Rice Husk Research Articles

Magnetic MgFeO@BC Derived from Rice Husk as Peroxymonosulfate Activator for Sulfamethoxazole Degradation: Performance and Reaction Mechanism.

Heterogeneous Mg-Fe oxide/biochar (MgFeO@BC) nanocomposites were synthesized by a co-precipitation method and used as biochar-based catalysts to activate peroxymonosulfate (PMS) for sulfamethoxazole (SMX) removal. The optimal conditions for SMX degradation were examined as follows: pH 7.0, MgFeO@BC of 0.4 g/L, PMS concentration of 0.6 mM and SMX concentration of 10.0 mg/L at 25 ℃. In the MgFeO@BC/PMS system, the removal efficiency of SMX was 99.0% in water within 40 min under optimal conditions. In the MgFeO@BC/PMS system, the removal efficiencies of tetracycline (TC), cephalexin (CEX), ciprofloxacin (CIP), 4-chloro-3-methyl phenol (CMP) and SMX within 40 min are 95.3%, 98.4%, 98.2%, 97.5% and 99.0%, respectively. The radical quenching experiments and electron spin resonance (ESR) analysis suggested that both non-radical pathway and radical pathway advanced SMX degradation. SMX was oxidized by sulfate radicals (SO4•-), hydroxyl radicals (•OH) and singlet oxygen (1O2), and SO4•- acted as the main active species. MgFeO@BC exhibits a higher current density, and therefore, a higher electron migration rate and redox capacity. Due to the large number of available binding sites on the surface of MgFeO@BC and the low amount of ion leaching during the catalytic reaction, the system has good anti-interference ability and stability. Finally, the intermediates of SMX were detected.

Silica coated N-doped carbon modified with ruthenium nanoparticles: An effective waste derived carbon nanocatalyst in oxidation reactions and also its evaluation by DFT and anti-bacterial studies

This report presents the development of an inexpensive mesoporous nanocatalyst i.e. silica coated N-doped carbon modified with ruthenium nanoparticles (Ru/RuO2@NSAC). The carbon and nanosilica components were derived from waste materials namely waste tea extract and rice husk respectively highlighting the sustainable approach to the synthesis process. The nanocatalyst was thoroughly characterized using various advanced techniques such as Fourier transform infrared spectroscopy (FTIR), Powder X-ray diffraction (P-XRD), Field emission gun-scanning electron microscopy (FEG-SEM), Energy dispersive X-ray analysis (EDX), High resolution-transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) surface area analysis, X-ray resonance fluorescence (XRF) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). These characterizations provided comprehensive insights into the structural features of the nanocatalyst. XPS analysis confirmed the presence of both metallic ruthenium and Ru (IV) on the nanocatalytic support. The particle size of Ru/RuO2@NSAC was determined using Scherrer's equation and came out to be 21.37 nm. This nanocatalyst demonstrated remarkable performance as a robust heterogeneous catalyst for the oxidation of alkylarenes and alcohols to their corresponding carbonyl compounds. It exhibited excellent recyclability, maintaining its activity for up to five consecutive runs. Post-recycling, the catalyst was again characterized by P-XRD and FEG-SEM to ensure its structural integrity. Additionally, the antibacterial activity of Ru/RuO2@NSAC was evaluated against both Gram-positive and Gram-negative bacteria. A density functional theory study was also conducted to support the experimental findings, providing a theoretical basis for the observed catalytic behavior.

Co-valorisation of cassava peel and rice husk to biofuel precursor via intermediate pyrolysis: Kinetics, thermodynamic and pyrolytic oil characterisation

Co-valorisation of cassava peel and rice husk to biofuel precursor via intermediate pyrolysis: Kinetics, thermodynamic and pyrolytic oil characterisation

Rice husk ash and recycled sand as synergistic substitutes in ultra-high performance concrete: Microstructural, mechanical performance, and eco-economic analysis

