Carbonized Rice Husk Research Articles

Study of Mechanical Properties Using Carbonized Rice Husk and Eggshell to Prepare Sustainable Concrete and its Viability in Civil Construction

Sustainability has become an increasingly present concern in the construction industry, which has led to a search for more ecological and sustainable alternatives in the production of construction materials. In this context, research references have shown promising results in the use of carbonized rice husk and eggshell. The use of rice husk as a partial substitute for cement in concrete has proven to be effective in reducing environmental impact, since this residue has pozzolanic characteristics, providing greater resistance to the concrete. Eggshell, in turn, has been used as an additive in the production of mortars, providing improvements in the mechanical and thermal properties of these materials. These sustainable solutions in civil construction are aligned with the ESG agenda of companies, which are increasingly seeking minimize the environmental impact of its activities. The study verified through axial compression resistance tests that the composites prepared with 1.5 % (w/w) had superior compressive strength by around 20% compared to the composites prepared with 2 % (w/w). In other words, with a lower concentration it achieved a satisfactory reinforcement effect, better preserving the structure. From the analysis of the diametral compression resistance results, the concentration of 1.5% (w/w) showed a specific reinforcing effect, both with the use of crushed eggshells and with the use of carbonized rice husks dispersed in concrete. The concentration of 1.5% (w/w) showed a specific reinforcing effect, both with the use of crushed eggshells and with the use of carbonized rice husks dispersed in concrete. The lowest content of 1% (w/w) was not enough to reinforce the material, presenting the lowest yield strength values of 2.98 and 3.54 MPa for egg and rice, respectively. The values for 1.5% (w/w) reached values of 4.22 and 4.68 MPa, for egg and rice. Around 20% of the compounds prepared with the highest filler levels, both with crushed eggshell and carbonized rice husk.

Experimental Study on Mechanical Characteristics of Stabilized Soil with Rice Husk Carbon and Calcium Lignosulfonate

In cold regions, the extensive distribution of silt exhibits limited applicability in engineering under freeze–thaw cycles. To address this issue, this study employed rice husk carbon and calcium lignosulfonate to stabilize silt from cold areas. The mechanical properties of the stabilized silt under freeze–thaw conditions were evaluated through unconfined compressive strength tests and triaxial shear tests. Additionally, scanning electron microscopy was utilized to analyze the mechanisms behind the stabilization. Ultimately, a damage model for rice husk carbon–calcium lignosulfonate stabilized silt was constructed based on the Weibull distribution function and Lemaitre’s principle of equivalent strain. The findings indicate that as the content of rice husk carbon and calcium lignosulfonate increases, the rate of improvement in the compressive strength of the stabilized silt progressively accelerates. With an increase in the number of freeze–thaw cycles, the deviatoric stress of the stabilized soil gradually diminishes; the decline in peak deviatoric stress becomes more gradual, while the reduction in cohesion intensifies. The decrease in the angle of internal friction is relatively minor. Microscopic examinations reveal that as the number of freeze–thaw cycles increases, the soil pores tend to enlarge and multiply. The established damage model for stabilized silt under freeze–thaw cycles and applied loads demonstrates a similar pattern between the experimental and theoretical curves under four different confining pressures, reflecting an initial rapid increase followed by a steady trend. Thus, it is evident that the damage model for stabilized silt under freeze–thaw conditions outperforms traditional constitutive models, offering a more accurate depiction of the experimental variations observed.

