Rice Husk Silica Research Articles

High Performance Concretes with Highly Reactive Rice Husk Ash and Silica Fume.

The search for new sources of high-quality non-crystalline silica as a construction material for high-performance concrete has attracted the interest of researchers for several decades. Numerous investigations have shown that highly reactive silica can be produced from rice husk, an agricultural waste that is abundantly available in the world. Among others, the production of rice husk ash (RHA) by chemical washing with hydrochloric acid prior to the controlled combustion process has been reported to provide higher reactivity because such a process removes alkali metal impurities from RHA and provides an amorphous structure with higher surface area. This paper presents an experimental work in which a highly reactive rice husk ash (TRHA) is prepared and evaluated as a replacement for Portland cement in high-performance concretes. The performance of RHA and TRHA was compared with that of conventional silica fume (SF). Experimental results showed that the increase in compressive strength of concrete with TRHA was clearly observed at all ages, generally higher than 20% of the strength obtained with the control concrete. The increase in flexural strength was even more significant, showing that concrete with RHA, TRHA and SF increased by 20%, 46%, and 36%, respectively. Some synergistic effect was observed when polyethylene-polypropylene fiber was used for concrete with TRHA and SF. The chloride ion penetration results also indicated that the use of TRHA had similar performance compared to that of SF. Based on the results of statistical analysis, the performance of TRHA is found to be identical to that of SF. The use of TRHA should be further promoted considering the economic and environmental impact that will be achieved by utilizing agricultural waste.

POZZOLAN EFFECT ON THE MECHANICAL PROPERTIES OF SCBA BLENDED CEMENT TREATED SOIL

The recent agricultural and industrial waste reduction research has focused on monetary, sustainable environment, and technological considerations. Discarded raw materials such as rice husk ash, fly ash, coir fiber and silica fumes were widely explored and successfully utilized as blending elements for cement. Current studies have proved that Sugarcane Bagasse Ash (SCBA) produced from sugar production has a pozzolanic reaction due to the high substance of amorphous silica in this raw material. This research would boost the insight of potential blending agents that can reduce the cost and stabilize problematic soil. This study intends to evaluate the effect of SCBA blended cement on improved soil’s mechanical properties, including the shear strength and the compressibility of the treated soil. Unconfined Compressive Strength test was conducted to attain the compressive behavior, while the One-Dimensional test was performed to examine the compressibility behavior. The tested samples with SCBA show a beneficial effect in terms of both compressive strength and compressibility. This study proved that SCBA could be applied at least as a partial substitute to the Portland cement.

EPOXY RESIN, VINYL COPOLYMER, AND RICE HUSK SILICA BASED TERNARY NANOCOMPOSITES: FABRICATION, MECHANICAL CHARACTERISTICS, AND THERMAL AGING

In this research, the bio-composites based on epoxy resin filled with nano-silica and vinyl copolymer were fabricated using diethylene triamine as a curing agent and casting method. The vinyl copolymer was synthesized from Hydroxyethyl Acrylate and Methacrylic acid using ammonium persulfate as an initiator. The bio-silica was extracted from rice husk via a simple technique of acid treatment and calcination. The chemical structure of poly(HEA-Co-MAA), silica was confirmed with help of the FTIR, and NMR-1H. The high-speed mechanical stirrer was used to obtain the good dispersion of silica and poly(HEA-Co-MAA) in epoxy resin before mixing and curing with Diethylenetriamine (DETA) hardener. The thermal stability of cured epoxy resin was enhanced with the presence of rice husk silica and poly(HEA-Co-MAA). The composite sample with 1 wt.% of bio-silica and 3 wt.% of poly(HEA-Co-MAA) showed the best mechanical properties with an improvement of up to 28.82%; and 35.36% of impact strength and tensile strength, respectively when compared with a pristine sample. The aging testing was also performed to investigate the effect of additive added on the thermal resistance of epoxy resin.

