Rice Husk Research Articles

Additive effects of rice husk-based carbon-silica composites on adsorption of diclofenac sodium and carbamazepine from aqueous solutions

The present study investigated the adsorption of diclofenac sodium (DCF) and carbamazepine (CBZ) on carbon-silica composites (CSC), activated carbon (RH-AC) and biogenic silica (RH-BS) based on rice husks from aqueous solutions. The materials were characterised using scanning electron microscopy, infrared spectroscopy, inductively coupled plasma optical emission spectroscopy, nitrogen sorption and elemental analysis. These methods provided essential information on the morphology, chemical composition, textural properties and surface characteristics of porous materials. The results of the adsorption studies demonstrate that the investigated materials exhibit varying adsorption capacities for DCF and CBZ. The maximum adsorption capacity was achieved by CSCs, with 1111 mg g−1 for DCF and 455 mg g−1 for CBZ and indicates additive effects on the adsorption capacity of CSCs compared to RH-AC and RH-BS. In addition to the hydrogen bonds and the π-π electron donor-acceptor interactions of the carbon component, further hydrogen bonds are formed by the silanol groups of the silica component. The CSCs derived from rice husks represent an innovative approach to the more efficient removal of pharmaceutical residues from wastewater. This is accomplished by utilizing a single starting material for both components, thereby yielding a unique structural combination.

Pyrolysis kinetics and thermodynamic analysis of bamboo, bagasse, and rice husk bio-chars: Implications for sustainable energy

This study focuses on the kinetic and thermodynamic analysis of bio-chars derived from popular and abundantly available biomasses like bamboo, bagasse, and rice husk. These bio-chars obtained by pyrolysis aim to be utilised without any refinement for combustion purposes minimising greenhouse gases and contributing towards sustainable development goals. However, understanding the kinetic and thermodynamic properties of bio-char is essential for optimizing its combustion performance. The results indicate a marked improvement in fixed carbon content and calorific value compared to the original biomass, alongside a reduction in average activation energy. For example, bamboo bio-char exhibited an increase in fixed carbon content from 16.02 % to 68.28 %, a rise in higher heating value from 16.84 to 25.48 MJ/kg, and a decrease in average activation energy from 183.63 to 121.22 kJ/mol in comparision to bamboo biomass. Additionally, the study introduces a novel approach that combines model-free and model-fitting techniques to simultaneously determine the reaction mechanism and pre-exponential factor such that the need for separate validation ends. This novel methodology offers a state-of-the-art framework for assessing the bioenergy potential of various biomasses, applicable for studies and comparisons on a global scale.

Torrefaction Integrated with Steam Gasification of Agricultural Biomass Wastes for Enhancing Tar Reduction and Hydrogen-rich Syngas Production

Steam gasification is considered as a promising technology for conversion of various biomass wastes to valuable hydrogen (H2)-rich gas products that can be applied for the sustainable production of green hydrogen and methanol. However, some inevitable problems such as high tar content and low cold gas efficiency greatly hinder its broad application. Torrefaction has been widely employed for upgrading low-rank biomass sources that favors the follow-up gasification process, resulting in low tar yield and high syngas yield. Torrefied biomass usually shows higher energy density, improved grindability characteristics, and lower O/C and H/C ratios. This research work studies the effect of torrefaction on steam gasification of corncob (CC) and rice husk (RH). The mechanisms of biomass torrefaction integrated with steam gasification are also given. Biomass torrefied at a relatively high temperature (280 oC) is more efficient to extract the oxygenated volatiles, reducing the generation of tar and particulate matters during the gasification process. The increase of torrefaction temperature resulted in an increase of H2 yield and a decrease of CO yield, corresponding to an increase of H2/CO ratio. Particularly, the H2 yield in the CC-derived syngas increased from 6.38 mmol/g (raw) to 12.01mmol/g (280 °C), and the H2 yield in the RH-derived syngas increased from 4.33 mmol/g (raw) to 12.97 mmol/g (280 °C). Steam gasification of RH torrefied at 280 oC achieved a maximum H2/CO ratio of 2.84. After torrefaction of CC and BB at 280 °C, the tar yield of steam gasification was below 1% [gasification temperature: 800 °C, mass ratio of steam to biomass (S/B): 1]. In general, the torrefaction pretreatment of biomass at relatively high temperatures (i.e., 280 oC) favors the steam gasification process under an appropriate S/B (i.e., 1) in terms of improving the syngas quality and reducing the tar production.