Quartz sand and silica fume (SF), commonly used in UHPC production, are costly and contribute to dust pollution and significant carbon emissions. In this work, we explored the preparation of an environmentally friendly ultra-high performance concrete (e-UHPC) by substituting SF and quartz sand with rice husk ash (RHA) in ratios of 10 %, 20 %, and 30 %, and recycled building sand (RS) in ratios of 25 %, 50 %, and 75 %. We assessed the impact of these substitutions on workability, mechanical strength, hydration products, and the micromechanical characteristics of the interfacial transition zone. In addition, an environmental and economic assessment index for e-UHPC was introduced. Results showed that while RHA and RS reduced the flowability of e-UHPC, RHA helped mitigate the compressive strength loss due to RS (3.9 %-9.7 %). RHA accelerated early hydration, and improved densification in the transition zone, enhancing late hydration and refining the pore structure of e-UHPC. Notably, a 10 % RHA replacement rate optimally improved early hydration efficiency and minimized CH content. The combination of 10 % RHA and 25 % RS proved most effective in optimizing the interfacial transition zone and improving the pore structure of e-UHPC. Importantly, e-UHPC reduces the carbon footprint at a lower cost and offers significant environmental and economic advantages over traditional UHPC. The results of this study will promote the incorporation of construction and agricultural wastes into concrete.

Multifunctional and novelty green composite film containing sodium alginate, chitosan, rice husk and curcumin

Foodborne diseases are a global public health issue, with their causes often originating from lapses in food production or transportation leading to food contamination. Therefore, food packaging plays a crucial role in preserving the safety and quality of food. In pursuit of sustainable development, this study aims to utilize agricultural waste-derived functional mesoporous silica nanoparticles in combination with biodegradable molecules to create food packaging films. Through recycling and the use of environmentally friendly green films, the goal is to achieve sustainability and the objectives of green chemistry. The study anticipates the production of biodegradable films and the testing of their antibacterial capabilities, antioxidant properties, biocompatibility, and film stress coefficients. This research will provide robust support for advancing green packaging technology to address the challenges of global food safety and environmental sustainability.The experiment is divided into two parts. The first part involves the synthesis of multifunctional mesoporous silica nanoparticles with antibacterial properties derived from rice husk (Rice husk mesoporous silica nanoparticles, rMSN) as nano-fillers. These nanoparticles are surface modified with a biodegradable polymer, chitosan (Chi), that interacts with the material. Natural extract curcumin (Cur), known for its antioxidant capabilities, is loaded into the pores, and the material's inherent antibacterial properties are utilized. The second part involves blending the material with the natural polymer sodium alginate (SA) to form a film (rMSN-Chi@Cur/Alg film). The film's thickness, stress strength, antibacterial, and antioxidant capabilities are tested to ensure the material possesses antibacterial and antioxidant properties.

Computational Prediction of Co-firing with Various Biomass Waste Using Turbulent Non-Premixed Combustion

Co-firing in coal power plants has limitations because the existing combustion systems are designed to provide optimal performance only with coal. Therefore, investigating the combustion aspects of co-firing by mixing coal with biomass before applying it to existing coal power plants is necessary. To address this, a new numerical model was developed to predict the co-firing behavior of coal with various types of biomass waste, specifically focusing on temperature and pollutant behavior. This study developed a co-firing model in a Drop Tube Furnace (DTF) using a composition of 25% Wood Chips (WC), 25% Solid Recovered Fuel (SRF), 25% Empty Fruit Bunch Fibers (EFFR), and 25% Rice Husk (RH). A structured grid arrangement and the Probability Density Function (PDF) were utilized to depict the relationship between chemical combustion and turbulence. The distributions of temperature and mass fractions of pollutants along the furnace axis were predicted. The highest temperature was observed with 25% EFFR, attributed to its highest volatile matter content. The simulation predicted that 25% RH would be the lowest SO2 emitter. However, it also showed a slight increase in NO and CO levels due to the increased oxygen content when coal was mixed with biomass. The simulation with 25% EFFR predicted a decrease in CO2 emissions compared to other biomass types. The results of this parametric investigation could support the implementation of biomass co-firing technology in existing coal-fired power plants.