Exploration on ability of printable modified papers for the application in heat sublimation transfer printing of polyester fabric

In this work heat transfer papers were loaded with a new core–shell pigment based on precipitating thin shell of titanium dioxide on a core of rice husk silica ash TiO2/RHSA to be applied in dye sublimation printing of textile fabrics. Besides, 0.1% (w/w) cationic polyacrylamide (CPAM) and 1% (w/w) bentonite (Bt) were also added sequentially to improve drainage and filler retention of the paper hand-sheets made from bleached kraft bagasse pulps. The effect of the new core–shell pigment on the mechanical and barrier properties, thermal stability and surface morphology of modified paper sheets were investigated. In addition, the study of transfer printability and ease of dye release from paper to fabric in this heat transfer printing of polyester fabrics using silk-screen printing under different transfer parameters were studied. Also, fastness measurements including washing, light and perspiration of printing polyester fabric were also estimated.

Evaluation of concrete with CBD: A comprehensive review

In most of the countries the main consumer of energy and materials is considered to be the construction industry. To ensure future generation sustainability, numerous research works focused on the use of sustainable and renewable were done. At present, the energy crisis and global warming are major concerns and there is an urgent need to reduce the usage of cement because of the higher carbon dioxide footprint of the cement industry. This challenge can be addressed by partial replacement of cement with different pozzolanic materials like fly ash, ground granulated blast furnace slag (GGBS), rice husk ash, dolomite, silica fume, and Clay Brick Dust (CBD). CBD is recycled waste material that is obtained from the demolishing of fired clay brick construction and from other usages requiring the fired bricks. The construction and demolition process produces a million tonnes of solid waste globally, and clay brick waste shares the major part of it. The pozzolanic properties of CBD give a significant role in the strength and durability of concrete. CBD does have more silicon and aluminium oxides, which promote the pozzolanic process. The usage of CBD in concrete will address the high cost and scarcity of cement. It also helps to balance the demand for construction due to the rise in population and the sustainability of the environment across the world. According to studies, using CBD in place of cement in concrete produces a variety of outcomes with variable CBD replacement percentages and fineness. Adding a suitable quantity of CBD to cementitious materials can improve their mechanical characteristics. However, if the amount of CBD in a cementitious material is too high, the mechanical characteristics of the material will deteriorate. According to available studies, the optimal percentage of CBD replacement in cement is between 10 and 15%. Hence, based on the ongoing research, this study summarizes the mechanical, and durability properties of the partially replaced cement concrete with CBD.

Effects of Fiber Loading on Mechanical Properties of Kenaf Nanocellulose Reinforced Nanohybrid Dental Composite Made of Rice Husk Silica

The innovation of nanocellulose as reinforcement filler in composites has been a topic of interest in the development of new biomaterials. The objective of this study was to investigate the mechanical properties of a nanohybrid dental composite made of rice husk silica and loaded with different percentages of kenaf nanocellulose. Kenaf cellulose nanocrystals (CNC) were isolated and characterized using a transmission electron microscope (TEM) (Libra 120, Carl Zeiss, Germany). The experimental composite was fabricated with fiber loadings of 1 wt%, 2 wt%, 3 wt%, 4 wt%, and 6 wt% silane-treated kenaf CNC, and subjected to a flexural and compressive strength test (n = 7) using an Instron Universal Testing Machine (Shimadzu, Kyoto, Japan), followed by a scanning electron microscopic assessment of the flexural specimen's fracture surface using a scanning electron microscope (SEM) (FEI Quanta FEG 450, Hillsborough, OR, USA). Commercial composites Filtek Z350XT (3M ESPE, St. Paul, MN, USA), Neofil (Kerr Corporation, Orange, CA, USA) and Ever-X Posterior (GC Corporation, Tokyo, Japan) were used as a comparison. The average diameter of kenaf CNC under TEM was 6 nm. For flexural and compressive strength tests, one-way ANOVA showed a statistically significant difference (p < 0.05) between all groups. Compared to the control group (0 wt%), the incorporation of kenaf CNC (1 wt%) into rice husk silica nanohybrid dental composite showed a slight improvement in mechanical properties and modes of reinforcement, which was reflected in SEM images of the fracture surface. The optimum dental composite reinforcement made of rice husk was 1 wt% kenaf CNC. Excessive fiber loading results in a decline in mechanical properties. CNC derived from natural sources may be a viable alternative as a reinforcement co-filler at low concentrations.

