Cellulose Content Research Articles

Energy harvesting through the triboelectric nanogenerator (TENG) based on polyurethane/cellulose nanocrystal

This study investigates how physical and mechanical properties affect the performance of triboelectric nanogenerators (TENGs). Polyurethane (PU) was prepared using two methods: (i) one-step PU (non-chain extended polyurethane) and (ii) two-step PU (chain extended polyurethane) via the prepolymer method; both types were filled with different concentrations of nanocrystalline cellulose. Mechanical properties significantly influence the deformation at the material interface that occurs during contact or friction. Key surface characteristics, including surface energy, geometry, and physicochemical properties, affect the effective contact area and potential distribution. One-step PU with 0.1 % CNC demonstrates a maximum capacitance of 29.20 pF, a voltage of 2.04 V, an electric current of 0.43 µA and power of 0.89 µW, representing a 74.5 % increase in power compared to the neat one-step PU, exhibits significant potential for TENG applications. Performance improvements are associated with lower concentrations of cellulose nanocrystals, enhanced hydrogen bonding, and beneficial surface energy. The observed enhancements in output are attributed to improved internal polarization from well-dispersed crystalline nanocellulose, increased crystallinity of the soft segment, and reduced charge transfer mechanisms due to amino groups in the chain extender. However, the impact of the molecular structure and conformation of polyurethanes on triboelectrification remains unclear, highlighting the need for theoretical models and experimental data. This research provides a practical approach for developing stretchable triboelectric materials with enhanced mechanical properties, emphasizing the importance of considering factors such as mechanical parameters, nanofiller content, and surface physicochemical properties to optimize TENG design.

Microorganisms of solid waste as an opportunity for waste disposal and increasing environmental sustainability in the south of Kazakhstan

The study is devoted to the problem of processing the organic waste that is generated as a result of paper, textiles and other industries production as well as food waste. The growth of economic activity in Kazakhstan has resulted in a significant challenge with regard to industrial waste management. The accumulation of waste on the territory of the country has reached 31.72 billion tonnes, comprising approximately 2.5 billion tonnes of hazardous waste, 50 million tonnes of phosphorus-containing waste, over 2.5 million tonnes of lead-zinc waste and more than 120 million tonnes of solid domestic waste. The study object was the Shymkent-Kokys polygons. According to the research carried out, it was determined that the titer of microorganisms of the studied groups is 1–10 CFU/g in the soils selected around the garbage in the area of the Shymkent landfill. The titer of microorganisms in the soil horizons was high at a depth of 20–30 cm and the titer were 109 cells/mL. The structure of the soil microbiome obtained around the Shymkent Waste Landfill consists of actinomycetes, micromycetes, heterotrophic bacteria, nitrifying, nitrogen-fixing bacteria, enterobacteria, as well as algae and protozoa. It was found that strains KPA1, KPA2 Pseudomonas sp. strains KPA3, KPA4, KPA5 Bacillus sp. isolated from the soils of the Shymkent-Kokys landfill are able to recycle domestic waste with a high content of cellulose and organic substances up to 95%–97%. The findings can be used to develop more effective organic cellulosic waste management strategies and improve the environmental sustainability of various industries.

Evaluation of Organic Waste Long-Term Effects on Cellulose, Hemicellulose and Lignin Content in Energy Grass Species Grown in East-Central Poland