Pyrolysis of biomass mixture of coconut fiber and rice husk waste with polypropylene plastic

Pyrolysis of biomass mixture of coconut fiber and rice husk waste with polypropylene plastic

Harnessing waste for sustainable construction: A novel synthesizing activators from waste for one-part geopolymer concrete and evaluating its fracture toughness

Geopolymer concrete garners significant attention due to its potential to mitigate pressing global challenges, such as CO2 emissions and waste management for disposal. However, using more expensive commercial activators has posed a significant obstacle to practical implementation. Therefore, scientists want to develop methods to extract powdered activators from agricultural and industrial waste materials. To this end, the study has sought to create innovative activators derived from waste glass powder (WGP) and silica-rich rice husk ash (RHA) to create one-part geopolymer concrete (OPGC). Ground granulated blast-furnace slag is utilized as a precursor material for preparing binder, with varying ratios of WGP/RHA to sodium hydroxide (NaOH) from 0.50 to 1.75 at 0.25 intervals. Twenty-four distinct mixtures of OPGC were prepared using the materials mentioned above and evaluated for their compressive strength and fracture toughness. The primary objective of this research is to evaluate the mode I, III, and I/III fracture toughness of OPGC using edge-notched disc bend specimens. Additionally, a 1 % steel fiber dosage was introduced into the OPGC to reduce brittleness. The microstructural characteristics were examined through X-ray diffraction and scanning electron microscopy. Findings reveal that the fracture toughness of OPGC improves with the RHA to NaOH ratio up to 1.0, peaking at 1.09 MPa·m^0.5. Likewise, the fracture toughness increases with the WGP to NaOH ratio up to 0.75, reaching a peak value of 1.20 MPa·m^0.5. Beyond these respective ratios, a decrease in fracture toughness was observed. Nonetheless, incorporating fibers into OPGC consistently improved the fracture toughness across all mixtures. Mode I fracture toughness is greater than I/III and III, emphasizing the significance of Mode III compared to other fracture modes.

Two plant extracts protect stored maize against infestation of Sitophilus zeamais in Northern Ghana

Botanicals have been encouraged as substitutes for conventional pesticides to reduce the impact of the latter on the environment. In line with that, we studied the effects of two plant extracts in controlling Sitophilus zeamais Motsch (Coleoptera: Curculionidae) attacks on stored maize (Zea mays L. Poales: Poaceae). The experiment was conducted under a normal room temperature of 27⁰C to 30⁰C and relative humidity of 74% to 76% in a completely randomized experimental design. We infested the stored maize seeds in glass jars with S. zeamais F1 under a 12-hour day and 12-hour night within 24hours period. This was after 50g of the seeds were mixed with 2g each of the two botanicals separately in different glass jars. There were 5 treatments and 10 replications in total. The data taken for this study were quantitative. To ascertain the efficacy of the botanicals we compared the number of dead and live weevils, of seeds damage and weight loss caused by weevil attacks under each of the different treatments by determining percentage mortality, percent weight loss, seed damage and progeny production. Our results showed that the different botanical formulations significantly controlled S. zeamais population resulting in reduced damage, better protection and improved storage of maize seeds. However, there were no significant differences in protections offered between shade dried neem seed powder and rice husk powder although the latter was the most efficacious with 85% mortality compared to the former with 65% with sundried neem seed powder being the least with a little above 40% mortality. We concluded from this study that the formulated botanicals were very effective in controlling S. zeamais populations and therefore recommended that it be used as a cost effective and environmentally friendly protection of stored maize against S. zeamais attacks, especially in rural poor areas and places known for continuous seed production and storage, such as the case of the study community.

