Silicic Acid Research Articles

Relative abundance of silicolytic bacteria in different habitats and its statistical analysis

Silicolytic bacteria are widely distributed playing significant role in silicon cycle. They convert silica into free silicic acid which is taken up by various life forms. Silicases catalyze dissolution of silica into silicic acid. Herein, diversity of silicolytic bacteria in different types of soil samples and wild grasses was studied by plate assay using different media. Silicase activity of two isolates from two different habitats was compared. The results revealed that silicolytic bacteria were abundant in number but their population varied in different habitats. Paddy field soil and wild grasses harbored the highest population of silicolytic bacteria. Different screening media were evaluated. Pigment and exo-polysachharide were also produced by some silicolytic endophytes. Statistical analysis showed that silicolytic bacterial population in paddy soil and wild grasses was significantly abundant as compared to that in dumping land and contaminated soil around heavy metal industries.

A Comprehensive Review on the Potential Effect of Silicon Fertilizer and its Significance for Agriculture

Silicon (Si) is one of the most prevalent elements in the Plant’s crust which is mostly made up of silicates. Si is not regarded as needed for plant growth and development; nonetheless, there is growing evidence in the literature that this metalloid is advantageous to plants, particularly when plants are under stress. Silicon (Si) is notoriously difficult to eradicate from the nutritional substrate of plants, it has been impossible to demonstrate that plants cannot finish their life cycles without Silicon. Nevertheless, plants get advantages from the presence of Silicon, and it has been shown that Si may boost the plant's resistance to both biotic and abiotic challenges, providing the plant with protection and stability. By analyzing the data that is currently accessible in the published research, this investigation will explore the positive impact of silicon on plant growth. Si transporters are responsible for mediating the movement of Silicon, which is taken up in silicic acid. The amorphous SiO2 structures known as phytolites are generated inside the plant. The decomposition of plants results in the return of phytolites to the soil, which in turn results in the return of Silicon to the soil, where subsequent generations of plants can take it up. Many other kinds of proteins work in concert with Si to protect plants from various pathogens. These data indicate that Silicon must be classified as a necessary plant nutrient rather than just a helpful one. In this study, we highlight the function of Silicon in the soil as well as in plants, particularly with a focus on micronutrients, metabolites, Si fertilizer, crop quality, Prophylactic effects from crop diseases, phytolites, and their importance, the role of Silicon in plant roots, the role of Silicon in plant protection, stabilization, and enhancing plant health and performances, and the role of Silicon in phytolites.

The GRAS Salts of Na2SiO3 and EDTA-Na2 Control Citrus Postharvest Pathogens by Disrupting the Cell Membrane.

Sodium silicate (Na2SiO3) and ethylenediaminetetraacetic acid disodium salt (EDTA-Na2) are inorganic salts classified as 'Generally Recognized as Safe' (GRAS) compounds with great advantages in controlling various pathogens of postharvest fruits and vegetables. Here, we determined the median effective concentration (EC50) of Na2SiO3 (0.06%, 0.05%, 0.07% and 0.08%) and EDTA-Na2 (0.11%, 0.08%, 0.5%, and 0.07%) against common pathogens affecting postharvest citrus fruit, including Penicillium digitatum, Penicillium italicum, Geotrichum citri-aurantii, and Colletotrichum gloeosporioides. Na2SiO3 and EDTA-Na2 treatments at the EC50 decreased the spore germination rate, visibly disrupted the spore cell membrane integrity, and significantly increased the lipid droplets (LDs) of the four postharvest pathogens. Moreover, both treatments at EC50 significantly reduced the disease incidence of P. italicum (by 60% and 93.335, respectively) and G. citri-aurantii (by 50% and 76.67%, respectively) relative to the control. Furthermore, Na2SiO3 and EDTA-Na2 treatment resulted in dramatically lower disease severity of the four pathogens, while also demonstrating no significant change in citrus fruit quality compared with the control. Therefore, Na2SiO3 and EDTA-Na2 present a promising approach to control the postharvest diseases of citrus fruit.