Study on the Reaction Parameters on Transesterification of Rubber Seed Oil Using MgO/zeolite-A Catalyst

In this research, transesterification of rubber seed oil (RSO) with methanol in the presence of MgO/zeolite-A composites with different MgO loads as catalysts was investigated. In addition, the effect of different reaction parameters including oil to methanol ratio, the amount of catalyst, and transesterification time were also investigated. Zeolite-A was prepared from rice husk silica (RHS) and food-grade aluminum foil and confirmed using XRD and SEM/EDS techniques. The MgO/zeolite-A composites with different MgO loads were prepared by impregnating the zeolite with Mg (NO3)2 solution of different concentrations. The composites were then characterized using XRF, XRD, and SEM, and finally applied as a catalyst in transesterification of RSO at varied experimental conditions. The XRF results indicated that the zeolite has been successfully impregnated, and the content of MgO varied depending on the concentration of magnesium nitrate solution used for impregnation process. Zeolite-A and also MgO/zeolite-A composites were confirmed by XRD investigations, supported by SEM analysis with indicated the shape of cubic particle, a characteristic feature of zeolite-A, and rod like structure which is most likely the MgO particle. The results of transesterification experiments revealed the appreciable activities of the composites and the effect of reaction parameters on the conversion of the RSO, with the highest conversion of 89 % achieved using 12.5 % catalyst relative to the mass of RSO, with MgO 4.43 %/zeolite-A catalyst, oil to methanol ratio of 1:10, and a transesterification time of 6.0 h. Analysis of the transesterification products using GC-MS confirmed that fatty acids composing the RSO were converted into corresponding methyl esters. HIGHLIGHTS Zeolite A was prepared from rice husk silica and food grade aluminum foil MgO/Zeolite A composites with different MgO load were prepared using impregnation method MgO/Zeolite A composites were used as catalyst for transesterification of rubber seed oil GRAPHICAL ABSTRACT

Improvements in the mechanical behavior of a silty soil treated with rice husk silica, lime, and polypropylene fiber

ABSTRACT Stabilized soils correspond to a change in their properties to improve mechanical and engineering performance. This research aims to improve a silty soil from Guabirotuba Formation with 5% lime and three different rice husk silica contents (5%, 10%, 15%) and reinforce these same mixtures with the 0.5% polypropylene fibre. Geotechnical and chemical characterization, unconfined compressive strength (UCS), and the split tensile strength (STS) tests were performed in four different cure times (0, 30, 60, and 90 days). The results showed that the stabilized samples UCS and STS tests at 90 days of cure presented a resistance nine times bigger than the pure soil and the polypropylene fibre made the samples become more ductile. Finally, by simulating a pavement design applying these improved mixtures on the subgrade layer, a thickness reduction on the base layer was observed, going from 444.5 mm with pure soil to 203.2 when the mixtures were applied.

CHARACTERISATION OF HIGH PURITY RICE HUSK SILICA SYNTHESISED USING SOLVENT-THERMAL TREATMENT WITH DIFFERENT CONCENTRATION OF ACID LEACHING

