coastal …

Some of the most common siliceous structures observed at the cell surface of silica-secreting organisms include: spicules, scales, solid plates, granules, frustules, and other elaborate geometric forms, depending on the species considered. Silicate, or silicic acid (H4SiO4), is an important nutrient in the ocean. Unlike the other major nutrients such as …

The solubility of biogenic silica is greater in warm surface waters than in colder deep waters, which, coupled with the increasing silicate concentration with depth in most …

Abstract. Oxygen isotopes in biogenic silica (δ18OBSi) from lake sediments allow for quantitative reconstruction of past hydroclimate and proxy-model comparison in terrestrial environments. The signals of individual records have been attributed to different factors, such as air temperature (Tair), atmospheric circulation patterns, hydrological …

Biogenic silica may undergo other transformations during late diagenesis, producing more stable forms of silica such as chert. During late diagenesis, processes such as compaction and cementation are also involved in conversion of biogenic calcite and aragonite into limestone and dolomite (see Holland and Turekian 2014 and chapters …

Although the biogenic pool of Si in soils is known to be of central importance to plant uptake and Si cycling in natural forest and grassland ecosystems, its role in agricultural systems is controversial and unclear. The biogenic pool is mainly composed of phytogenic (plant-derived) amorphous silica (deposited in plant shoots as phytoliths) but ...

Measurements of natural cosmogenic 32 Si (t 1/2 ~ 140 years) in tropical deltaic sediments demonstrate for the first time that most 32 Si is present in rapidly formed authigenic clays and not biogenic opaline silica (bSi). The burial of bSi in deltaic and continental margin sediments has likely been greatly underestimated because of …

Biogenic silica showed to be non-cytotoxic on skin keratinocytes, at concentrations up to 5 wt%, and non-skin sensitizer. A positive effect on the stimulation of pro-collagen I alpha 1 suggests a potential anti-ageing activity, while the migration of fibroblasts to a wounded area suggests a regenerative capacity. Under an accelerated stability ...

Diatoms and biogenic silica (biogenic Si) in sediments are commonly analyzed as paleoceanographic environmental indicators. However, the correspondence between these sedimentary components and their counterparts in the water column above can vary over time and space. This study, undertaken in the northern South China Sea, …

29 Sep 2021. North Atlantic marine biogenic silica accumulation through the early to middle Paleogene: implications for ocean circulation and …

Oceanography, Chemical. James H. Mathewson, in Encyclopedia of Physical Science and Technology (Third Edition), 2003 III.E Biogenous Sedimentation. Ocean sediments consist of biogenic silica (global average of 14%), calcite (48%), and aluminosilicate dust …

Biogenic silica (BSi), a chemically determined proxy, measures the amorphous Si content. of sediments. It has been shown to be a good proxy for diatom abundance (Conley, 1988) and for other ...

Aluminum (Al) is taken up by living diatoms to be incorporated into the structure of diatom-derived biogenic silica (DBSi) (biogenic Al) and adsorbed by DBSi of post-mortem diatoms (adsorbed Al). Al can inhibit the dissolution of DBSi and thus influence carbon sequestration. However, the mechanism of Al occurrence in DBSi remains unclear.

Two bio-inorganic polymers, biogenic polyphosphate (bio-polyP) and biogenic silica (bio-silica), which have been considered as promising biomimetic bone substitution materials, are formed in plants, animals and some bacterial taxa and both gained interest in the recent few years [8,9]. These biologically formed polymers, …

Land use change affects biogenic silica pool distribution in a subtropical soil toposequence. Abstract. Land use change (deforestation) has several negative consequences for the soil system. It is known to increase erosion rates, which affect the distribution of elements in soils. In this context, the crucial nutrient Si has received little ...