Biomass can be used for electricity generation, especially in developing countries, but also in developed ones, where the utilization of renewable energy sources is being integrated into a sustainable economy. There are considerable differences in the scale of biomass use and in the technology of its processing. One of the most important sources of biofuel is the biomass of grass. This research aimed to determine the long-term effects of organic fertilizers on cellulose, hemicellulose, and lignin content in the biomass of three grass species: giant miscanthus (Miscanthus × giganteus), prairie cordgrass (Spartina pectinata), and switchgrass (Panicum virgatum L.) in the first three years of growth. The experiment was established in four replications on microplots of 2 m2 in April 2018. Before planting grass rhizomes, municipal sewage sludge (SS) and spent mushroom substrate (SMS) were introduced into the soil in various combinations. Biomass is harvested in December every year. The content of structural polysaccharides in the grass species statistically significantly varied in response to organic waste. Compared to other fertilizer combinations, SS application increased the content of cellulose in the biomass of Miscanthus giganteus (43.66% of DM) and Spartina pectinata (37.69% of DM) and hemicellulose in Spartina pectinata (27.80% of DM) and Panicum virgatum (23.64% of DM). Of the three species of grass, the chemical composition of Miscanthus giganteus cell walls was the most favorable for biofuel production, with the most cellulose and hemicellulose and the least lignin compared to other grass species. The content of lignin in the biomass of Miscanthus × giganteus and Spartina pectinata was the greatest on the plot with SMS and amounted to 7.79% of DM and 12.32% of DM, respectively. In the case of Panicum virgatum, the average content of lignin was similar across all fertilized plots, with 15.42% DM.

Characterization of the Physicochemical Properties of Salix psammophila Sand Barriers Degradation Under Ultraviolet Irradiation and Synergistic Water Environment

The degradation of Salix psammophila mechanical sand barriers in desert environments can lead to a reduction in their windbreak and sand-fixing benefits, thereby becoming a significant factor limiting the operational lifespan of these structures. Targeting the typical damage types of S. psammophila sand barriers in the desert, we conducted simulations of desert sunlight and rainfall phenomena and investigated the changing characteristics of the physical, mechanical, and chemical properties of sand barriers in the degradation process. The results clearly indicate that (1) accelerated aging for 288 h represents a critical time point for assessing changes in physical, mechanical, and chemical properties during the interaction between ultraviolet irradiation and water. Following 576 h of accelerated aging, compared with a fresh S. psammophila branch sample (CK), the mass loss percentage was 24.33%, while the basic density decreased by 35.87%, and the modulus of rupture and elasticity decreases by 24.93% and 23.03%, respectively. (2) After accelerated aging for 576 h, the contents of lignin, hemicellulose, and cellulose decreased by 35.93%, 33.84%, and 22.38%, respectively. The interaction between simulated ultraviolet irradiation and water under sunlight intensifies the vigorous physical and chemical reactions occurring within the S. psammophila sand barrier, alters its internal structure, diminishes its mechanical properties, and expedites the degradation of its protective capabilities.

Extraction and characterization of bark fibers from Ethiopian Ficus thonningii tree

The growing environmental pollution issues by synthetic textile products demand sustainable natural textile alternatives. This paper aimed at extracting and characterizing a new fiber called Ficus thonningii fiber from Ficus thonningii trees found in Ethiopia to be used as a source of textile fiber for different applications. The study utilized water and chemical extraction with sodium hydroxide methods. Physical, mechanical, and chemical properties such as length, diameter, fineness, tenacity, moisture content, moisture regain, cellulose, hemicellulose, lignin, and ash content were characterized. The results revealed that Ficus thonningii fiber possesses comparable characteristics with jute, sisal, and flax fibers that can be used for different applications. The fiber exhibits tenacity of 39.65 cN, an elongation of 2.60%, a moisture content of 10.78%, and a moisture regain of 11.98% when extracted chemically. While it exhibits a tenacity of 37.83 cN, an elongation of 3.02%, a moisture content of 10.35%, and a moisture regain of 11.02% when extracted using water extraction method. Both extraction methods yield a fiber length of 101.50 mm. The chemical composition of the fiber obtained through water extraction consists of 52.35% cellulose, 19.20% hemicellulose, 17.20% lignin, and 1.20% ash. On the other hand, the chemical extraction method results in a composition of 63.57% cellulose, 16.10% hemicellulose, 12.10% lignin, and 0.83% ash. These results confirm the potential use of Ficus thonningii tree as a valuable source of coarse fibers for various technical textile applications.

