Rice Hull Ash Research Articles

Fabrication and characterization of strontium incorporated 3-D bioactive glass scaffolds for bone tissue from biosilica

Bioactive glass scaffolds that contain silica are high viable biomaterials as bone supporters for bone tissue engineering due to their bioactive behaviour in simulated body fluid (SBF). In the human body, these materials help inorganic bone structure formation due to a combination of the particular ratio of elements such as silicon (Si), calcium (Ca), sodium (Na) and phosphorus (P), and the doping of strontium (Sr) into the scaffold structure increases their bioactive behaviour. In this study, bioactive glass scaffolds were produced by using rice hull ash (RHA) silica and commercial silica based bioactive glasses. The structural properties of scaffolds such as pore size, porosity and also the bioactive behaviour were investigated. The results showed that undoped and Sr-doped RHA silica-based bioactive glass scaffolds have better bioactivity than that of commercial silica based bioactive glass scaffolds. Moreover, undoped and Sr-doped RHA silica-based bioactive glass scaffolds will be able to be used instead of undoped and Sr-doped commercial silica based bioactive glass scaffolds for bone regeneration applications. Scaffolds that are produced from undoped or Sr-doped RHA silica have high potential to form new bone for bone defects in tissue engineering.

Effects of Pre- and Postharvest Treatments of Silicon and Rice Hull Ash on Vase Life of Gerbera

This study was conducted to investigate the effects of different silicon supplements and postharvest treatments on growth and yield of gerbera in a greenhouse experiment. Silicon supplements were including potassium silicate at three concentrations (0, 140 and 200 mg L−1), sodium silicate at three concentrations (0, 50 and 100 mg L−1) and rice hull ash (RHA) at three concentrations (0, 50 and 100 mg L−1). Also, postharvest treatments were including sucrose, salicylic acid (200 and 400 mg L−1), methyl jasmonate (15 and 25 mg L−1) and distilled water (as control). The application of potassium silicate, RHA and sodium silicate led to decrease in dry weight of flower. Shoot length and diameter were substantially higher in 140 mg L−1 potassium silicate than those in control treatment. The maximum inflorescence diameter was observed in rice husk ash (50 mg L−1). Capitulum diameter was far greater in sodium silicate at 50 mg L−1 compared to other treatments. Vase life of gerbera flower was greater in 400 mg L−1 salicylic acid and 15 mg L−1 methyl jasmonate than in control treatment. The maximum inflorescence diameter was observed in 400 mg L−1 salicylic acid. This study confirmed that the studied sources of Si, salicylic acid and methyl jasmonate increased marketable quality of cut gerbera flowers.

Mechanical and Thermal Properties of Geopolymers from Mixtures of Coal Ash and Rice Hull Ash using Water Glass Solution as Activator

Geopolymers, from industrial wastes such as blast furnace slag, red mud, and coal ash, among others, have emerged as technically viable, economically competitive, and environmentally attractive supplements and even alternatives to ordinary Portland cement (OPC). Furthermore, while the most impact shall be achieved with large-scale use in the general building and structural sector, as replacement or supplement to OPC, the properties of these geopolymers may be optimized for special niche applications. One of these applications is for light weight, low thermal conductivity, heat resistant, and moderate strength cement binder for low rise residential buildings. In this study, compressive strength, heat resistance, volumetric weight, mass loss, water absorption and thermal conductivity of geopolymers formed from mixtures of coal bottom ash and rice hull ash (CBA-RHA) and coal fly ash and rice hull ash (CFA-RHA) with sodium silicate solution (modulus 2.5) as activator were evaluated. Using mixture design and the JMP statistical software, the CBA-RHA combination at a mass ratio of 46% CBA, 32% RHA with 22% WGS gave properties at maximum desirability of 17.6 MPa compressive strength, 1640 kg/m3 volumetric weight, 273 kg/m3 water absorption, 28 MPa compressive strength after high temperature exposure (1000oC for 2 hours) with 4.4% mass loss, and 0.578 W/m-K thermal conductivity. On a performance basis, even as the geopolymers are formed as paste, these properties fall within the standards for lightweight OPC based-concrete with strength requirements for residential buildings. The low thermal conductivity and higher strength after high temperature exposure vis-à-vis OPC are additional advantages for consideration.