INVESTIGATION OF THE EFFECT OF AN IMPREGNATING AGENT ON THE SORPTION CHARACTERISTICS OF A CARBON-SILICON SORBENT

Efforts to control the spread of airborne respiratory pathogens in enclosed public spaces have become particularly relevant due to the COVID-19 pandemic. One of the control methods is the use of bactericidal filters for ventilation air purification systems in enclosed public spaces in order to effectively remove pathogenic microorganisms from the air environment. The impregnated sorbents developed in this work are used as a filter material. The purpose of the work is investigation of the effect of an impregnating agent on the sorption characteristics of a carbon-silicon sorbent used as the basis of bactericidal filters for air purification. Methodology. It has been established that carbonation makes it possible to obtain more durable carbon sorbents with a high specific surface area. According to the results of X-ray dispersion analysis, carbonized rice husk contains 86.57% carbon and 1.75% silicon. Results and discussion. The effect of the carbonization process on the specific surface area and specific volume of the initial sorbent has been studied. The specific surface area was measured and the pore size of impregnated carbon-silicon sorbents was measured. The study of the effect of impregnating agents on the sorption characteristics of a carbon-silicon sorbent showed that an increase in the concentration of chlorhexidine and tannin in the composition leads to an increase in the specific surface area and specific pore volume of sorbents. Conclusion. It was found that the impregnation of a carbon sorbent leads to an increase in the specific surface area from 320 g/m2 to 350 g/m 2, the specific pore volume from 0.1256 cm3/g to 0.1399 cm3/g.

Comparative characteristics of thermal stability of polyethylene in the presence of complex fillers based on natural raw materials

A comparative analysis of the effect of new complex fillers of natural origin on the process of thermal aging of high-pressure polyethylene is carried out. During the research, it was found that the studied fillers have a stabilizing effect, inhibiting the processes of thermal oxidation of high-pressure polyethylene. The stabilizing effect of fillers is due to the presence in their composition of metal oxides capable of chemical interaction with oxygen-containing groups in oxidized polyethylene. It has been established that the carbon-mineral filler has a higher thermostabilizing effect than the carbon-silicon filler from carbonized rice husk.

Enhanced‐Performance Electrodes from Biomass‐Derived Carbon (Rice Husk) for Printable Perovskite Solar Cells

In the quest for sustainable energy solutions, printable carbon‐based perovskite solar cells (p‐MPSCs) are capturing the industry's attention due to their exceptional stability, simplified assembly, and cost‐effectiveness. At the heart of this innovation lies the carbon electrode, favored for its straightforward printing and assembly processes, making it an ideal candidate for renewable photovoltaic applications that leverage biomass carbon. This study casts the spotlight on rice husks, a plentiful yet underutilized resource, repurposing them into carbon electrodes for p‐MPSCs through a specialized carbonization treatment. A comprehensive examination reveals that the integration of 20% rice husk carbon (RHC) with graphite significantly improves the material's filling and crystalline qualities, diminishes the density of defect states, and strengthens the suppression of nonradiative recombination. These advancements culminate in a notable increase in photovoltaic conversion efficiency, reaching up to 11.49%. This study not only demonstrates the viability of RHC in photovoltaic applications but also supports the efficient use of biomass carbon, contributing to the progression of green energy technologies.

Superiority of native soil core microbiomes in supporting plant growth

Native core microbiomes represent a unique opportunity to support food provision and plant-based industries. Yet, these microbiomes are often neglected when developing synthetic communities (SynComs) to support plant health and growth. Here, we study the contribution of native core, native non-core and non-native microorganisms to support plant production. We construct four alternative SynComs based on the excellent growth promoting ability of individual stain and paired non-antagonistic action. One of microbiome based SynCom (SC2) shows a high niche breadth and low average variation degree in-vitro interaction. The promoting-growth effect of SC2 can be transferred to non-sterile environment, attributing to the colonization of native core microorganisms and the improvement of rhizosphere promoting-growth function including nitrogen fixation, IAA production, and dissolved phosphorus. Further, microbial fertilizer based on SC2 and composite carrier (rapeseed cake fertilizer + rice husk carbon) increase the net biomass of plant by 129%. Our results highlight the fundamental importance of native core microorganisms to boost plant production.

A novel biogenic porous core/shell-based shape-stabilized phase change material for building energy saving