Simple model to predict the intrinsic flexural modulus of abaca strands from crystallinity and microfibril angle

AbstractThis study presents a novel equation that obtains the intrinsic flexural modulus of a natural fiber from its microfibril angle (MFA) and its crystalline cellulose content, once having estimated both parameters from X‐ray diffraction (XRD). The percentage of crystalline cellulose was estimated as the content of cellulose times the crystallinity index. Moreover, the MFA of abaca strands was obtained through an equation relating MFA with the strain at break of the strands and by XRD azimuthal integration, obtaining similar results. Fully bio‐based composites, consisting of biopolyethylene reinforced with of abaca strands at 20 to 50 wt% contents, were tested to assess the impact of the natural fibers on the flexural modulus of the composites. The intrinsic flexural modulus was also evaluated by using three micromechanics models (Hirsh equation, Halpin and Tsai equation, and its modification by Nielsen). The values obtained from the application of the new equation, the micromechanics methods, and the literature showed satisfactory agreement.Highlights Evaluation of the flexural modulus of abaca strand reinforced bio‐polyethylene composites. Use of micromechanics models to obtain the intrinsic modulus of abaca strands. Formula that correlates the intrinsic flexural modulus of abaca to its crystalline cellulose content and microfibril angle.

Tailored Interaction between Cellulose Nanowhiskers and Core-Shell Particles Determines the Optical and Mechanical Properties in Hybrid Films.

Hybrid materials of core-shell particles and cellulose nanowhiskers (CNWs) were synthesized to produce opal films with increasing tensile strength. After the incorporation of CNWs into the processed particle films, differences in the mechanical and optical properties were noticeable, which stemmed from the adhesion forces between the cellulose and the particles' shell material. Two different particle compositions were compared, using polystyrene as cores, and either poly(ethyl acrylate) (PEA) or a copolymer of ethyl acrylate and 3 wt % of 2-hydroxyethyl methacrylate (HEMA) as the shell material. Stronger interactions between the particles containing HEMA and the CNWs were displayed via atomic force microscopy particle manipulation experiments, where higher forces were required to deliberately move P(EA-co-HEMA) particles on a CNW substrate compared to PEA particles. The stronger interaction behaviors increased the disorder of the particles within the opal films toward photonic glasses with angle-independent structural colors. Also, the increase in tensile strength from <1 MPa at a cellulose content of 0 wt % to 6 MPa at the optimal CNW content of 15 wt % was more pronounced compared to the particle-cellulose mixture with only PEA in the particle shell. Thus, the presence of the hydroxy groups in the particles' shell material on the molecular level significantly influenced the optical and mechanical properties on the macroscopic level.

Effect of pretreatment and peracetic acid pulping on cellulosic materials converted from spent coffee grounds.

Spent coffee grounds (SCG) are the waste byproducts of coffee brewing. While SCG can be valorized to produce functional biopolymers due to their valuable structural components, the lignocellulosic structure of SCG is resistant to degradation because of the tightly bound lignin. Therefore, a pretreatment step is required before pulping with peracetic acid (PAA), an eco-friendlier alternative to traditional pulping methods, to facilitate the extraction of these desired cellulosic materials. Formic acid:acetic acid:deionized water (FA:AA:W=30:50:20) or 60% (v/v) ethanol pretreatments were applied to SCG to compare the characteristics of the resulting cellulosic materials after PAA pulping. Lignocellulose analysis showed that the lignin content (7.06%) of ethanol pretreated SCG was significantly lower (p<0.05), and the cellulose content (29.52%) was significantly higher (p<0.05) than the untreated SCG (15.50% and 11.50%, respectively), indicating that an adequate amount of lignin was removed to obtain the cellulosic materials after the pretreatment process. Morphological and structural changes in the lignin and hemicellulose were observed in all the pretreated SCG, which further confirmed that these components were degraded with pretreatments and pulping. Ethanol pretreated SCG showed the most optimal results based on the greatest lignin decrease seen from its lignocellulose composition, appearance, and structure. This study exemplified a conversion process to extract cellulosic materials from SCG more efficiently to utilize for cellulose-based products and verify its potential to be valorized as a waste byproduct. PRACTICAL APPLICATION: Coffee companies can provide the spent coffee grounds (SCG) they produce to develop cellulose-based materials to make biodegradable packaging products rather than throwing them out or burning them. Using SCG for producing cellulose-based materials can help promote sustainability and reduce food waste worldwide. SCG can be utilized as an alternative source based on their abundance and desired biopolymeric properties, providing innovative solutions to industries and increasing consumer awareness of this cause.