Anthracite briquettes with plant byproducts as an ecofriendly fuel for foundries

Anthracite briquettes were developed using mainly waste anthracite fines, plant byproducts of rice hulls and rice hull ash and silicon metal powder as an ecofriendly fuel and as an alternative to conventional coke used in a cupola furnace. Si metal powder reacts with anthracite to form SiC, which provides high mechanical strength to an anthracite briquette when it is exposed to a high temperature in the cupola furnace. Rice hull and rice hull ash, which are agricultural byproducts with high SiO2 content were investigated as partial substitutes for silicon as the former are inexpensive relative to silicon metal. The formation of SiC was investigated under different conditions using X-ray diffraction and transmission electron microscopy. In addition, unconfined compressive strength of the briquettes was measured when the rice hull or ash substituted Si powder partially or completely. When anthracite briquettes prepared with elemental Si powder and either rice hull ash or rice hull powder were pyrolyzed at 1400°C for 2h, SiC formed and the briquettes showed high mechanical strength in the range of 2000–4000kPa, which is enough to keep their structural integrity in a cupola furnace.

The Study of Organic Fertilizers Application on Two Soybean Varieties in Organic Saturated Soil Culture

Indonesia is facing soybean shortage and the low productivity of soybean production from decreasing acreage. Saturated soil culture (SSC) could be one of the solutions for marginal land with drainage problem. Saturated soil culture is cultivation technology that gives continuous irrigation and maintains water depth constantly and makes soil layer in saturated condition. Farmers can use on-farm inputs that are normally available at the production site. An organic farming system may be able to ensure local and regional food security through continuous production. The study was conducted at Cikarawang Experimental Station of Bogor Agricultural University, Indonesia, from December 2009 to February 2011. The objective of the research was to determine the influence of organic fertilizer application on the productivity of two varieties of soybean, “Anjasmoro” and “Wilis”, in organic saturated soil culture conducted in two cropping seasons. Prior to the experiment all plots were applied with 2 ton.ha-1 of dolomite, 2 ton.ha-1 of rice hull ash, and 10 ton.ha-1 of chicken manure. The experiment of the first season used split plot design with six replications. The main-plot was organic fertilizer that consisted of chicken manure only (20 ton.ha-1), chicken manure (10 t.ha-1) + Centrosema pubescens (4.2 t.ha-1), chicken manure (10 ton.ha-1) + Tithonia diversifolia (4.2 t.ha-1). The sub-plot was soybean varieties “Anjasmoro” and “Wilis”. The soybean productivity was not affected by the application of organic fertilizers. “Willis” productivity (1.98 t.ha-1) was higher than “Anjasmoro” (1.80 t.ha-1). The experiment of second season used split-split plot design with three replications. The main-plot consisted of 50 and 100% fertilizer rate of the first cropping season; the sub-plot was the same types of organic fertilizer with soybean varieties as sub-sub-plot. Rate of fertilizer, types of organic fertilizer and soybean variety did not affect productivity. Application of 50 and 100% rate of fertilizer in the second season produced 2.41 and 2.55 t.ha-1 of dry seeds, respectively. Soybean plants treated with chicken manure, green manure from C. pubescens and T. diversifolia produced 2.45, 2.50 and 2.49 t.ha-1 of dry seeds, respectively. “Anjasmoro” and “Wilis” produced 2.50 and 2.45 t.ha-1 of dry seeds, respectively. Productivity in the second season was 26.26-36.61% higher than those of the first cropping season.

Escaping the Tyranny of Carbothermal Reduction: Fumed Silica from Sustainable, Green Sources without First Having to Make SiCl4.

Fumed silica is produced in 1000 tons per year quantities by combusting SiCl4 in H2 /O2 flames. Given that both SiCl4 and combustion byproduct HCl are corrosive, toxic and polluting, this route to fumed silica requires extensive safeguards that may be obviated if an alternate route were found. Silica, including rice hull ash (RHA) can be directly depolymerized using hindered diols to generate distillable spirocyclic alkoxysilanes or Si(OEt)4 . We report here the use of liquid-feed flame spray pyrolysis (LF-FSP) to combust the aforementioned precursors to produce fumed silica very similar to SiCl4 -derived products. The resulting powders are amorphous, necked, <50 nm average particle sizes, with specific surface areas (SSAs) of 140-230 m(2) g(-1) . The LF-FSP approach does not require the containment constraints of the SiCl4 process and given that the RHA silica source is produced in million ton per year quantities worldwide, the reported approach represents a sustainable, green and potentially lower-cost alternative.