Influence of Trenchless Subsurface Drainage with a Rice Husk Filling System on Soybean Productivity Under a Poorly Drained Paddy Field for Future Applications in Smart Agriculture

In South Korea, paddy fields are increasingly being planted with soybeans to address rice supply and demand issues and increase soybean self-sufficiency. The field crops cannot grow healthily without adequate drainage due to the paddy fields storing water easily. In this study, we identified that Rice Husk Filling Drainage Method (RHDM) technology improved soil permeability and soil aeration. We also found that the soil moisture content was reduced and the water table remained at a lower level in the RHDM plot as compared to the control plot. The soybean moisture stress index showed that in the RHDM plot, the safety standard for stress due to excessive moisture at the 2 m interval was met. The soybean yield was increased by up to 35% in the 2 m RHDM construction interval compared to the control plot. In addition, the high hydraulic conductivity of the rice husk used as the hydrophobic material confirmed sufficient drainage performance and was considered economically advantageous. Therefore, our results show that RHDM is a highly efficient and economical drainage method in poorly drained paddy soils. Drainage management is essential for stable crop production in poorly drained paddy fields. Our research findings suggest that an efficient open field water management method is viable, which we believe will lead to future advances in open field smart agriculture.

Evaluating mechanical performance of coconut fibre reinforced polymer composites with variable fibre content

The rapid growth of composite materials, leveraging natural ingredients such as dried fruit, rice husk, wheat husk, straw, and hemp fibres, has expanded their applications and market presence. Among these, coconut fibre stands out due to its high tensile strength, making it a promising reinforcement for polymer composites. However, increasing the coconut fibre content can reduce the cohesion and some properties of the composites. This study investigates the impact of the weight percentage of coconut fibres on the mechanical properties of coconut fibre-reinforced composites. Various composites were prepared with different weight percentages of coconut fibre, and their mechanical properties were evaluated using tensile tests with a Universal Testing Machine Instron 8872 and hardness tests with a Digital Shore Scale “D” Durometer. The results indicate significant changes in tensile strength, tensile strain, and hardness corresponding to the weight percentage of coconut fibre. This research highlights the importance of optimizing fibre content to achieve balanced mechanical properties in coconut fibre-reinforced composites.

Nano Powder SiO2 from Rice Husk and its Industrial Applications: A Concept of Wealth from Waste

The rice Husk (RH) is a renewable biomass product and through thermochemical processes like pyrolysis and gasification, silica-rich RH is transformed into biofuels (such as bio-oil, vapors, and charcoal) and biochar at the same time. RH catalysts can convert bio-oil into more renewable biofuel (biodiesel). Using RH silica materials to purify gas or undergo catalytic reforming, vapors from the breakdown of organic waste can be transformed into syngas, which have more value and can be utilized to create energy or make chemicals. Biochars created from RH are usually used to produce materials for silicon batteries, mend soil, clean up pollutants, and accomplish other things. This study looked at recent improvements in how RH silica products are created and how they can be used in the future, notably in manufacturing materials that benefit the environment and save energy. RH-silica compounds have environmental benefits, can eliminate organic and heavy metal contamination through integrated processes and adsorption, and are used as a catalyst in fertilization, and water purification, including gas cleaning. Lastly, biomass with a lot of silica could be a source of cheap starting materials for creating high-value silica/silicon compounds that can be employed in the actual world.

Synthesis of Mesoporous ZnO•SiO2 Nanocomposite from Rice Husk for Enhanced Degradation of Organic Substances Including Janus Green B under Visible Light

Rice husk (RH) is often mentioned as an agricultural by-product, often used in the pass as fertilizer and for raw burning. With modern science, RH have been researched and found many new potential benefits and applications. In this study, RH were used to synthesize amorphous SiO2, which was used to prepare the ZnO•SiO2 nanocomposites by a hydrothermal method. The as-synthesized materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and N2 adsorption/desorption isotherm. Their photocatalytic properties were studied by an ultraviolet-vis spectrophotometer and a fluorescence spectrophotometer. The ZnO•SiO2 nanocomposite has an excellent ability to degrade organic substances such as dyes, antibiotics, caffeine, etc. The effects of operating parameters on the photo-degradation reaction progress, including catalyst dosage, initial dye concentration, and pH of the initial dye were investigated in detail. In addition, the photodegradation rate of the dye on the ZnO•SiO2 nanocomposite was evaluated using the pseudo-first-order model. The ZnO•SiO2 nanocomposite can be used as a photocatalyst for wastewater treatment as it detaches much more easily from the solution. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Electrochemical conversion of rice husk in molten salts to photocatalyst for CO2 photoreduction