An efficient silica scale inhibiting strategy for geothermal systems: Combination of cationic and anionic polymers

AbstractCationic silica scale inhibitors are widely used, but are prone to precipitation and exhibit poor performance in geothermal systems. In this study, the cationic polymer polyethyleneimine ethoxylate (PEIE) was first found to have high silica scale inhibition efficiency. Three anionic polymers were added separately to PEIE solutions to alleviate the precipitation and scaling. The inhibition effect of PEIE alone and PEIE with anionic polymers were measured at 40°C without salt and 136.7°C with salt. Molecular dynamics simulation was used to investigate the inhibition mechanism. The results showed that PEIE exhibited good inhibition efficiency of 62% at 40°C without salt and 48% at 136.7°C with salt, while the addition of the anionic polymer acrylic acid‐2‐acrylamide‐2‐methylpropanesulfonic acid (AA/AMPS) to PEIE further improved to 71% and 62%. Compared with commercial inhibitors, the PEIE + AA/AMPS enhanced at least 15% scale inhibition efficiency. This is because the addition of AA/AMPS: (1) enhances the attraction of PEIE to silicic acid and inhibits the silicic acid condensation process; (2) chelates metal ions that promote condensation; and (3) enhances dispersion ability, stabilizing the colloid formed by PEIE and silicic acid. This study provides a promising new inhibitor and efficient strategy for inhibiting silica scale in geothermal systems.

Rapid Determination of PCDDs, PCDFs and DL-PCBs in Foods, Feedingstuffs and Vegetable Oils Using New Modified Acid Silica

Rapid Determination of PCDDs, PCDFs and DL-PCBs in Foods, Feedingstuffs and Vegetable Oils Using New Modified Acid Silica

Folic acid and carbon dots-capped mesoporous silica for pH-responsive targeted drug delivery and bioimaging

Folic acid and carbon dots-capped mesoporous silica for pH-responsive targeted drug delivery and bioimaging

Silicon and growth regulator induced defence against maize fall armyworm, Spodoptera frugiperda (J.E. Smith)

A microplot field experiment was conducted to study the effect of silicon sources and growth regulator against maize fall armyworm, Spodoptera frugiperda at Thoppur village of Virudhunagar district during Rabi, 2021-22. Basal application of different doses of calcium silicate and foliar application of silicic acid and potassium silicate were carried out. The results revealed that 150 kg of calcium silicate/ha + 0.2% silicic acid at 15 d after sowing (DAS) + 50 ppm GA at 30 DAS was found to be effective in reducing fall armyworm (FAW) population (1.23 larvae/plant) followed by treatment with 75 kg of calcium silicate/ha + 0.2% silicic acid at 15 DAS + 50 ppm GA at 30 DAS (1.27 larvae/plant). Regarding leaf and cob damage, the treatment with 150 kg of calcium silicate/ha + 0.2% silicic acid at 15 DAS + 50 ppm GA at 30 DAS was found to be most effective and significantly superior over all other treatments by recording lowest mean leaf damage score of 1.63/plant and mean cob damage score of 1.13/plant followed by the treatment with 75 kg of calcium silicate/ha + 0.2% silicic acid at 15 DAS + 50 ppm GA at 30 DAS with 1.66 leaf score/plant and 1.35 cob score/plant.

Inhibition of Surface Corrosion Behavior of Zinc-Iron Alloy by Silicate Passivation

The passivation of zinc alloy coating was achieved through the utilization of both silicate and trivalent chromium passivation systems, employing a specific process formula consisting of Co(NO3)2 at a concentration of 2.5 g/L, C76H52O46 at 3 mL/L, Na2SiO3 at 25 g/L, C6H5Na3O7 at 15 g/L, and an appropriate amount of organic accelerator. The composite passivation of silicate and tannic acid was found to be more effective than the trivalent chromium passivation film, as it successfully eliminated the dendrite structure on the coating surface and reduced surface defects. The coordination between negatively charged SiO2− or SiO2 micelles and Zn2+ results in the formation of a passivation film that exhibits lower corrosion current and higher corrosion potential compared to the trivalent chromium passivation film. Additionally, the impedance test fitting results indicate that the silicate passivation film possesses a higher resistance value. Overall, the proposed silicate passivation system presents a viable alternative to the toxic chromate passivation system, offering non-toxicity and superior protective performance relative to the trivalent chromium passivation system.