The application of phase change materials (PCMs) for thermal storage in construction can effectively reduce building energy consumption. However, high costs and vulnerability to leaks have hindered their application. The present study proposes two approaches for the synthesis of porous supporting matrices derived from rice husk, resulting in the formation of rice husk silica (RHS) and rice husk carbon (RHC). Then, n-octadecane and the porous materials were combined by vacuum impregnation, while the leakage resistance performance of the composite PCMs was enhanced by applying epoxy resin coating to create a shell-core structure. The results show that the n-octadecane/RHS and n-octadecane/RHC composite PCMs exhibit high latent heat potential of 106.5 J/g and 116.3 J/g, respectively. Both porous supporting structures provided the PCMs with robust structural stability and exceptional thermal conductivity. The thermal conductivity of the n-octadecane/RHS composite PCMs and n-octadecane/RHC composite PCMs reached 0.52 W/(m K) and 0.41 W/(m K), respectively. The thermal properties of the biogenic porous core/shell-based shape-stabilized PCMs were characterized by an analog T-history method, and the results demonstrated that the composite PCMs exhibited excellent and rapid heat storage and exothermic capabilities. After undergoing 300 complete heating and cooling cycles, the composite PCMs demonstrate exceptional thermal reliability and possess a high enthalpy capacity. Finally, the impact of the pore structure of RHS and RHC on the crystallization behavior of n-octadecane was discussed. Both composite PCMs can be regarded as environmentally friendly construction materials with promising thermal and acoustic properties.

Enhancing the thermal cyclic reliability of salt-based shape-stabilized phase change materials by in-situ SiO2–C interconnectivity in rice husk carbon

Utilizing salt-based shape-stabilized phase change materials (ss-PCMs) for high-temperature thermal energy storage stands as a pivotal avenue in realizing carbon neutrality. However, the performance of ss-PCMs significantly deteriorates after thermal cycling. This study utilizes rice husk carbon (RHC) with an in-situ SiO2–C interconnected structure as the encapsulating material, along with expanded graphite (EG) and MgO, to encapsulate ternary chloride (TC). In this approach, RHC simultaneously acts as a thermal conductivity materials (TCM) and a ceramic supporting material (CCM). The results showed that this encapsulation method can effectively encapsulate up to 65% of TC. The 60 wt% TC-10 wt% RHC-10 wt% EG-20 wt% MgO sample named 60T/10R/10E/20M is considered a close to optimal formulation in terms of thermal conductivity and phase change enthalpy. This ss-PCM has a thermal conductivity of 8.86 W m−1 K−1, and phase change enthalpy of 153.6 J g−1. The ss-PCMs maintained shape stability even after 1000 cycles, with minimal mass loss and thermal conductivity degradation compared to the non-RHC-added ss-PCM. This study has prepared high performance and reliability thermal storage materials through a green and low-cost approach.

Active carbon derived from rice husk as sustainable substitutes for costly platinum electrodes in dye-sensitized solar cells

Significant financial and environmental challenges are associated with using platinum electrodes as counter electrodes (CEs) in dye-sensitized solar cells (DSCs). This work uses rice husk, an agricultural waste, to create active carbon that is appropriate for DSC CEs in response to these difficulties. A simple spray pyrolysis technique created activated carbon obtained from rice husks. The DSC employing activated rice husk carbon as the CE demonstrated a conversion efficiency of 6.06%, slightly lower than the 8.21% efficiency achieved with a platinum electrode-based cell. However, this performance gap is overshadowed by the substantial cost reduction enabled by the utilization of low-cost activated carbon compared to noble metal alternatives. This result introduces promising avenues for investigating the use of agriculturally derived carbon materials as workable and affordable options for platinum CEs in DSCs, thereby contributing to the sustainable advancement of photovoltaic systems. Even though the performance of DSC that uses activated carbon derived from rice husk in CE is slightly lower than its counterparts based on platinum, the cost reduction due to the use of low-cost activated carbon with noble metal is significant.

Substrates based on carbonized rice husk combined with phosphate fertilization in coriander and mustard seedlings

Combinations of substrates of easy acquisition and nutrients availability favor the production of quality seedlings with lower production cost. Aiming at an alternative for the production of quality seedlings from the insertion of low-cost, sustainable raw material into the commercial substrate, the present work aimed to evaluate the effect of different proportions of the composition of the carbonized rice husk mixture, sand and soil (3:1:3 V:V:V) with commercial substrate (composed of peat fiber and vermiculite), with or without added phosphorus, without development of coriander and mustard seedlings. The experiment was executed in a greenhouse under a randomized block design with six seedlings per plot and seven replications. The treatments were arranged in a 5x2 factorial scheme with 0, 25, 50, 75 and 100 % of the combination added to the commercial substrate with or without addition of triple superphosphate. After 35 days of emergency, plant height, shot dry mass production and roots dry mass production were evaluated. The results showed that there was no effect on the phosphate fertilizer addition to the substrates tested in any evaluated trait, as well as significant interaction between the factors studied in the development of seedlings. The height and dry matter yield of shoots and roots were higher when the combination of carbonized rice husk, sand and soil was added to the commercial substrate in proportions of 50 % and 75 % and 100 % in both vegetables. Carbonized rice husk proved to be an efficient alternative substrate for the production of coriander and mustard seedlings.