Effect of the incipient anode in concrete patch repair using mortars with rice husk ash (RHA) on substrate contaminated by chlorides

Resumo Após a realização de reparos localizados, costuma-se observar o ressurgimento de pontos de corrosão na região adjacente à área reparada, situação usualmente denominada ânodo incipiente. Embora tenham sido feitas diversas pesquisas a respeito do tema, ainda restam controversos aspectos em relação às suas causas, localização e progressão no tempo. Com objetivo de investigar essas lacunas no conhecimento, moldaram-se amostras com substrato contaminado por cloretos não reparadas e reparadas com argamassa de reparo contendo substituição de ligante por sílica de casca de arroz (SCA) nos teores de 0%, 10% e 20%. Em seguida, realizaram-se aferições das variáveis eletroquímicas de densidade e potencial de corrosão, bem como a inspeção destrutiva de parte das amostras. Após as aferições, observou-se aumento nas densidades de corrosão após o reparo, na interface substrato-reparo. Na inspeção destrutiva, também foi constatada deterioração significativa na interface reparo-substrato, bem como em algumas regiões no interior do substrato. Em relação ao efeito da substituição de ligante por SCA, não foi identificada redução relevante do ânodo incipiente nas argamassas com 10% e 20% de SCA. Por outro lado, notou-se possível redução da capacidade de passivação da argamassa com teor de 20% de SCA.

Development of rare earth doped SiO2/rGO from rice husk for antioxidant, photocatalysis, electrochemical and sensor studies

The present work determines the synthesis of cerium loaded silicon dioxide (Ce-SiO2/rGO) nanocomposite by using reflux method. The Ce-SiO2/rGO was confirmed by using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive (EDAX) techniques. In photodecomposition investigation, Rose Bengal (RB) dye was degraded efficiently using Ce-SiO2/rGO nanocomposite (95 %) at 150 min with follows first order kinetics. The antioxidant property against 2,2-diphenyl-1-picrylhydrazyl (DPPH) was found to be 98 % performance with IC50 value of 488.35 mg/mL. The super capacitance value of Ce-SiO2/rGO was increased compared to that of rGO, SiO2 and SiO2/rGO respectively. The electrochemical reversibility (EO−ER) and diffusion coefficient (D) values were determined using 1 M KCl by cyclic voltammetry method. Ce-SiO2/rGO nanocomposite was used as an electrochemical sensor to detect bee pollen and cow urine. The produced material has superior dye purification, redox behavior, bio-molecule detection, and antioxidative capabilities.

Polyamide 6 Recycled Fishing Nets Modified with Biochar Fillers: an Effort Toward Sustainability and Circularity

In a further research effort toward sustainability and circularity, this work demonstrates the possibility of designing and producing novel blends derived from recycled polyamide 6 (PA6) fishing net, incorporating two biochars, i.e., carbonaceous materials obtained from the controlled pyrolysis of vegetable biomasses, at different loadings (namely 5, 10, and 15wt.%). The biochar derived from lignocellulosic biomass enhanced both the mechanical properties and moisture resistance of the recycled polyamide, increasing the elastic modulus from 2.6 to 4.5GPa and reducing water uptake from 3.6 to 1.8%. Interestingly, thanks to its high silica content, the biochar derived from rice husk accounted for an increase in the activation energy for combustion of the polymer matrix (from 43.6 to 70.9kJ/mol). However, it also showed a detrimental effect on the water uptake and the mechanical behaviour of the blends. Besides, the possibility of replacing up to 15wt.% of petroleum-derived carbon black pigments with the biochars decreased the overall cost of PA6 blends. Also considering the biochar densities that are lower than those of traditional carbon fillers, the proposed blends may pave the way for the design, development, and exploitation of novel sustainable materials suitable for lightweight applications.