Enhanced Thermal and Flexural Properties of Alkalized Date Palm/Kenaf Fiber-Reinforced Epoxy Hybrid Composites: A Comparative Study of Untreated and Treated Fibers

ABSTRACT This study evaluates the thermal and mechanical behavior of hybrid composites made from date palm (DP) and kenaf fibers (KF) in an epoxy thermoset matrix. Both DP and KF fibers are abundant and renewable, reducing environmental impact. KF offers high tensile strength and stiffness, improving composite strength and rigidity, while DP fibers offer toughness and impact resistance, enhancing durability. The composites were developed in 30%, 50%, and 70% DP-KF compositions using layup and hot-pressing methods. Fiber treatment through alkalization was analyzed for its impact on mechanical and thermal properties to find the optimal fiber ratio. The hybrid composites were subjected to DMA, TGA, and flexural tests. The treated composites exhibited fewer impurities and increased cellulose content, resulting in enhanced flexural performance. This improvement was evident through higher storage modulus, lower loss modulus, and reduced tan δ when exposed to thermal stress. The 30% DP and 70% KF composites exhibited best performance. The treated 30DP-70KF exhibited improvement in the flexural strength and modulus by 13.8% and 2.7%, respectively. TGA demonstrated that treated 30DP-70KF composites had a higher glass transition temperature (Tg) and better thermal degradation resistance. These findings highlight the potential of natural fiber hybrids in creating sustainable, high-performance composite materials for construction and industrial applications.

Postharvest melatonin application attenuates browning, delays softening, and maintains the antioxidant potential of jackfruit bulbs

Although the impact of postharvest melatonin (MLT) application in extending the storage life of horticultural produce has been widely studied, its effect in jackfruit remains unknown. This investigation evaluates the influence of MLT dip application (0, 0.05, 0.1, and 0.2 mM) on browning, softening and oxidative stress in cold-stored jackfruit bulbs over a period of 20d. All MLT treatments reduced browning index and oxidative stress, while activities of browning-related enzymes were comparatively lower in the 0.1 mM MLT treatment. Treatment with 0.2 mM MLT maintained elevated levels of antioxidants as compared to control. Higher bulb firmness, total pectin and cellulose content with considerably lower activities of cell wall degrading enzymes were observed in all MLT treatments. In conclusion, MLT (0.1 and 0.2 mM) is an effective treatment for mitigating postharvest browning and oxidative stress in addition to delaying fruit softening and maintaining the antioxidant potential of cold-stored jackfruit bulbs.

The biological mechanism of a lower carbon/nitrogen ratio increases methane emissions during vegetable waste composting

The initial carbon/nitrogen (C/N) ratio is one of the most important factors impacting composting processes, such as methane (CH4) emissions. However, the effects of the C/N ratio on CH4 emissions and the associated biological mechanisms during vegetable waste composting are largely unknown. In this study, a lab-scale experiment was conducted to investigate the effects of different C/N ratios on CH4 emissions and the mechanisms associated with methane-metabolizing microorganisms (methanogens and methanotrophs) during capsicum straw composting. The initial C/N ratios were set to 18, 30 and 50 to simulate the low (L), medium (M) and high (H) C/N ratios, respectively. The results showed that CH4 emissions were mainly concentrated in the thermophilic phase and that the cumulative CH4 emissions were significantly greater in the L treatment than in the M and H treatments by 10.8 and 15.4 times, respectively. During the methanogenic process, the relative abundance of the dominant genus Methanoculleus (47.59 % ∼ 76.92 %) was higher than in the L treatment than in the M and H treatments at the thermophilic and maturation stages, and the Chao1 index and the mcrA gene abundance followed the order of L > M > H at each composting stage. During the methanotrophic process, the dominant genus unclassified_d_bacteria (51.3 % ∼ 91.87 %), Chao1 index, pmoA gene abundance and CO2 emissions were in the order of L > M > H at each composting stage. This pattern suggests that a lower C/N ratio simultaneously enhanced CH4 production and oxidation. A structural equation model further revealed that the methanogenic community, which was driven directly by the relative contents of hemicellulose and cellulose in the substrates, as indicated by the C/N ratio, made greater contributions to CH4 emissions than did the methanotrophic community. In conclusion, a lower C/N ratio increased CH4 emissions mainly by regulating the population and composition of methanogen community.