Decoration of dandelion-like manganese-doped iron oxide microflowers on plasma-treated biochar for alleviation of heavy metal pollution in water

Carbon-based biowaste incorporated with inorganic oxides as a composite is an enticing option to mitigate heavy metal pollution in water resources due to its more economical and efficient performance. With this in mind, we constructed manganese-doped iron oxide microflowers resembling the dandelion-like structure on the surface of cold plasma-treated carbonized rice husk (MnFe2O3/PCRH). The prepared composite exhibited 45% and 19% higher removal rates for Cu2+ and Cd2+, respectively than the pristine CRH. The MnFe2O3/PCRH composite was characterized using XRD, FTIR, FESEM, EDX, HR-TEM, XPS, BET, TGA, and zeta potential, while the adsorption capacities were investigated as a function of pH, time, and initial concentration in batch trials. As for the kinetics, the pseudo-second-order was the rate-limiting over the pseudo-first-order and Elovich model, demonstrating that the chemisorption process governed the adsorption of Cu2+ and Cd2+. Additionally, the maximum adsorption capacities of the MnFe2O3/PCRH were found to be 122.8 and 102.5 mg/g for Cu2+ and Cd2+, respectively. Based on thorough examinations by FESEM-EDS, FTIR, and XPS, the possible mechanisms for the adsorption can be ascribed to surface complexation by oxygen-containing groups, a dissolution-precipitation of the ions with –OH groups, electrostatic attraction between metal ions and the adsorbent's partially charged surface, coordination of Cu2+ and Cd2+ with π electrons by aromatic/graphitic carbon in the MnFe2O3/PCRH, and pore filling and diffusion. Lastly, the adsorption efficiencies were maintained at about 70% of its initial adsorption even after five adsorption-desorption cycles, displaying its remarkable stability and reusability.

BiOBr-rice husk carbon composite for antibiotic degradation

Highly efficient visible light photocatalysts are necessary to address the water pollution caused by antibiotics. In the present study, bismuth oxybromide-rice husk-derived carbon (BiOBr-RHC) composites (with different wt% of RHC) were prepared via a simple solid-state method. Results of the studies indicate that the use of rice husk carbon has a considerable effect on the degradation of the commonly used fluoroquinolone antibiotic norfloxacin (NOR). BiOBr-RHC-10 exhibits the highest catalytic degradation towards NOR under visible light irradiation among the developed composite catalysts. Introducing carbon in the composites provides better separation of charge carriers, thereby reducing the recombination rate of electron-hole pairs. The promising visible-light-driven catalytic activity of the BiOBr-RHC composite makes it a potential candidate for the effective degradation of the antibiotic present in wastewater.

Production of strawberry cultivars in a closed system of growing on substrate with transplants of different origins

The growing of strawberries in substrate has grown because it is a profitable way of production, easy to work, and which reduces the occurrence of diseases. Like closed growing systems they have a low environmental impact. The imported strawberry transplants bare root are considered more productive, however they arrive late in Brazil, shortening their production cycle, so transplants produced under local conditions would be an alternative to increase producers' income. Thus, the objective of this work was to evaluate the productive result of strawberry transplants produced under local conditions and imported bare root, growing in a closed growing system soilless, on a carbonized rice husk substrate and with the addition of organic compost. Three experimental factors were evaluated: 1st) substrate: carbonized rice husk (CRH) and CRH with 20% organic compound (OC) (CRH + OC); 2nd) cultivars: ‘Camarosa’ and ‘San Andreas’; and 3rd) transplants origin: bare root imported, and runners plants produced under local conditions. The local runner's plants outperformed imported bare root in relation to the number of fruits, however, the imported bare root provided greater average fresh weight of fruits. The runner’s plants of the cultivar 'San Andreas' produced 732.9 g plant-1, higher than the production of imported bare root, with 44.9% of the harvest harvested in the months of July and August. The 'Camarosa' cultivar didn't show the difference in yield between local and imported transplants. Transplants of cv. 'San Andreas' shallow rooted directly into the slabs under local natural conditions can guarantee earlier harvest, greater production, and higher fruit yield. As for the substrate, plant growth and commercial productivity were not influenced by the addition of OC to CRH. The results indicate that the addition of OC to the CRH has no influence on plant growth and commercial fruit production.