In recent years, research on bio-based materials, such as rice husk is steadily gaining momentum. Despite their huge developmental potential, rice husks are often left unutilised following the harvesting season, wasting a natural wealth that could be explored. Their high silica content makes them potential fillers to replace commercial precipitated silica in the polymer industry, composites and building materials for construction. In this study, highly pure silica with small particle size and high surface area was extracted from rice husks via solvent-thermal treatment, followed by leaching with different concentrations of hydrochloric acid (HCl). This treatment method was modified from TAPPI T204 (2007) and TAPPI T264 (1997) standards, which are used for wood extraction in the pulp and papermaking industry. By using this method, rice husk silica (RHS) that was leached with 1.0 M HCl recorded the highest particle purity with 99.99% of SiO2 content and the highest BET surface area of 234.25 m2/g compared with RHS leached with 0.01 M, 0.1 M, 2.0 M, and 3.0 M HCl. All RHS samples were in the amorphous state following incineration at 700°C for 4 hours. This proved that RHS synthesised by solvent-thermal treatment method can be further developed as one of the alternatives to commercial silica in the market.

SINTESIS DAN KARAKTERISASI WOLLASTONITE BERBASIS PREKUSOR BIOGENIK SILIKA ABU SEKAM PADI

The aim of this research is to make wollastonite from silica obtained from rice husk ash and commercial calcium carbonate using the solids reaction method. The DTA-TGA results show mass due to the evaporation of H2O and the decomposition of CaCO3 into CaO along with the calcination temperature, in addition, the DTA results also identify the formation of the β-CaSiO3 phase and the α-CaSiO3 phase. The XRD results of wollastonite obtained were dominated by the β-CaSiO3 phase and the minor phase was α-CaSiO3 this was indicated by the peak intensity of the β-CaSiO3 phase which was higher than the peak intensity of the α-CaSiO3 phase. the second phase in wollastonite is also the result of FTIR results through the analysis of the Si-O-Ca functional group in each wollastonite sample. In addition, the results of the SEM analysis showed the shape of the spheroidal particles (spherical) with an average grain size of 0.19 m, 0.35 m and 0.68 m for the calcination temperatures of 900 oC, 1000 oC and 1100 oC, respectively. The results of this study indicate that the manufacture of wollastonite from the basic ingredients of rice husk silica and commercial calcium carbonate has potential as an alternative material for the manufacture of wollastonite.

Effect of the addition of silica obtained from rice husk on physicochemical and mechanical properties of fibercement

After replacing asbestos with other types of fibers used as reinforcement of cementitious matrices, it has been found that rice husk, an agro-industrial waste with high silica content, can be used to improve the properties of fibercement. In this work, the effect of adding different forms of silica (rice husk, rice husk ash, and silica microparticles) on fibercement's physicochemical and mechanical properties was investigated. Rice husk ash and silica microparticles were extracted from the rice husk incineration and acid leaching process. The chemical composition of silica was determined by X-Ray Fluorescence, and the ash leached with hydrochloric acid was found to contain more than 98% silica. Cement, fiberglass, additives, and different forms of silica were used to manufacture fibercement specimens in their different forms. Concentrations of 0%, 3%, 5%, and 7% were taken for each form of silica, and four replicates were performed. The setting time was 28 days, during which absorption, density, and humidity tests were performed. Experiments were statistically analyzed at a 95% confidence value, and it was determined that there are significant differences in the compressive resistance, density, and absorption in relation to the type of additive and the interaction between the type of additive and its percentage of addition, but not whit percentage of addition. It was found that the fibercement specimens with 3% of rice husk present a modulus of elasticity of 9.4% higher than de control sample. The use of rice husk as an additive in fibercement composites seems to be interesting because these agro-industrial wastes are inexpensive and easily available everywhere to utilize in the cement industry and also helpful in reducing environmental pollution due to their cost and the positive effect on their properties.