Genome-wide identification and expression analysis of SpUGE gene family and heterologous expression-mediated Arabidopsis thaliana tolerance to Cd stress

The UDP-glucose 4-epimerase (UGE) enzyme plays a critical role in plant growth and responses to abiotic stressors, such as heavy metal exposure. However, UGE-mediated remodeling of cell wall polysaccharides in response to these stressors remains poorly understood in willow. This study investigated the structure, function, and expression patterns of the UGE gene family in willow, focusing on cadmium treatment to elucidate how SpUGE1 enhances Cd resistance. Six SpUGE genes were identified through whole-genome sequencing and bioinformatics analysis, and they were mapped across five chromosomes. Quantitative PCR analysis revealed that, with the exception of SpUGE3, all genes showed their highest relative expression in the leaves. Under Cd treatment, members of the SpUGE gene family displayed varying levels of responsiveness, with SpUGE1 showing a marked increase in expression over time. In transgenic Arabidopsis thaliana overexpressing SpUGE1, the cellulose, hemicellulose, lignin, and pectin content significantly increased, with cellulose levels rising by >50 % and pectin by approximately 30 %. This overexpression conferred enhanced Cd resistance by increasing cell wall thickness through elevated cell wall polysaccharides, which reduced Cd uptake. Consequently, Cd content in the cell wall, chloroplasts, and mitochondria was significantly lower than that in wild-type plants, reducing cellular damage and improving Cd resistance. Overall, this study provides valuable theoretical and experimental insights into the role of the SpUGE1 gene family in willow.

Improved Hydrothermal Conversion of Pea Pod Biomass for Production of Platform Chemicals with Organic Acid Catalysts

Agro-industries produce over 2 billion tons of agricultural waste annually, including by-products like bagasse, molasses, seeds, stems, leaves, straw, and shells. The use of agro-industrial waste is a way to reduce the impact of industrial processes on the environment. The pea pod is a biomass with a high concentration of cellulose, hemicellulose and some lignin; therefore, it can be used to produce platform chemicals by means of a hydrothermal process. There is limited research on the hydrolysis of pea biomass, but it has been shown to obtain high yields. This study analyzed the effectiveness and selectivity of the hydrothermal process using pea pod biomass with a particle size of 0.5 mm at 180 °C for one hour. A 500 mL reactor was used, with a biomass-to-acid solution ratio of 1:20. The concentration of the acid solution was 0.02 M. The concentrations of sugar, formic acid, levulinic acid, HMF, and furfural produced were measured. Among the catalysts studied, adipic acid catalysis showed the highest yield of 65.16%, with 37.09% of sugar, 16.37% of formic acid, and 11.71% of levulinic acid. On the other hand, the catalysts with chloroacetic acid, butyric acid, anthranilic acid, and phthalic acid were less effective but demonstrated selectivity for sugar production, proving that the liquid phase obtained using the catalyst with those acids can be used as carbon sources for a fermentation process. In general, when comparing the process with or without the use of a catalyst, it is observed that with a catalyst in the reaction, the amount of HMF and furfural produced is reduced and the selectivity with respect to sugar production is increased.