Seed biometry, growth, and seedling development of Adenium obesum (Forssk.) Roem. & Schult. in substrates

The desert rose (Adenium obesum (Forssk.) Roem. & Schult.) is a plant that has been widely used for garden ornamentation, holding significant importance in the landscaping and gardening market. Thus, establishing a way to perform biometric analysis and a seedling production system that offers significant utilization of water and available materials for substrate composition in each region is crucial for propagation and the quality of these plants. The objective of this study was to evaluate biometric aspects and investigate the influence of different substrates on the physiological potential of seeds and the initial growth of desert rose seedlings. This study was conducted at the Vitrine do Verde plant store located on Rodovia Dr. Ib Gatto Marinho Falcão, AL 101 south - Barra Nova, Marechal Deodoro – AL (9°43'31.2"S 35°49'46.6"W), with A. obesum seedlings produced from seeds. This study identified crucial points for seedling growth and development, providing information that allowed optimizing the production system with reduced costs. It was observed that among the substrates used, the use of treatment T3 composed of decomposed rice husk (55%) + carbonized rice husk (15%) + topsoil (15%) + peanut shell (15%) is preferable, as it proved to be efficient in the analyzed parameters. However, it is worth noting that further studies are necessary to increase knowledge and facilitate the cultivation of this highly appreciated crop.

Experimental research on optimizing carbon materials for filtration applications in medicine

In the present investigation, carbonized rice husk (CRH) were used as a feedstock for obtaining experimental samples of a carbon monolith. The choice of carbonized rice husk is due to environmental friendliness and availability, optimal physico-chemical and structural features. CRH was obtained by carbonization of rice husks in steam at 900–950 °C, followed by demineralization of 2–15 % nitric acid. The article is devoted to the study of carbon material for use in medicine. In this work, 9 samples of a carbon monolith with different ratios of components were obtained. The samples were obtained on the basis of CRH and plastic mass, which were used as binders. A sample with optimal characteristics was determined: sorption capacity 75.6 %, specific surface according to the multi-current BET method 360.56 m2, sorption of ethyl alcohol in biological media 50 %. Sorption capacity was determined using methylene blue dye, which simulates medium molecular weight toxicants. The specific surface area was measured on a sorbtometer using the multiprecision BET method, and the sorption of ethyl alcohol in biological media was determined on a chromatograph. It has been established that the carbon-silicon composition of the sorbent has the mildest sorption compared to the pure carbon composition. Sample No. 8 has a high specific surface area and sorption capacity, which will allow it to absorb a wide range of toxins of various origins, including biological fluids

Hydrothermal Carbonization and Torrefaction of Kenaf, Rice Husk, Corncob, and Wood Chip: Characteristics and Differences of Hydrochar and Torrefied Char

Hydrothermal Carbonization and Torrefaction of Kenaf, Rice Husk, Corncob, and Wood Chip: Characteristics and Differences of Hydrochar and Torrefied Char

Yield, lodging, and water use efficiency of Tef [Eragrostis tef (zucc) Trotter] in response to carbonized rice husk application under variable moisture condition.