Influence of Textural Properties and Surface Fractal Dimensions on the Cobalt Adsorption Behavior of Rice Hull Ash Prepared via Solid Combustion

Rice hull ash was prepared via a fast chemical combustion method with ammonium nitrate, urea and milled rice hull. Urea was used as the chemical fuel. The mixture was heated to various temperatures (100 to 1000 °C), and the resulting products were compared with products obtained via calcination, in which samples were heated to the same temperatures for 2 hours. Changes in the structure, morphology, texture and surface fractal dimensions with respect to temperature were examined and found to be highly relevant for adsorption applications. The prepared powders were characterized physicochemically by X-ray diffraction and N2-physisorption measurements. The surface fractal dimensions of the prepared materials were calculated from N2-adsorptiondesorption isotherms. The results indicate that the fast combustion samples have larger surface fractal dimensions than calcined samples. A correlation between fractal dimensions and Co 2+ ion adsorption was found. The present study demonstrates the importance of textural properties and surface fractal dimensions in the adsorption performance of adsorbents.

Avoiding Carbothermal Reduction: Distillation of Alkoxysilanes from Biogenic, Green, and Sustainable Sources

AbstractThe direct depolymerization of SiO2 to distillable alkoxysilanes has been explored repeatedly without success for 85 years as an alternative to carbothermal reduction (1900 °C) to Simet, followed by treatment with ROH. We report herein the base‐catalyzed depolymerization of SiO2 with diols to form distillable spirocyclic alkoxysilanes and Si(OEt)4. Thus, 2‐methyl‐2,4‐pentanediol, 2,2,4‐trimethyl‐1,3‐pentanediol, or ethylene glycol (EGH2) react with silica sources, such as rice hull ash, in the presence of NaOH (10 %) to form H2O and distillable spirocyclic alkoxysilanes [bis(2‐methyl‐2,4‐pentanediolato) silicate, bis(2,2,4‐trimethyl‐1,3‐pentanediolato) silicate or Si(eg)2 polymer with 5–98 % conversion, as governed by surface area/crystallinity. Si(eg)2 or bis(2‐methyl‐2,4‐pentanediolato) silicate reacted with EtOH and catalytic acid to give Si(OEt)4 in 60 % yield, thus providing inexpensive routes to high‐purity precipitated or fumed silica and compounds with single Si−C bonds.

Avoiding Carbothermal Reduction: Distillation of Alkoxysilanes from Biogenic, Green, and Sustainable Sources.

The direct depolymerization of SiO2 to distillable alkoxysilanes has been explored repeatedly without success for 85 years as an alternative to carbothermal reduction (1900 °C) to Si(met) , followed by treatment with ROH. We report herein the base-catalyzed depolymerization of SiO2 with diols to form distillable spirocyclic alkoxysilanes and Si(OEt)4. Thus, 2-methyl-2,4-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, or ethylene glycol (EGH2) react with silica sources, such as rice hull ash, in the presence of NaOH (10%) to form H2O and distillable spirocyclic alkoxysilanes [bis(2-methyl-2,4-pentanediolato) silicate, bis(2,2,4-trimethyl-1,3-pentanediolato) silicate or Si(eg)2 polymer with 5-98% conversion, as governed by surface area/crystallinity. Si(eg)2 or bis(2-methyl-2,4-pentanediolato) silicate reacted with EtOH and catalytic acid to give Si(OEt)4 in 60% yield, thus providing inexpensive routes to high-purity precipitated or fumed silica and compounds with single Si-C bonds.

Guano and Rice-Hull Ash Application for Flowering Induction on Orange Jessamine (Murraya paniculata (L.) Jack)

Orange jessamine (Murraya paniculata (L.) Jack) has high economical values due to its medicinal properties. Orange jessamine leaves contain flavonoid, mexotionin and coumarin. Orange jessamine flowers contain scopoletin that can lower blood pressure and can be used as an anti-inflammatory agent and as anti-allergic. Orange jessamine is often used as an ornamental plant because it has beautiful flowers similar to jasmine, has nice scent, and red color fruits. The aim of this research is to study the effects of guano and rice-hull ash application on flowering induction of orange jessamine. The research was conducted at an organic experimental farm, Bogor Agricultural University, Darmaga (6°30' – 6°45' S, 106°30'-106°45' E) from December 2014 to June 2015 using randomized complete block design. The experiment used four treatments, i.e. guano at 0.4 kg per plant, combination of guano (0.4 kg per plant) and rice-hull ash (3.0 kg per plant), rice-hull ash 3.0 kg per plant and without fertilisation as control. The results showed that the application of rice-hull ash increased plant height and leaf number. Guano application significantly increased the intensity of leaf color in mature orange jessamine leaves. Rice-hull ash application increased flower number at 12 and 20 weeks after application.Keywords: chlorophyll, flower number, flower weight, NPK value, organic farming

Chitosan Membrane with Blending of Rice Hull Ash Silica and Polyethylene Glycol for Cu(II) Adsorption in Aqueous Solution

In this research, polyethylene glycol (PEG) and rice hull ash silica were blended to modify chitosan membrane to improve the adsorption capability of copper ion. Scanning electron microscopy (SEM) and water affinity were performed to characterize membranes. Batch adsorption experiments were conducted with various contact time and Cu (II) concentrations to evaluate the adsorption kinetics and thermodynamics. Results show that adsorption fitted to Langmuir model and followed a kinetic model of pseudo-second-order.