Enhanced Carbon Storage Process from Flue Gas Streams Using Rice Husk Silica Nanoparticles: An Approach in Shallow Coal Bed Methane Reservoirs

Carbon capture and storage (CCS) is considered a key process to reach net-zero emission by the 2050 aim of limiting global warming. Coal bed methane (CBM) is considered potential geological reservoirs for underground CCS due to the CO2–CH4 exchange feasibility by adsorptive phenomena. Global implementation has been focused only on deep reservoirs to provide methane recovery. Thus, this work proposes a modified CCS process based on silica nanoparticle inclusion for shallow CBM reservoirs (<300 m). The nanomaterials were evaluated at high pressure in two main stages including i) CO2 sorption on a single CO2 stream and ii) CO2 selectivity on a flue gas stream (N2–CO2 mixture). This work includes silica nanomaterial synthesized from rice husk as agro-waste sources with better technical-economic feasibility framed in a circular economy to reduce costs and maximize the use of available resources. Rice husk silica (RSi) nanoparticles were doped with 1.0, 3.0, and 5.0 wt % of urea (Si–U), diethylamine (Si-DE), triethylamine (Si-TE), and ethylenediamine (Si-EM) to enhance the CO2 sorption. First, CO2 sorption was evaluated at 30 °C and between 0.084 and 3 MPa using a CO2 stream to determine the best-doped amount of each N-source. Then, the best nanoparticles were used to impregnate CBM at 10 and 20 wt %, and the subsequent CO2 storage on the flue gas stream (70% v/v N2 and 30% v/v CO2) was done. The results showed that CO2 sorption on RSi increases with the N-group coating in the order RSi-DE < RSi-TE < RSi-U < RSi-EM. Also, the best-doped amount for each N-source was 3 wt %. For CBM impregnation, the nanofluid containing 20 wt % of RSi-EM3 presented the best yield increasing the CO2 sorption from 0.05 to 0.75 mmol g–1, meaning an increase of more than 1000% in the sorption capacity.

Enabling stable cycling performance with rice husk silica positive additive in lead-acid battery

Lead-acid battery has been widely used in stationary energy storages, such as photovoltaic application, grid service and uninterrupted power system due to the advantages of high safety, recyclability, and low cost. However, the low cyclic performance limits its further applications in emerging functions. One of the main failure modes is caused by the high polarization on the PbO2 positive plate. Herein, the rice husk silica with hierarchical porous structure was used as the positive additive for preventing from the high polarization of the PbO2 positive plate. Nitrogen adsorption-desorption isothermal and X-ray diffraction confirmed that the hierarchical porous rice husk silica enlarged the electrochemical surface area of the PbO2 positive plate, endowing a high rate of active material utilization and low polarization during the charging process. Compared with the blank plate, the PbO2 plate with rice husk silica showed improved Coulombic efficiency and a prolonged cycle life. These notable features verify that the porous rice husk silica is a cost-effective positive additive for sustained lead-acid batteries.

Alternative Fillers in Asphalt Concrete Mixtures: Laboratory Investigation and Machine Learning Modeling towards Mechanical Performance Prediction.

In recent years, due to the reduction in available natural resources, the attention of many researchers has been focused on the reuse of recycled materials and industrial waste in common engineering applications. This paper discusses the feasibility of using seven different materials as alternative fillers instead of ordinary Portland cement (OPC) in road pavement base layers: namely rice husk ash (RHA), brick dust (BD), marble dust (MD), stone dust (SD), fly ash (FA), limestone dust (LD), and silica fume (SF). To exclusively evaluate the effect that selected fillers had on the mechanical performance of asphalt mixtures, we carried out Marshall, indirect tensile strength, moisture susceptibility, and Cantabro abrasion loss tests on specimens in which only the filler type and its percentage varied while keeping constant all the remaining design parameters. Experimental findings showed that all mixtures, except those prepared with 4% RHA or MD, met the requirements of Indian standards with respect to air voids, Marshall stability and quotient. LD and SF mixtures provided slightly better mechanical strength and durability than OPC ones, proving they can be successfully recycled as filler in asphalt mixtures. Furthermore, a Machine Learning methodology based on laboratory results was developed. A decision tree Categorical Boosting approach allowed the main mechanical properties of the investigated mixtures to be predicted on the basis of the main compositional variables, with a mean Pearson correlation and a mean coefficient of determination equal to 0.9724 and 0.9374, respectively.