Combine the use of rice husk ash and quarry waste for sustainable masonry blocks: mechanical characteristics, durability and eco-benefits

The construction industry faces a growing demand for eco-friendly practices. This study explores the viability of incorporating quarry waste and rice husk ash (RHA) as partial replacements for cement and river sand in masonry block production. The research investigates the combined effect of these waste materials on the critical characteristics of cement blocks, including physical properties, mechanical behaviour, and resistance to environmental degradation. A cost-benefit analysis also considers economic, environmental, and societal factors. Replacing river sand with quarry waste in the mortar mix resulted in higher density and improved impact resistance. Also, it exhibited lower water absorption and early-age strength than the river sand. Partial cement replacement with RHA yielded positive results at lower incorporation levels. Up to 20% RHA content enhanced compressive and flexural strength while reducing embodied energy and CO₂ emissions. However, higher RHA replacements negatively affected these properties. The optimal balance between cost-effectiveness, environmental benefits, and structural performance was achieved with a combination of 20% RHA and complete quarry waste replacement. This approach offers a sustainable and potentially cost-saving alternative for conventional masonry block production. This research demonstrates the potential of utilizing waste materials in construction while promoting eco-friendly practices and responsible waste management in the industry.

Dy doped calcium silicates synthesized using agro-food wastes and conventional chemicals as resources: a comparative study

Based on an earlier study, a mimic composition 38SiO2-60CaO-0.5Dy2O3-0.2Na2O-1MgO-0.1Al2O3-0.1TiO2-0.1Fe2O3 (wt.%) are synthesized by solid-state reaction method. The structural, morphological, and optical properties of the synthesized sample presented in this study are compared with the corresponding properties of a similar sample derived from rice husk ash and eggshell powder as resources. The conventional chemicals derived sample are multi-phasic, containing β−Ca2SiO4, γ−Ca2SiO4, Ca3Si2O7, and CaFeO3 phases, and the CaO/SiO2 ratio was believed to be affecting the room temperature stabilization of the β phase. Field emission scanning electron microscopy images showed that twinned particles, cracks, and edge dislocations were present in the synthesized sample. The presence of precipitates in the micrographs indicated that Dy ions were segregated on the surface of the sample. The optical bandgap of the samples was 3.7 eV, as calculated by diffuse reflectance spectroscopy. The photoluminescence emission spectrum contained characteristic emission peaks of the Dy3+ ions. Apart from these, additional peaks were observed due to the titanium ions present in the sample. Understanding the properties of calcium silicates containing multiple dopant ions is important to develop a white light-emitting diode. The properties of the mineral-derived sample are compared to those of the agro-food waste-derived similar sample.

Environmental Management Practices and Sustainable Green Concrete Use in Malaysia's Construction Industry: Challenges, Benefits, and Future Directions

This review examines the environmental management practices (EMPs) employed within Malaysia's construction sector, with a particular focus on sustainable practices and the adoption of green concrete, including fly ash, rice husk ash, and palm oil fuel ash varieties. The study identifies key challenges, such as low awareness, high costs, weak legal enforcement, and the underdevelopment of green materials in the country. To address these issues, the report proposes solutions such as capacity-building programs, government incentives like tax breaks and grants, regular site inspections, and investment in research and development of green materials. The review also assesses the advantages and limitations of different green concrete types used in Malaysia. The aim of this study is to enhance sustainability efforts and reduce the environmental impact of construction activities through greater awareness, stronger regulatory support, and commitment from all stakeholders. Implementing greener concrete and EMPs is expected to not only mitigate environmental concerns but also yield long-term economic benefits for Malaysia.

