biogenic silica investigation

biogenic silica investigation

Limnological investigation of biogenic silica

Schelske, C.L., Züllig, H. & Boucherle, M. Limnological investigation of biogenic silica sedimentation and silica biogeochemistry in Lake St. Moritz and Lake Zürich. Schweiz. Z. Hydrol 49, 42–50 (1987). https://doi/10.1007/BF02540378. Download citation. Received: 11 August 1986. Issue Date: February 1987. DOI: https://doi/10.1007/BF02540378

Synthesis of biogenic silica nanoparticles from rice

2015-1-1  In this investigation, we synthesized biogenic silica nanoparticles (bSNPs) using rice husk as a precursor. Under pressurized conditions, the rice husk was acid pretreated to remove inorganic impurities and induce the hydrolysis of organic substances.

(PDF) Biogenic Silica ResearchGate

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,

Biogenic Silica SpringerLink

The measurement of the biogenic silica (BSi) content of sediments is a chemical estimate of the siliceous microfossil abundance. Briefly, sediments are leached with a weak base, usually Na 2 CO 3, for a period of time (2–5 hours), and aliquots withdrawn over time. The aliquots are then measured for the amount of Si extracted and a least-squares regression is made on the increase in concentration with time to

Minerals Free Full-Text Evidence for Biogenic Silica

Although previous studies have proved the existence of biogenic silica in shales by excluding terrigenous detrital silica and hydrothermal silica, few studies have investigated how to exclude authigenic silica formed during clay mineral transformation.

(PDF) Biogenic Silica researchgate.net

Biogenic Silica (BSi) has been one of the most important proxies for determining the palaeoclimate from Lake Baikal over glacial-interglacial cycles.

Highly Hierarchical Fibrillar Biogenic Silica with

2020-8-5  A new discovery of highly hierarchical fibrillar biogenic silica with mesoporous structure derived from the perennial plant Equisetum fluviatile was made. By removing the organic compounds through chemical and heat treatment, the biogenic silica skeleton can largely retained the original highly hierarchical structure of the plant stems. Infrared spectra, X-ray diffraction, and small-angle X

Modeling responses of diatom productivity and

2007-8-17  The modeled depth-time distribution of sinking biogenic silica (BSi) indicates that it would take more than 30 days after iron injection to detect any significant BSi export out of the euphotic zone. Sensitivity studies were performed to establish the importance of fertilized patch size, duration of fertilization, and the role of mesozooplankton grazing.

Ternary biogenic silica/magnetite/graphene oxide

Biogenic silica (SiO 2) has been used to fabricate composites for various applications, for instance, enzyme immobilization [1,2]. Moreover, mostly amorphous biogenic SiO 2 is more reactive over sol-gel or pyrogenic SiO 2,plus its minute pore size can easily accommodate a wide range of proteins and improve enzyme loading capacity [4,5].

(PDF) Biogenic Silica ResearchGate

the measurement of biogenic silica (BSi) in sediments. Three basic modifications of this. technique are commonly used: 1) A moderate strength base is used (2 M Na 2 CO 3) and the. sample is

Forsmark site investigation Analyses of biogenic silicon

Analyses of biogenic silicon in sediments in Lake Eckarfjärden AP PF 400-07-008 1.0 Method description Ohlendorf C, Sturm M. PM-BSi: A modified method for biogenic silica

(PDF) Biogenic Silica researchgate.net

The measurement of the biogenic silica (BSi) content of sediments is a chemical estimate of the siliceous microfossil abundance. Briefly, sediments are leached with a weak base, usually Na2CO3

Biogenic silica cycle in surface sediments of the

2000-1-1  Biogenic silica contents of surface sediments from the Greenland Sea are shown in Fig. 2.Generally, very low BSi contents of <2 wt.% were observed. These BSi contents are close to the detection limit of leaching and other techniques applied for the determination of absolute BSi content (Schlüter and Rickert, 1998).Nevertheless, due to the high accuracy of the extraction technique,

Minerals Free Full-Text Evidence for Biogenic Silica

Silicas in shale include terrigenous detrital silica, biogenic silica, hydrothermal silica, and authigenic silica formed during clay mineral transformation [8,9,10,11]. Terrigenous detrital silica is a weathering product of terrestrial parent rocks and can be moved to marine environments by mechanical transportation .

Synthesis of biogenic silica nanoparticles from rice

2015-1-1  However, biogenic silica is an excellent alternative to synthetic silica because of its variable structure, density, and composition. Among the available agricultural bioresources, rice husk is considered to be a cost-effective and non-metallic bio-precursor for biogenic silica nanoparticle synthesis.