The use of potassium silicate and fulvic acid to mitigate the effects of heat stress in tomato plants

The use of potassium silicate and fulvic acid to mitigate the effects of heat stress in tomato plants

Implementing propagating low- temperature synthesis to produce pure silicon carbide

The results of research into the formation of ultrapure silicon carbide by propagating synthesis are described in the paper. This synthesis provides a reduction of process time and energy costs. It is established that the main structural transition is caused by phase transformations and polymorphism phenomenon in silica (α-SiO 2 to β-SiO 2 transition) which is necessary to produce pure silicon carbide. It is determined that in a given time interval under the influence of imposed conditions and subsequent interaction with silicic acid and active carbon begins spontaneous transition with the formation of ultrapure silicon carbide. The implementation of the proposed technology increases the silicon carbide yield to 95‒99 % with a nanoscale product (40‒60 nm) of 99,99 % purity

Morphology of Oil Palm (Elaeis guineensis Jacq.) Seedlings Under Drought Stress with Oil Palm Shell Ash and Aspergillus niger treatment

Climate change is a limiting factor that contributes to weather anomalies such as varying rainfall intensity. Weather abnormalities impact plantation crops, such as oil palm, which are very sensitive to water deficits, and inhibition of growth in the nursery phase reduces seed quality. In an effort to increase the resistance of oil palm seedlings to drought stress, palm shell ash is given because it contains high silicon (Si) ranging from 43% to 63%. Furthermore, the fungus Aspergillus niger is known to decompose and release insoluble silicon into orthosilicic acid into the soil solution, which can be absorbed by plants, This study used randomized block design with two factors drought stress factor with four level field capacity (FC) of 80%, 60%, 40% dan 20%; factor palm oil shell and Aspergillus niger 0, 10, 20, 30 g + 5 ml/polybag. The results showed that the parameter number of Aspergillus niger colonies before and after the drought stress treatment decreased, drought stress was also a significant difference in the parameters of plant height and number of leaves, while the treatment of oil palm shell ash with the addition of Aspergillus niger had no significant effect on plant height parameters and number of leaves of oil palm seedlings.

Experimental study on new grouting material of acidic sodium silicate and its properties of grouted-sand

Slurry selection and ratio optimization are the key points and difficulties in the construction of subway tunnels in poorly graded medium sand strata. In this paper, a kind of acidic grouting material was prepared by using sodium silicate and phosphoric acid. The properties of the acidic grouting material including gel time and viscosity were studied. Orthogonal test was carried out to optimize the ratio of sodium silicate to phosphoric acid for poorly graded sand stratum. At the same time, X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to analyze the sand consolidation process of the slurry. The results show that the gel time and funnel viscosity of the phosphoric acid-sodium silicate slurry are related to the Baume degree of sodium silicate and the volume ratio of sodium silicate to phosphoric acid. The compressive strength of the grouted sand is related to four factors, i.e., water content of the sand, and Baume degree, pH value and curing time of the slurry, the influence degree of which is in the following order: D (curing time) > A (water content) > B (Baume degree of sodium silicate) > C (pH value of the slurry). The final slurry selected for grouting reinforcement of the weakly alkaline medium sand strata was prepared by 30 °Bé sodium silicate with 14 % phosphoric acid at a volume ratio of 0.5. It has a gel time of 51.48 min, a funnel viscosity of 16.43 s and a pH value of 3.47. The increased amount of silica gel in the sample is the main reason for the increased strength of the grouted sand. The amount of silica gel generated increases with the increase of the curing time of the sample.