A novel solid phosphoric acid from rice hull ash for olefinic alkylation of thiophenic sulfur in gasoline

ABSTRACT A novel solid phosphoric acid (SPA) was prepared from rice hull ash by impregnation with phosphoric acid and followed by calcination. The characterization results reveal that the solid phosphoric acid exhibits high surface area (335 m 2 /g) and acid densities (1.25 mmol/g) compared with commercial SPA catalyst. It was also clearly confirmed that silicon phosphate and silicon pyrophosphate were formed by the reaction of silica with phosphoric acid during the calcination process. The OATS catalytic performance results indicate that the solid phosphoric acid shows very good activity for thiophene alkylation reaction. This research provided a promising way to synthesis high active solid phosphoric acid for OATS desulfurization application.

Production, Characterization and Bioactivity of 46S6 Bioactive Glass from Rice Hull Ash Silica

In the present study, 46S6 bioactive glasses with composition 46 SiO2% –24% Na2O – 24% CaO – 6% P2O5in weight percent were synthesized through melt-derived process using alkali extracted silica from rice hull ash and commercial silica. Bioactive glasses were incubated in SBF (simulated body fluid), before and after immersing in SBF, characterized by SEM to investigate degradation and apatite formation. Also bioactivity tests such as cell culture, cell viability and cytotoxicity, differentiation, mineralization and alkaline phosphatase assay have been performed. Results showed that 46S6 bioactive glasses from rice hull ash silica had better metabolic activity and viability than that obtained from commercial silica.

Effect of Organic Fertilizer-Based Azolla, Rock Phosphate and Hull Ash on Rice Yield and Chemical Properties of Alfisols

Effect of Azolla Based - Organic Fertilizer, Rock Phosphate and Rice Hull Ash on Rice Yield and Chemical Properties of Alfisols . The application of chemical fertilizer for long time may adverse soil environment. Organic agriculture, for example combination use of azolla based-organic fertilizer, phosphate rock and rice hull ash, was one of ways that able to recover it. Research was conducted in Sukosari, Jumantono, Karanganyar while soi chemical properties analysis was analysed in Soil Chemistry and Fertility Laboratory, Fac. of Agriculture, Sebelas Maret University April to November 2013. Research design used was RAKL with 5 treatments, each repeated 5 times. The treatments applied were P0 (control), P1 ( azola inoculum dosage 250 g/m 2 + phosphate rock + rice hull ash equal to 150 kg/ha KCl), P2 (azola inoculum dosage 500 g/m 2 + phosphate rock equal to 150kg/ha, SP-36 + rice hull ash equal to 100 kg/ha KCl), P3 (manure dosage of 5 ton/ha),P4 (Urea 250 kg/ha + SP-36 150 kg/ha + KCl 100 kg/ha). Data analysed statistically by F test (Fisher test) with level of confident 95% followed by DMRT (Duncan Multiple Range Test) if any significant differences. The result showed that the treatment combination of azolla, phosphate rock and rice hull ash increase soil organic matter content, cation exchange capacity, available-P and exchangeable-K as well as rice yield ( (at harvest-dry grain weight and milled-dry grain weight).

The Effect of Azolla Inoculum, Phosphate Rock and Rice Hulk Ash Dosages on Rice Yield and Soil Physical of Alfisols

TITLE : THE EFFECT OF AZOLLA INOCULUM, PHOSPHATE ROCK AND RICE HULL ASH DOSAGES ON RICE YIELD AND SOIL PHYSICAL OF ALFISOLS. The use of agrochemical materials to increase rice yield in a long term may cause soil, environment damages and have low productivity. One of the ways to increase the rice yield and improve soil health is organic rice cultivation by applaying organic fertilizer inputs derived from azolla. This research objective is to find out the effect of azolla, phosphate rock and husk ash dosages, as well as the best combination of azolla, rock phosphate and husk ash which is best for soil physical and yield of rice on Alfisols. The experimental design used was Completely Randomized Design (CRD), consists of 5 treatment and repeated 5 times. Data analysis using the F test (Fisher test) with 95% level confidence. Variables measured were field capacity, maximum moisture content, bulk density, aggregate stability, plant height, dry weight of harvest rice and milled rice. The results showed the treatment combination of azolla 250 g m -2 , rock phosphate equivalent with 150 kgha -1 SP-36 and husk ash equivalent with 100 kgha -1 KCl give the highest aggregate stability.