Photocatalysts obtained from waste biomass by molten salt electrolysis can photocatalytically reduce carbon dioxide under simulated photosynthesis, which is of great significance for carbon neutrality. Herein, a molten-salt electrochemical synthesis strategy that silicon-carbide nanowires mixed carbon (SiC/C) is obtained at the cathode by absorption of molten salt and migration in molten salt with the rice husk (RHs) is especially used as the anode is reported. This study shows the excellent absorption and migration effect of molten salt on RHs pyrolysis products SiO2 and CO2. At the same time, the unilateral consumability of the anode is more advantageous in device design. The obtained SiC/C photocatalyst has an excellent performance in photocatalytic reduction of CO2.

Performance evaluation of untreated sugarcane bagasse ash as partial replacement of cement on setting time and compressive strength of M15 concrete

Due to its escalating cost, cement, the primary component of concrete, has become a significant issue in Nigeria over time. The use of agricultural wastes such as cow bones, periwinkle shells, rice husks,and sugarcane bagasse as additives to partially replace cement has been made possible by scientific efforts to find alternative and effective materials from large deposits of agricultural wastes. This study examines how adding sugarcane bagasse ash (SCBA) to concrete affects its strength properties. Sugarcane bagasse ash was successfully included in various amounts (0, 2.5, 5.0, 7.5, and 10% by weight of cement). A mix design of 1:2:4 (M15) grade and a water-cement ratio of 0.5 was used to cast 60 concrete cubes measuring (150 x 150 x 150) mm. Concrete's workability and setting time were improved by adding sugarcane bagasse ash to the cement. The outcome revealed a reduction in concrete density with an increase in percentage replacement of sugarcane bagasse ash. Addition of sugarcane bagasse ash to cement increased the concrete's workability and speed of setting. The results showed that concrete density decreased as sugarcane bagasse ash replacement percentage increased. This is not unrelated to the fineness of sugarcane bagasse ash, which makes the cementitious matrix and aggregate interface more intense and lighter. Concrete's compressive strength was discovered to be decreased by the usage of sugarcane bagasse ash. Between 0, 2.5, 7.5, and 10% sugarcane bagasse ash, the average compressive strength measured at 28 days was found to be 25.93, 25.19, 23.70, 20.30, and 18.96 MPa, respectively. 10% sugarcane bagasse ash concentration was suggested as the optimal level to employ for improving concrete characteristics.

A novel red emitting Eu3+ doped CaSiO3 nanophosphor derived from agro-wastes for advanced forensic applications

The modified sol–gel approach was utilised to synthesise Eu3+ (1–5 mol%) doped CaSiO3 nanophosphors (NPs) using eggshell (ES) and rice husk ash (RHA) as precursors for SiO2 and CaO, respectively. Powder X-ray diffraction (PXRD) peaks confirm the monoclinic structure of the powdered samples. The photoluminescence (PL) emission spectra display distinct emission peaks corresponding to Eu3+ ions. After optimizing the Eu3+ ion concentration, the highest intensity (CaSiO3:3Eu3+) was achieved at 3 mol%. As the concentration increased beyond this point, the emission intensity decreased due to concentration quenching (CQ). Temperature-dependent photoluminescence (TDPL) was investigated in the range of 303 to 443 K. The results demonstrated that emissions at elevated temperatures are significantly stronger than those at ambient temperature. TDPL studies revealed excellent thermal stability, with emission intensity remaining at 87.5 % even at 423 K. Additionally, the phosphor’s absolute sensitivity of 0.003 K−1 and relative sensitivity of 1.44 % K−1 highlight its strong potential for temperature sensing applications. The suitability of the phosphor for the powder dusting method in fingerprint (FP) detection on various surfaces was also assessed. Under 365 nm UV light, the CaSiO3:3Eu3+ phosphor clearly reveals the level 1–3 structure of LFPs.