OF BIOGENIC SILICA ACCUMULATION IN THE LOW

OF BIOGENIC SILICA ACCUMULATION IN THE LOW-LATITUDE ATLANTIC 1 Naja Mikkelsen2 and John A. Barron3 ABSTRACT Pronounced biogenic silica accumulation has taken place in the Ceara Rise region during two episodes of the Cenozoic: the early Oligocene (33.5−30.5 Ma) and the early Miocene (23.0−15.5 Ma). The Paleogene deposits are dominated by

Determination of biogenic silica in coastal waters

The NaOH/HF digestion method, used for the determination of particulate biogenic silica (BSi) and of particulate lithogenic silica (LSi) in oceanic waters, has been applied to coastal waters. In the course of one year, 275 samples of suspended matter were collected at two stations located in the Bay of Brest and in the English Channel (Western

Dissolution kinetics of biogenic silica in marine

column and surface sediments are important aspects for the investigation and reconstruction of present and past productivities of the ocean because biogenic silica is intimately linked to the carbon cycle. Because the controls On biogenic silica dissolution

Modeling responses of diatom productivity and

2007-8-17  [1] Using a three-dimensional physical-biogeochemical model, we have investigated the modeled responses of diatom productivity and biogenic silica export to iron enrichment in the equatorial Pacific, and compared the model simulation with in situ (IronEx II) iron fertilization results. In the eastern equatorial Pacific, an area of 540,000 km 2 was enhanced with iron by changing the

Forsmark site investigation Analyses of biogenic silicon

Analyses of biogenic silicon in sediments in Lake Eckarfjärden AP PF 400-07-008 1.0 Method description Ohlendorf C, Sturm M. PM-BSi: A modified method for biogenic silica

Highly Hierarchical Fibrillar Biogenic Silica with

2020-7-21  Scanning electron microscopy and transmission electron microscopy investigation reveal that the biogenic silica are fibers with diameters of about 120-150 μm and lengths of

Distribution and accumulation of biogenic silica in the

analysis of biogenic silica and its diagenetic derivatives, the two-step mild acid-mild alkaline extraction procedure was used to leach biogenic silica in sediments, which is evaluated to be more e cient in dissolving sedimentary biogenic silica and its altered products (Michalopoulos and Aller, 2004). In brief, triplicate about 50–70 mg sediment

The influence of biogenic silica on seismic

Quantification of Biogenic Silica During routine shipboard analysis of smear slides, biogenic silica content is estimated. Smear-slide estimates of biogenic silica content are difficult, however, and often inaccurate (overestimate) due to the large area covered by diatoms compared to their weight. For this study, we use

Dissolution kinetics of biogenic silica in marine

The production and dissolution processes of biogenic silica (BSi) in the water column and surface sediments are important aspects for the investigation and reconstruction of present and past productivities of the ocean because biogenic silica is intimately linked to the carbon cycle.

Sensitivity of biogenic silica oxygen isotopes to

2005-4-9  In summary, the true value of the temperature coefficient for biogenic silica oxygen isotopes is still controversial. [6] In this contribution we report results of the first calibration study dedicated to the investigation of the temperature‐dependent oxygen isotope fractionation between diatom silica and water directly in an ecosystem. Our approach avoids problems of former studies and, therefore, should

Export and dissolution of biogenic silica in the Yellow

2018-3-20  Biogenic silica (BSi) is an important source of dissolved silica (DSi) in aquatic ecosystems and thus plays an important role in the Earth's Si cycle (Conley, 2002; Laruelle et al., 2009; Tréguer and De La Rocha, 2013; Song et al., 2014, 2016). The cycling of BSi in the ocean has been studied extensively due to the importance of diatoms in the primary production.

Biogenic silica: a neglected component of the coupled

2008-7-25  Important ‘silica bioengineers’ in freshwater ecosystems comprise diatoms, sponges and chrysophytes. This paper reviews the biological role of Si in higher plants, the impact of vegetation on rates of chemical weathering, the fluxes of Si through

Modeling responses of diatom productivity and

2007-8-17  The modeled depth-time distribution of sinking biogenic silica (BSi) indicates that it would take more than 30 days after iron injection to detect any significant BSi export out of the euphotic zone. Sensitivity studies were performed to establish the importance of fertilized patch size, duration of fertilization, and the role of mesozooplankton grazing.

Biogenic Material an overview ScienceDirect Topics

Biogenic silica as precipitated by diatoms, radiolaria, sponges, and silicoflagellates is in the form of opal-A, which is highly disordered and almost completely amorphous. As mentioned earlier the X-ray diffraction pattern for biogenic silica yields only a very broad peak at ~20–26° two theta.