Improving the Nutrient Quality of Carrot and Fruit Juice Wastes Mixture for Poultry Diet Through Utilization of Rice-Hull Ash Filtrate

Improving the Nutrient Quality of Carrot and Fruit Juice Wastes Mixture for Poultry Diet Through Utilization of Rice-Hull Ash Filtrate

A low cost, low energy route to solar grade silicon from rice hull ash (RHA), a sustainable source

Polycrystalline silicon, with impurity levels lower than those of the SEMI III standard for solar grade silicon feedstock (≈99.9999% pure), was produced using rice hull ash (RHA) as a biogenic silica source.

Coating of magnetite with mercapto modified rice hull ash silica in a one-pot process.

In this research, mercapto-silica coated magnetite (Fe3O4-SiO2-SH) has been prepared in aqueous solution through a simple approach so called a one-pot process. The Fe3O4-SiO2-SH was prepared in nitrogen condition by mixing magnetite, 3-mercaptopropyltrimethoxysilane (MPTMS), and sodium silicate (Na2SiO3) solution extracted from rice hull ash, and adjusting the pH of 7.0 using hydrochloric acid. The residue was washed with deionized water, dried at 150°C and separated with an external magnetic field. In that work, the volume of MPTMS and Na2SiO3 was varied and the total amount of Si represented as silica was kept constant. Characters of the material including the functional group presence, the structure, the porosity, the morphology and stability toward various solvents were identified and evaluated. Results of characterization indicated that mercapto-silica has been coated magnetite particle with a simple one-pot process. Coating mercapto-silica on magnetite increases particle size, surface area, and chemical stability. Additionally, Fe3O4-SiO2-SH also shows high stability toward various organic solvents. The magnetic property of magnetite does not change after coating and the addition of nonmagnetic material still gives high value of maximum saturation magnetization. The presence of mercapto groups effective for interaction with heavy metal ions, the high chemical stability without removing the magnetic property promises the prospective application of Fe3O4-SiO2-SH in the future such as for separation and removal of heavy metal ions from aquatic environments.

Comparative study of soybean oil refining using rice hull silicate and commercial adsorbents

To obtain an edible grade of soybean oil, impurity removal processes are important steps in refining. To remove coloring compounds and free fatty acids, commercial adsorbents (silica gel, activated carbon, aluminum oxide, alumina silicate, acid clay, and zeolite) and rice hull silicate (RHS) were evaluated with respect to their adsorption removal efficiencies for lutein. Various doses of commercial adsorbents and RHS were individually added to degummed soybean oil to remove lutein. The commercial adsorbents and RHS substantially reduced lutein amounts in degummed soybean oil. Silica gel was the most effective adsorbent, followed by acid clay, and RHS. Treatments with adsorbents also reduced the residual free fatty acid (FFA) content. Aluminum oxide was the most effective in removal of FFA (approximately 40% reduction). RHS and rice hull ash (RHA) showed similar deacidification effects. RHS can be used as an alternative bleaching agent as it was effective in reducing the residual FFA content in soybean oil.

Prospects of Use and Impact of Nanoparticles on the Properties of High-Strength Concrete

The basic properties of concrete can dramatically improve due to the unique structure of the nanosized particles. Namely, strength, frost resistance, fire resistance, corrosion resistance are increased, density and permeability are reduced; plasticity and water absorption are regulated. Despite of the huge number of advantages of nanomodified concrete, analysis of the use of nanoparticles shows that they are used quite seldom, as it requires a large cash outlay. It is not always profitable to use such additives. This article discusses some additives: magnesium nanoshpinel, microspheres, rice hull ash and metakaolin, astralenes, ferric hydroxide sol, carbon nanotubes, silica fume, nanosilica, MB-01, combined modifiers, based on iron hydroxide sol and silica sol. As well in this article sol-gel method as an additive in concrete is considered. The analysis shows that the use of nanosized particles can reduce a large amount of cement. As an addition, savings of the use are seen in reducing the cost of construction due to the low density with high strength. Accurate material consumption and maximum use of advantages of nanomodified concrete provide great prospects of implementation of this material in construction.