Determination of polybrominated diphenyl ethers in marine sediments by composite chromatography column purification-gas chromatography-negative chemical ionization-mass spectrometry

Polybrominated diphenyl ethers (PBDEs) are used as additive flame retardants. Because they lack the ability to form chemical bonds, PBDEs can easily enter the sediment environment. The accurate qualitative and quantitative analysis of PBDEs in sediments is of great importance for the accurate assessment of PBDE pollution in this environment. Sediments contain many impurities. Therefore, PBDEs in sediment should be purified before analysis to reduce the matrix effect. A method based on gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI/MS) was developed to determine 13 PBDEs in marine sediment samples using a column packed with deactivated silica gel, acidified silica gel, Florisil, and anhydrous sodium sulfate. Sediment samples were extracted by ultrasonication with a mixed solvent of n-hexane-dichloromethane (3∶1, v/v). After two cycles of ultrasonic extraction, the extract was purified by a composite chromatographic column and eluted with n-hexane-dichloromethane (3∶1, v/v). Thirteen PBDEs were determined by GC-NCI/MS in selected-ion monitoring (SIM) mode. The effects of different fillers, eluents, and elution volumes on the purification of PBDEs in the composite column were compared and analyzed, and the GC-NCI/MS analysis conditions were optimized. Three different packing columns were used to purify the sample extract. The first column was packed with 3 g of deactivated silica, 6 g of acidic silica, 3 g of deactivated silica, 3 g of Florisil, and 6 g of anhydrous sodium sulfate; the second column was packed with 3 g of Florisil, 3 g of deactivated silica, 6 g of acidic silica, 3 g of deactivated silica, and 6 g of anhydrous sodium sulfate; and the third column was packed with 3 g of deactivated silica, 6 g of acidified silica, 3 g of deactivated silica, and 6 g of anhydrous sodium sulfate. Among these columns, that packed with 3 g of deactivated silica, 6 g of acidic silica, 3 g of deactivated silica, 3 g of Florisil, and 6 g of anhydrous sodium sulfate showed the best purification effect. The 13 PBDEs showed good linearity in the mass concentration range of 0.1-20 μg/L with correlation coefficients (r2) greater than 0.995 (decabromodiphenyl oxide (BDE-209), r2>0.99). The limits of quantification (S/N=10) was 0.002-0.126 μg/kg. The average recoveries of the 13 PBDEs at three spiked levels of 0.2, 1.0, and 4.0 μg/kg were 85.3%-101.3%, 84.8%-113.6%, and 86.3%-94.7% with relative standard deviations of 4.4%-14.0%, 0.4%-4.9%, and 1.9%-6.6%, respectively. These findings indicate that the method has high sensitivity and accuracy as well as good precision. Finally, the method was applied to the analysis and detection of PBDEs in actual marine sediment samples. The results revealed that the sediment samples contained different contents of the 13 PBDEs, and high detection rates were obtained for lower-brominated PBDE homologs. The detection rate of bis(4-bromophenyl) ether (BDE-15) was 100%, and the detected content of BDE-209 was as high as 60.49 μg/kg. These results demonstrate that the developed method is suitable for the accurate qualitative and quantitative analysis of PBDEs in marine sediment samples.

From promoting aggregation to enhancing obstruction: A negative feedback regulatory mechanism of alleviation of trivalent chromium toxicity by silicon in rice