Comparison of composition, properties and modifying effect in epoxy compositions of natural and synthetic diopside-containing fillers

Diopside is one of the key components in various construction materials and can also be used as a filler for epoxy compositions. However, due to the complexity and labor intensity of developing domestic deposits of this calcium magnesium silicate, it is rational to synthesize diopside based on rice husk ash and dolomite and compare its phase composition and properties with diopside concentrate mined in nature.It has been established that the synthesized calcium-magnesium silicate, compared to the natural mineral, contains 10 times more diopside, has a 3 times smaller pore volume and an almost 5 times smaller average particle size, i.e. they differ significantly in both phase and granulometric composition, as well as in porosity.At the same time, both natural and synthetic diopside-containing fillers increase the hardness, wear resistance and viability of epoxy compositions. A filler synthesized on the basis of rice husk ash is more effective in terms of increasing the performance characteristics of epoxy materials.

Comparative Study of the Physical, Chemical, Mineralogical and Morphological Properties of Two Types of rice husk ash for use in Building Materials

Comparative Study of the Physical, Chemical, Mineralogical and Morphological Properties of Two Types of rice husk ash for use in Building Materials

Removing emerging organic pollutants (oxytetracycline) by engineered biochars originated from agricultural wastes

AbstractEngineered biochars derived from five types of agricultural by‐products—macadamia nut shells, rice husks, durian peel, coir, and straw—were synthesized using a hydrothermal method combined with pyrolysis for oxytetracycline (OTC) treatment. N2 and CO2 adsorption–desorption, FE‐SEM (Field Emission ‐ Scanning Electron Microscopy) and FTIR (Fourier‐transform infrared spectroscopy) results were utilized to characterize their properties. While the surface elements and functional groups of these five biochars were relatively similar, significant differences were observed in their porous structures. Batch and continuous adsorption studies provided valuable insights into the dynamic behavior of biochar materials in the removal of OTC, highlighting variations in performance among different biochar types and emphasizing the importance of sustained efficacy over multiple cycles for practical applications. Coir biochar demonstrated the highest OTC adsorption capacity, achieving 93% in batch adsorption and exhibiting complete OTC treatment after eight reuse cycles. Durian peel and straw biochars also exhibited strong performance in both batch and continuous adsorption. However, rice husk and macadamia nut shell biochars displayed lower efficacy in OTC treatment. The dominant mechanism for adsorption appears to be pore filling, facilitated by Van der Waals forces between OTC molecules and the walls of micro‐mesopore structures within the range of 1.2–10 nm.Statement of Industrial RelevanceThe study's findings are pivotal for innovating, modeling, and designing effective systems to remove emerging organic pollutants from water.Novelty or SignificanceA straightforward, easily scalable, and sustainable solution has been introduced for treating emerging organic pollutants from water, utilizing engineered biochars derived from agricultural wastes.Plain Language SummaryIn this study, we explored the use of engineered biochars made from agricultural by‐products to treat a common antibiotic pollutant, oxytetracycline (OTC), in water. We created these biochars from materials like macadamia nut shells, rice husks, durian peel, coir, and straw using a special method. By analyzing their properties, we found that although these biochars had similar chemical surface features, they differed significantly in their overall porous structure. Some of these engineered biochars were effective in removing OTC from water, both in controlled lab conditions and in real‐world scenarios. Specifically, coir biochar showed the best results, removing 93% of OTC in lab tests and staying effective even after being reused multiple times. Durian peel and straw biochars also performed well. However, rice husk and macadamia nut shell biochars were less effective in removing OTC. We found that the main way these biochars removed OTC was by filling up tiny pores in their structure, which trapped the OTC molecules. This study provides valuable insights into using biochars to clean up water polluted with antibiotics, offering a sustainable and practical solution for water treatment.