The Influence of Rice Husks, Coconut Shells, and Sugarcane Bagasse on the Quality of Bio Briquettes

Coal is a limited natural resource and is found in certain geological locations. Indonesia has abundant mineral and coal resources, with fairly good quality and quantity. The use of coal as fuel has an impact on the environment because CO2 emissions resulting from burning coal can cause a greenhouse effect. One solution to the problem of using coal is the production of alternative energy in the form of briquettes from biomass. This research aims to study the effect of adding a mixture of bagasse, rice husks and coconut shells on the calorific value. The carbon and hydrogen content in biomass greatly influences the water content of the briquettes produced. The increase in carbon content is generally inversely proportional to water content. Briquettes from coconut shell biomass have a higher carbon content than those from rice husks and sugar cane bagasse. The highest calorific value was obtained from coconut shell biomass briquettes, namely 5280.85 cal/g, because briquettes from coconut shells had the highest carbon content, namely 57.18% compared to the carbon content of rice husks and sugar cane bagasse, namely 37 respectively. 24 and 50.04%. Carbon is one of the main components that influences the energy value of briquettes. Although the hydrogen content also contributes to the heating value, its impact is not as big as the carbon content in biomass. The elemental composition of CHNS can affect the water content and calorific value produced. Briquettes from this biomass are only suitable for use as fuel for household purposes.

Assessment of the adsorption capacity of biochar samples obtained from agricultural biomasses

The study consists of adsorption tests on two samples of biochar, obtained from rice husk and coconut fiber biochar biomass, as well as a sample of charcarbon, both prepared under different conditions: macerated and non-macerated; impregnation with and without HCl and H3PO4; and washing or not with deionized water after impregnation. The test was performed in duplicate, for 30 min, with masses of 0.5 g; 0.3 g; 0.1 g; and 0.05 g, and an initial methylene blue concentration of 0.01 g∙L-1. The study was carried out with the objective of identifying, in the analyzed samples, the material with the greatest adsorption capacity of methylene blue dye, comparing the data with commercial activated carbon. The results identified removal above 70 % in both types of biochars, suggesting the feasibility of application as an adsorbent material to remove organic contaminants. The sample that most closely resembled the removal percentage of commercial activated carbon (98.84 %) was that of biochar obtained from coconut fibers, with 91.71 %. Thus, the research showed promise in studying the application and valorization of biochars, produced from agro-industrial waste, in adsorption processes.

The Role and Mechanism of Rice Husk Ash Particle Characteristics in Cement Hydration Process

The Role and Mechanism of Rice Husk Ash Particle Characteristics in Cement Hydration Process

PLASTIC BLOCK FOR BUILDING CONSTRUCTION MATERIAL

Plastic wrap waste increase from time to time. Efforts are needed to utilize them as they are less demanded for recycling by the private sectors in Bali and Indonesia. This paper describe effort to use combination of waste thin plastic wrap as plastic block for wall construction material. The plastic wrap wastes were cut into 5-10 mm size, then they were melted in a hot waste engine oil at 200°C. The mixture was then poured into a metal mold, slightly cooled down and compressed using a compression machine. The mixtures produced was without and with added rice husk ash as filling material. The size of the plastic block was 20×10×8cm. It was found that the densities of the samples were less than 1gram/cm3, the compressive strength can achieve 25kg/cm2, the Porosities were low, ranges from 0.220-0.290%, the Initial Rate of Suctions (IRS) were very low ranges form 0.0004-0.00075 kg/m2.minute, and the and water absorptions were also low (0.02-0.03) %. In general, the compressive strengths were comparable to low quality bricks commonly produced.

Enhanced mechanical and self-healing properties of rice husk ash-incinerated sugarcane press mud biogeopolymer pastes.