Terminal drought and lodging are among the major yield-limiting factors for tef cultivation in the highly weathered soils of the Ethiopian highlands. Therefore, a study was conducted to assess the yield and lodging responses of tef to varying moisture depletion levels (MDL) and the application of carbonized rice husk (CRH). A two-year 4×4 factorial experiment with 20, 35, 55, and 75% MDL and 0, 291, 582, and 873 kg ha-1 of CRH was laid out in a split-plot design, with each treatment replicated four times. The pooled mean ANOVA showed leaf area index (LAI) and lodging index (LI) were not significantly influenced by the main and interaction effects of MDL and CRH (p > 0.05); however, individual year ANOVA showed that both LI and LAI were influenced by the interaction of MDL and CRH (p<0.05) in 2021 and 2022, respectively. The lowest LI (19.7%) was obtained from the application of 873 kg CRH ha-1, followed by 20.6% from 582 kg CRH ha-1 in 2022. A 20.7% LI reduction was recorded in 2022 compared to 2021. Tef plant height and number of tillers per plant were significantly affected by MDL at p<0.05 and p<0.01, respectively, but not by CRH and its interaction with MDL. The effect of MDL was significant on tef HI (p<0.01) but not on traits including grain yield, straw yield, and water use efficiency. In conclusion, the pooled mean analysis result showed that, though there was no significant difference in yield, tef irrigated at 55% MDL provided a maximum HI of 33.8%, which was 6.21% more than the control, and increased the level of lodging resistance with a LI of 31.9%, which was next to 75% MDL with 582 kg ha-1 CRH. The authors suggested that the research should further be verified across locations for wide application.

Novel Fe3O4–ZnO Carbonized Rice Husk Modified Nano Composite Sorbent for Removal of Humic Acid from Aqueous Media

Novel Fe3O4–ZnO Carbonized Rice Husk Modified Nano Composite Sorbent for Removal of Humic Acid from Aqueous Media

Carbonization of rice husk for adsorption of phosphate compounds: Influence of temperature and NaOH activator

Rice husk is mostly composed of cellulose, hemicellulose, and lignin that can be converted into carbon to be used as an adsorbent. Phosphate is one of the elements that cause eutrophication, resulting in algae blooming. The purpose of this research is to determine the best carbonization temperature and concentration of NaOH activator. The phosphate compounds studied are Sodium Tripolyphosphate (STPP) as artificial phosphate compounds and phosphate compounds in laundry wastewater. Carbonization of rice husk was done for 1 hour with temperature varied at 400, 425 and 450°C. The carbon activation of rice husk was done for 24 hours with variation of NaOH concentrations of 0.3, 0.5, and 0.7 M. The performance test of 100 mesh activated carbon was performed at a speed of 100 rpm and stirring time of 45 minutes. Activated carbon with the best characteristics was obtained from a carbonization temperature of 450°C and activated by 0.3 M NaOH. The characteristics obtained were 1.90%, 35.82%, 20.04%, 42.25%, 49.4 mg/g for water content, ash content, volatile matters, fixed carbon, methylene blue adsorption, respectively. The best dose was 16 g/L of active carbon with an adsorption efficiency of 75.15% on STPP and 93.7% on laundry wastewater.

Synthesis of X@DRHC (X=Co, Ni, Mn) catalyst from comprehensive utilization of waste rice husk and spent lithium-ion batteries for efficient peroxymonosulfate (PMS) activation

Highly efficient resource recycling and comprehensive utilization play a crucial role in achieving the goal of reducing resource wasting, environmental protection, and achieving goal of sustainable development. In this work, the two kinds waste resources of agricultural rice husk and metal ions (Co, Ni, and Mn) from spent lithium-ion batteries have been skillfully utilized to synthesize novel Fenton-like catalysts. Desiliconized rice husk carbon (DRHC) with rich pore structure and large specific surface area from rice husk has been prepared and used as scalable carrier, and dandelion-like nanoparticles cluster could be grown in situ on the surface of the carrier by using metal ions contained waste water. The designed catalysts (X@DRHC) as well as their preparation process were characterized in detail by SEM, TEM, BET, XRD and XPS, respectively. Meanwhile, their catalytic abilities were also studied by activating potassium peroxomonosulfate (PMS) to remove methylene blue (MB). The results indicate X@DRHC displays excellent degradation efficiency on MB with wide pH range and stable reusability, which is suitable for the degradation of various dyes. This work has realized the recycling and high-value utilization of waste resources from biomass and spent lithium-ion batteries, which not only creates an efficient way to dispose waste resources, but also shows high economic benefits in large-scale water treatment.