Trivalent chromium [Cr(III)] is a threat to the environment and crop production. Silicon (Si) has been shown to be effective in mitigating Cr(III) toxicity in rice. However, the mechanisms by which Si reduces Cr(III) uptake in rice are unclear. Herein, we hypothesized that the ability of Si to obstruct Cr(III) diffusion via apoplastic bypass is related to silicic acid polymerization, which may be affected by Cr(III) in rice roots. To test this hypothesis, we employed hydroponics experiments on rice (Oryza sativa L.) and utilized apoplastic bypass tracer techniques, as well as model simulations, to investigate 1) the effect of Si on Cr(III) toxicity and its obstruction capacity via apoplastic bypass, 2) the effect of Cr(III) on silicic acid polymerization, and 3) the relationship between the degree of silicic acid polymerization and its Cr(III) obstruction capacity. We found that Si reversed the damage caused by Cr(III) stress in rice. Si exerted an obstruction effect in the apoplast, significantly decreasing the share of Cr(III) uptake via the apoplastic bypass from 18% to 11%. Moreover, Cr(III) reduced silica particles' radii and increased Si concentration in roots. Modeling revealed that a 5-fold reduction in their radii decreased the diffusion of Cr(III) in apoplast by approximately 17%. We revealed that Cr(III) promoted silicic acid polymerization, resulting in the formation of a higher number of Si particles with a smaller radius in roots, which in turn increased the ability of Si to obstruct Cr(III) diffusion. This negative feedback regulatory mechanism is novel and crucially important for maintaining homeostasis in rice, unveiling the unique role of Si under Cr(III) ion stress and providing a theoretical basis for promoting the use of Si fertilizer in the field.

Study on ultrasonic depolymerization of Si-Ge precipitation in zinc oxide dust leaching process

Under the background of the increasing demand for germanium in high-tech, this paper finds out the mechanism of silicon germanium polymerization precipitation by simulating the leaching process of zinc oxide dust containing germanium. By comparing and analyzing the simulation experiments under ultrasonic and conventional conditions, the mechanism of efficient dispersion and depolymerization of germanium silicon precipitation induced by ultrasonic was found out. The results show that in the leaching process of germanium-containing zinc oxide dust, due to the increase of local pH, some silicon ions in the solution will hydrolyze and polymerize to form silicic acid colloid to adsorb germanium in the solution, causing the loss of germanium 14.81%, resulting in low recovery rate of germanium industry. Ultrasonic wave was introduced in the leaching process, and the shock wave and micro-jet released by ultrasonic cavitation continuously impacted the surface of polysilicate colloid. The germanium adsorbed on the surface of the silicic acid colloid is desorbed, and the large particles of silica gel are depolymerized into small particles of silicic acid, which reduces the adsorption of silica gel on germanium. The loss of germanium under ultrasonic conditions can be reduced by 59.35%. This study can effectively realize the efficient recovery of germanium in zinc oxide dust, and provide process and theoretical basis for the sustainable development of germanium industry.

Pro-Osteogenic and Anti-Inflammatory Synergistic Effect of Orthosilicic Acid, Vitamin K2, Curcumin, Polydatin and Quercetin Combination in Young and Senescent Bone Marrow-Derived Mesenchymal Stromal Cells.

During aging, bone marrow mesenchymal stromal cells (MSCs)-the precursors of osteoblasts-undergo cellular senescence, losing their osteogenic potential and acquiring a pro-inflammatory secretory phenotype. These dysfunctions cause bone loss and lead to osteoporosis. Prevention and intervention at an early stage of bone loss are important, and naturally active compounds could represent a valid help in addition to diet. Here, we tested the hypothesis that the combination of two pro-osteogenic factors, namely orthosilicic acid (OA) and vitamin K2 (VK2), and three other anti-inflammatory compounds, namely curcumin (CUR), polydatin (PD) and quercetin (QCT)-that mirror the nutraceutical BlastiMin Complex® (Mivell, Italy)-would be effective in promoting MSC osteogenesis, even of replicative senescent cells (sMSCs), and inhibiting their pro-inflammatory phenotype in vitro. Results showed that when used at non-cytotoxic doses, (i) the association of OA and VK2 promoted MSC differentiation into osteoblasts, even when cultured without other pro-differentiating factors; and (ii) CUR, PD and QCT exerted an anti-inflammatory effect on sMSCs, and also synergized with OA and VK2 in promoting the expression of the pivotal osteogenic marker ALP in these cells. Overall, these data suggest a potential role of using a combination of all of these natural compounds as a supplement to prevent or control the progression of age-related osteoporosis.