A LITERATURE REVIEW ON ALKALI SILICA REACTIVITY OF CONCRETE IN PAKISTAN

Pakistan has variety of topographic features including planes, sub-mountainous andmountainous ranges. These mountainous and sub-mountainous ranges possess a vast potential forconcrete aggregates. However, alkali silica reactivity has largely been observed in the past, due toreactive nature of these aggregates. This study was planned to explore the possible causes of alkalisilica reaction (ASR) and their consequences in the environment of Pakistan. Several materials can beused economically to mitigate alkali silica expansion. Among all possible remedies, use of granulatedblast furnace slag is the most effective and economical option to control ASR. Use of other materialssuch as calcined or bentonite clay, rice husk ash, bagasse ash and silica fume may be effective againstASR.

Enzymatic production of wax esters by esterification using lipase immobilized via physical adsorption on functionalized rice husk silica as biocatalyst.

The present study consists of developing an enzymatic process for the production of wax esters (lauryl stearate and cetyl stearate) by esterification in a heptane medium. Lipase from Thermomyces lanuginosus (TLL) immobilized via interfacial activation on silica particles from rice husks functionalized with triethoxy(octyl)silane (TLL-Octyl-SiO2 ) was used as biocatalyst. Maximum immobilized protein loading of around 22mgg-1 (that corresponds to an immobilization yield of ≈55%) of support was observed using an initial protein loading of 40mgg-1 of Octyl-SiO2 . Its hydrolytic activity (olive oil emulsion hydrolysis) was of 620Ug-1 of biocatalyst. The effect of certain factors on the cetyl estearate production was evaluated using a central composite rotatable design (CCDR). Under optimal conditions (64°C, 21% of mass of biocatalyst per volume of reaction mixture, 170rpm, and stoichiometric acid:alcohol molar ratio 1molL-1 of each reactant), maximum acid conversion percentage of 91% was observed after 60min of reaction. Lauryl stearate was also produced under such conditions, and an acid conversion of 93% after 60min of reaction was also achieved. Free lipase exhibited acid conversion of only 15%-20% for both reaction mixtures. After nine successive esterification batches, TLL-Octyl-SiO2 retained 85%-90% of its original activity. These results show the promising use of the prepared biocatalyst in wax esters production due to its high catalytic activity and reusability.

Valorized rice husk as green corrosion inhibitor for Al 6061 in 1M HCl

This study investigated the inhibition characteristics of rice husk (RH) on corrosion of Aluminum 6061 in 1M hydrochloric acid. Gravimetric analysis and Scanning Electron Microscopy (SEM)/ Energy Dispersive X-ray analysis (EDX) as well as electrochemical studies revealed the potency of RH as a good inhibitor of the corrosion of Al 6061 in 1M HCl. Fourier Transform Infrared Spectroscopy (FTIR) indicated that –OH, C=C, and C=O with signals at (3317.19, 2932.9, 2848.2), (1631.8) and (1105.73, 1030.2, 447.15), respectively in RH were the viable active functional groups which adsorbed on the metal surface to effect reduction of corrosion rates. However, literature suggested the presence of amorphous silica in RH which served as a complimentary corrosion inhibitor. The corrosion current density of Al 6061 was reduced to 3.46 × 10−7 A/cm2 at 24 h as against 9.27 × 10−7 A/cm2 at the commencement of the potentiodynamic polarization measurements in inhibited 1M HCl. The control specimens exhibited an average corrosion rate of 3.86 × 10−6 A/cm2 in HCl solution at the start of this investigation as compared to the corrosion rate of 3.46 × 10−7 A/cm2 at 24 h of exposure in 5 mg RH- inhibited HCl. The obtained results gave a corrosion inhibition efficiency of about 90 to 92%.

Immobilization of heavy metals in tannery sludge by the formation of tobermorite in subcritical water treatment with rice husk silica.