This study examines the use of rice husk ash (RHA) and incinerated sugarcane press mud (ISPM) as precursors in the lime/pozzolan geopolymer system and the effect of the bacterium Lysinibacillus sp. WH on the mechanical properties and microstructures. The RHA-to-ISPM ratio was varied, and the geopolymer pastes were cured at ambient temperature. The results show that an increase of ISPM content up to 5% improves strength and reduces water absorption and voids, while higher ISPM levels beyond 5% degrade the quality of geopolymer paste. An increase in ISPM content reduces setting times due to an increase amount of calcium in the pastes. Notably, the addition of bacteria resulting in a reduction of setting times has been proved for the first time in this work. Moreover, the addition of bacteria can enhance all mechanical properties and introduce self-healing abilities, with microcracks healing within < 20 days of treatment, regardless of mix proportions. Microstructural studies, using a scanning electron microscope (SEM), Fourier Transform Infrared Microscopy (FT-IR), X-ray diffraction (XRD), and Rietveld refinement analysis, reveal that bacteria increase cristobalite, and decrease quartz, thus resulting in strength enhancement of geopolymer pastes. Furthermore, this work is the first to provide evidence that bacteria tend to reduce the efflorescence formation as confirmed by a decrease in gaylussite. These findings pave ways to the production of more sustainable geopolymer systems via upcycling wastes and prolonging service life due to bacterial activity.

Laboratory investigation on the bioremediation technology for soilization of iron ore tailings.

The study's objective was to improve the physicochemical properties of iron ore tailings to restore iron ore tailings areas. The physicochemical properties of substrates with different ratios of organic matter and tailings were investigated, and plant growth on these substrates was observed to determine the effects of the mixing ratio on the physicochemical properties of iron ore tailings and identify the optimal mixing ratio. The addition of organic fertilizer and rice husk reduced the density of the substrate, increased the total porosity, and neutralized the alkalinity in the ore tailings. The water-holding capacity of the substrate was positively correlated with the content of rice husk. With increasing rice husk content, the water-holding capacity of the substrates greatly increased, as did the pore structure of the iron ore tailings. The shear strength of the substrates was optimal in Groups I and II, with cohesion peaking in Group II. However, the cohesion sharply decreased as the rice husk content increased, and the internal friction angle decreased. The optimal mixture was 100 g of iron ore tailings, 8 g of organic fertilizer, and 0.8 g of rice husk.

Stabilization Of Clay Soil With Rice Husk Ash And Cement

Stabilization Of Clay Soil With Rice Husk Ash And Cement

Cellulase immobilization on nano-chitosan/chromium metal-organic framework hybrid matrix for efficient conversion of lignocellulosic biomass to glucose

In the current work, cellulase from Aspergillus niger was successfully immobilized on a novel epoxy-affixed chromium metal-organic framework/chitosan (Cr@-MIL-101/CS) support via covalent method using glutaraldehyde as a crosslinker. The bare and cellulase-bound support was characterized by using various microscopic and spectroscopic techniques. Immobilized cellulase exhibited a high immobilization yield of 0.7 ± 0.01 mg/cm2, retaining 87.5 ± 0.04% of its specific activity and displaying enhanced catalytic performance. The immobilized enzyme was maximally active at pH 5.0, temperature 65 °C and 0.9 × 10–2 mg/ml saturating substrate concentration and the half-lives of free and immobilized cellulases were approximately 9 and 19 days, respectively. The decrease in activation energy, enthalpy change, and Gibbs free energy change, coupled with an increase in entropy change upon immobilization, indicated that the enzyme’s efficiency, stability, and spontaneity in catalyzing the reaction were enhanced by immobilization. Additionally, the immobilized cellulase efficiently converted rice husk cellulose to glucose, with a quantification limit of 0.05%, linear measurement ranging from 0.1 to 0.9%, and 8.5% conversion efficiency. The present method exhibited a strong correlation (R2 = 0.998) with the DNS method, validating its reliability. Notably, the epoxy/Cr@-MIL-101/CS-bound cellulase demonstrated impressive thermal and pH stabilities, retaining 50% of its activity at 75 °C and over 96% at pH levels of 4.5 and 5.0 after 12 h. Furthermore, it showed excellent reusability, preserving 80% of its activity after 15 cycles and maintaining 50% of its activity even after 20 days of storage. These results suggest that epoxy/Cr@-MIL-101/CS/cellulase composites could be very effective for large-scale cellulose hydrolysis applications.