Chrome-Free Tanning: Effect of a Combination Tannage Based on Mimosa and Biogenic Silica from Rice Husk

Chromium (III) sulfate is a popular tanning agent for producing leather. However, chrome tanning wastewater is one of the problems in the leather tanning industry. To prevent this, tanning using vegetable materials can be used in the leather tanning process. One of the natural ingredients that can be used is mimosa. However, mimosa is relatively expensive, so a substitute/combination tanning agent is needed to make tanning costs cheaper. This research aims to determine the effect of using a combination of mimosa and silicic acid from rice husk (RHSA) tanners on the quality of the tanned leather produced. This research uses a completely randomized factorial design with mimosa and RHSA as factors. The analysis shows that the best treatments were 20% mimosa and 20% RHSA. In addition, the analysis shows that the treatment met the standard. The resulting shrinkage temperature was 84 °C, tear strength was 39.98 N mm-1, tensile strength was 26.42 N mm-2 and elongation at break was 41%. Combination tanning also shows no significant difference from conventional tanning and reduces mimosa without decreasing leather quality.

Chrome-Free Tanning: Effect of a Combination Tannage Based on Mimosa and Biogenic Silica from Rice Husk

Chromium (III) sulfate is a popular tanning agent for producing leather. However, chrome tanning wastewater is one of the problems in the leather tanning industry. To prevent this, tanning using vegetable materials can be used in the leather tanning process. One of the natural ingredients that can be used is mimosa. However, mimosa is relatively expensive, so a substitute/combination tanning agent is needed to make tanning costs cheaper. This research aims to determine the effect of using a combination of mimosa and silicic acid from rice husk (RHSA) tanners on the quality of the tanned leather produced. This research uses a completely randomized factorial design with mimosa and RHSA as factors. The analysis shows that the best treatments were 20% mimosa and 20% RHSA. In addition, the analysis shows that the treatment met the standard. The resulting shrinkage temperature was 84 °C, tear strength was 39.98 N mm-1, tensile strength was 26.42 N mm-2 and elongation at break was 41%. Combination tanning also shows no significant difference from conventional tanning and reduces mimosa without decreasing leather quality.

ROLE OF ENVIRONMENTAL SILICA IN BIOLOGICAL AND MICROBIAL STRESS MANAGEMENT FOR CROP PRODUCTION

The most prevalent mineral in the earth's mantle is silicon, which ranks second only to oxygen, but unlike oxygen, it has not been shown to be necessary for plant development. Plants can only absorb silicon in one of two forms: silicic acid (Si (OH) 4) or mono silicic acid (H4 SiO4), neither of which is found in the planet's crust as silicon dioxide (SiO2). Silicon fertilizer has been shown toboost agricultural output and sustainability, and its use has been met with widespread praise. When water is lost via the stomata of a plant, the gel that has been polymerized from the silicon solution in the roots is precipitated out of solution. It has been shown that polymerized gel has no significant part in the physical functions of the plant system. This article reviews the function that silicon in soil, water, and plants plays in protecting ecosystems against abiotic and biotic pressures. The interplay between silicon, plant species, and environments is nuanced.

Ascorbic Acid and Calcium Silicate Improve MorphoPhysiological Characteristics of Cadmium Stressed Mung Bean Crop

A rise in heavy metal contamination especially in the rhizosphere affecting the growth and yield of crops is a major concern. We aimed to study the influence of using calcium silicate (CS) and ascorbic acid (AsA) supplements on lowering the impact of cadmium-induced toxicityin mung bean. Both the supplements alone or in combination improved growth characteristics of cadmium (Cd) stressed mung bean plants like root-shoot length and fresh-dry weight. Leaf pigments like chlorophyll and carotenoids were also restored. A significant improvement in the relative leaf water content (RLWC) and low electrolyte leakage (EL) at the membrane was recorded. Results were more promising when combinations of CS and AsA treatments were used against the lower concentration of cadmium. Hence, both CS and AsA interact synergistically to alleviate Cd induced metal toxicity in mung bean plants.