Rice Husk as a Sustainable Amendment for Heavy Metal Immobilization in Contaminated Soils: A Pathway to Environmental Remediation

Rice husk is a waste byproduct of rice production. This material has a moderate cost and is readily available, representing 20–22% of the biomass produced by rice cultivation. This study focused on the properties of rice husk in the remediation of soils contaminated by heavy metals. The effect of particle size, pH, and the presence of organic ligands on sorption efficiency was evaluated for Cd, Cu, and Mn. The continuous flow method was used to select suitable operative conditions and maximize the retention of heavy metals. Subsequently, pot experiments were carried out by growing two broadleaf plants, Lactuca sativa and Spinacia oleracea, in aliquots of soil collected in a Piedmont (Northwest Italy) site heavily contaminated by Cu, Cr, and Ni. Rice husk was added to the contaminated soil to evaluate its effectiveness in immobilizing heavy metals. The availability of Cr, Mn, Ni, Cu, Zn, Cd, and Pb in soil was studied using Tessier’s sequential extraction protocol. The content of the elements was also analyzed in plants and the uptake of heavy metals was evaluated in relation to the addition of rice husk. The growth of both plants was more efficient in the presence of rice husk due to its ability to reduce the mobility of heavy metals in the soil. The simplicity, cost-effectiveness, and scalability of its employment make the use of rice husk suitable for practical applications in soil remediation.

Exploring the traits and possible ecological risks of heavy metals in biochars derived from rice husk and sugar beet pulp.

This research investigated the properties and potential environmental hazards associated with biochars derived from rice husk (RH) and sugar beet pulp (SBP), both of which are rich in heavy metals (HMs). The results indicated that the concentration of various HM fractions is significantly affected by the type of feedstock and the pyrolysis temperature. Specifically, the total concentrations of HMs in biochars produced at 600°C were found to be 10-140% higher than those in the original biomasses, a phenomenon attributed to the precipitation of HMs. Cd was a notable exception, exhibiting a reduction of 3-7% in the resultant biochars when compared to biomass, likely attributable to its volatilization. The results also revealed that the F1 + F2 fraction of HMs were largely transformed into F3 + F4 fraction during combustion, indicating that pyrolysis may reduce the ecotoxicity of HMs present in contaminated biomass. However, the process did not effectively diminish the F1 and F2 fractions of Cr and Cd. Elevated pyrolysis temperature significantly enhanced the reduction of HMs phytoavailability. Specifically, the phytoavailability of HMs in biochars produced at 600°C exhibited a decrease ranging from 10 to 92% when compared to the original biomass. Conversely, an unexpected rise in the phytoavailable fractions of Cr and Cd was noted in both RH and SBP biochars as the pyrolytic temperature increased, which correspondingly raised the potential ecological risk index (PERI). All materials analyzed exhibited a very high risk level, with PERI values exceeding 800, primarily due to the significant toxicity of Cd. Excluding Cd from consideration, the biomasses and their resultant biochars displayed PERI values ranging from 7 to 13. It is important to acknowledge that pyrolysis may not effectively diminish the environmental toxicity associated with HMs present in contaminated biomass, thereby limiting its safe application.

Caffeine removal from water using rice husk residue biochar: characterization, kinetics and sorption isotherms

Caffeine removal from water using rice husk residue biochar: characterization, kinetics and sorption isotherms

Influence of water scouring on chloride ion diffusion in rice husk ash recycled aggregates concrete

This study investigates the chloride ion diffusion behavior in concrete incorporating rice husk ash (RHA) and recycled aggregates (RA) under water scouring conditions. The research results indicate that both free and total chloride ion concentrations in recycled aggregate concrete (RAC) exhibit an initial increase, followed by a subsequent decrease, as the distance from the concrete surface increases. The incorporation of RHA reduces both free and total chloride ion concentrations while increasing bound chloride ion content. However, an excessive amount of RHA can weaken the resistance of RAC to chloride ion penetration. Water erosion deteriorates the internal microstructure of RAC, accelerating the transport of free and total chloride ions. However, it does not compromise the chloride ion binding mechanism conferred by RHA. The fine particulate of RHA provides additional nucleation sites for cement hydration, while the reservoir effect ensures a steady supply of free water to these sites. This synergistic interaction enhances the pozzolanic reaction between cement hydration products and RHA, resulting in reduced Ca(OH)₂ content and increased formation of C-S-H gel.