Tannery sludge, heavy metals (HMs) enriched hazardous solid waste, is produced extensively in many regions of the world. Even though the sludge is hazardous, it can be considered a material resource, if organic matter and HMs in the sludge can be stabilized to minimize its negative environmental impacts. This research aimed to evaluate the efficacy of using subcritical water (SCW) treatment for tannery sludge treatment through immobilization and thus reduction of HMs to mitigate their potential environmental risk and toxicity. HMs in the tannery sludge were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) and the average concentration of HMs (mg kg-1) was found in the following decreasing order of Cr (12 950) > Fe (1265) > Cu (76) > Mn (44) > Zn (36) > Pb (14) with very high Cr concentration. The result of toxicity characteristics leaching procedure and sequential extraction procedure tests revealed that the raw tannery sludge leachate contained 11.24 mg L-1 Cr, which classified the raw tannery sludge into a very high-risk category. After SCW treatment, the concentration of Cr in leachate was reduced to 1.6 mg L-1 indicating risk reduction to a low-risk category. The eco-toxicity levels of other HMs also decreased considerably after SCW treatment. X-ray diffractometry (XRD) and scanning electron microscopy (SEM) analysis were employed to identify the effective immobilizing substances formed in the SCW treatment process. The favorable formation of immobilizing orthorhombic tobermorite (Ca5Si6O16(OH)2·4H2O) at 240 °C in the SCW treatment process was confirmed by XRD and SEM analysis. The results confirmed that the formation of 11 Å tobermorite is capable of strongly immobilizing HMs in the SCW treatment process. Further, both orthorhombic 11 Å tobermorite and 9 Å tobermorite were successfully synthesized by SCW treatment on a mixture of tannery sludge including rice husk silica and Ca(OH)2 with water under rather mild conditions. Hence, it can be concluded that SCW treatment of tannery sludge with supplementary silica from rice husk can effectively immobilize the HMs and significantly reduce their environmental risk through tobermorite formation.

BTEXS Removal From Aqueous Phase by MCM-41 Green Synthesis Using Rice Husk Silica

Large volumes of contaminated industrial wastewater have caused growing concern among researchers and environmentalists. Benzene, toluene, ethylbenzene, xylene, and styrene (BTEXS) cyclic hydrocarbons in industrial effluents are often completely stable to biodegradation and must be treated before disposal. In this context, using adsorption processes is a potential alternative for treating a wide range of organic pollutants, especially aromatic compounds in industrial wastewater. This study investigated the preparation of MCM-41 from silica; extracted from rice husk ash; MCM-41 was green synthesized to evaluate the effect of mesoporous used in BTEXS removal of an aqueous medium using the Taguchi method. The aqueous solution contains cyclic hydrocarbons was synthetically prepred based on real industrial effluent in concentrations of 50, 100, and 150 mg/l using MCM-41 catalysts, in doses of 0.1, 0.5, and 1g, at different pH values. In the present study, the optimum results obtained by Taguchi method analysis were pH =11, for duration of 60 minutes, the concentration of cyclic hydrocarbon solution BTEXS 100 mg/l, and nanoparticle dose of 0.5 g. The maximum BTEXS removal of 77.36% was achieved by the use of hydrogen peroxide.

Improvement in Soil Sub Grade Using Rice Husk Ash and Silica Fume by Soil Stabilization.

Abstract: Black cotton soil shows high swelling and shrinkage and less CBR value and strength due to presence of Montmorillonite mineral. Black cotton soil cannot be use for structural purpose in construction industry due to its expensive nature, therefore to control expensive behavior of the soil rise husk ash and silica fume is used in this experimental study. Rise husk ash used 0-15% by weight for observe experiment results and silica fume 0-12% by weight for observation of experiment results. Plasticity index, Free swell index of soil is decreasing with respect to RHA and SF addition and CBR value and shear strength of soil is increasing with respect to addition of RHA and SF . Optimum percentage of rise husk ash (RHA) and Silica fume (SF) observed as 12% and 9% respectively.