Immobilization of urea on beads based on OPEFB cellulose-alginate via blending to fabricate sustained release fertilizer

Transforming oil palm empty fruit bunches (OPEFB) waste into value-added cellulose as a reinforcement agent for eco-friendly slow-release fertilizer (SRF) composites is a strategy to achieve clean and sustainable production. OPEFB cellulose was isolated by alkalization (10 % w/v NaOH) for 1 h and bleaching (30 % v/v H2O2) for 1.5 h. The treatment increased the cellulose content to 80.88 %, reduced the non-cellulosic component, and improved the fiber crystallinity to 58.40 %. The hydrogel composite was cross-linked by blending urea in an OPEFB cellulose fiber (w/w) (0 %, 0.5 %, and 1 %) and sodium alginate (3 % w/w). Then, the wet beads were freeze-dried to fabricate SRF composites. Each material was evenly dispersed in the matrix, had a porous structure, and could bind total nitrogen up to 20.0 %, confirmed by the Kjeldahl method. Adding cellulose increased crystallinity (significant at 1 % w/w cellulose), decreased bulky density (significant at 0.5 % and 1 % w/w cellulose), increased swelling capacity (significant at 0.5 % w/w cellulose), and water-retention capacity. Reinforced composite with 0.5 % (w/w) cellulose released nitrogen into the soil (Fickian diffusion) following the Higuchi model (R2 = 0.957) with K = 0.0394 and equilibrium at around t1/2 = 1.8 h. Changing SRF composite properties are likely related to the porous structure loaded with urea crystals.

Unveiling the untapped potential of Hibiscus Rosa-sinensis lignocellulosic fiber: A multifaceted characterization for advancing sustainable biocomposite applications

In the pursuit of sustainable advancements in bio-inspired fiber reinforced polymer composite materials, the exploration of novel natural fibers has become a focal point of research. This experimental study aims to elucidate the unexplored potential of Hibiscus Rosa-sinensis fiber (HRF) as a versatile reinforcement material for high-performance composites. Through an integrated approach, this research offers a meticulous analysis of the HRF's physico-chemical properties, and single fiber tensile strength. The crystalline structure are revealed by X-ray diffraction (XRD), thermal behavior are characterized through thermo-gravimetric analysis (TGA), and surface morphology has been visualized using field emission scanning electron microscopy (FESEM) studies. From the results, it is found that the HRF contains a cellulose content of 79.50 %, positioning it as a prime bast fiber among its counterparts. This composition is complemented by hemicellulose (10.36 %), lignin (4.62 %), wax (0.84 %), and ash (2.96 %). The Fourier-transform infrared spectroscopy (FTIR) spectra unveils the intricate functional groups present in the fibers. XRD analysis highlights a crystallinity index (CI) of 66.93 %, confirming a well-organized and structured crystalline arrangement. The thermal stability established through TGA underscores HRF's resilience up to 284 °C, presenting it is an optimal reinforcement material for bio-inspired green composites operating within 280 °C. The surface morphology of HRF is examined through FESEM and three-dimensional profiling, showcasing its inherent morphological intricacies. The multidimensional characterization provided herein contributes significantly to the evolving landscape of biocomposite research, fostering a platform for future advancements and innovations in HRF-based composite materials.

Identify the key factors driving the lignocellulose degradation of litter along a forest succession chronosequence from the perspective of functional genes

The purpose of this paper was to discover the key factors driving the lignocellulose degradation in litter along a forest succession chronosequence from the perspective of functional genes. We investigated four natural successive stages of forests (white birch forest, broad-leaved mixed forest, coniferous-broad-leaved mixed forest, and mixed broadleaved-Korean pine forest). We determined the lignocellulose degradation of litter and the absolute abundance of related functional genes by using high-throughput-qPCR. There was strong degradation of cellulose content, hemicellulose, and lignin contents in the litter decomposition layer in the early and late stages of forest succession, respectively. Furthermore, forest succession changed microbial communities' succession and fungal Shannon diversity, and then enhanced the absolute abundance of lignocellulose-degrading genes and nitrogen-cycling genes. By network analysis, bacterial and fungal module 1 were key modules for producing lignocellulose-degrading genes and nitrogen cycling genes, while fungal module 2 was a key module for lignin-degrading genes. Fungi were strongly correlated with functional genes based on Procrustes analysis. Additionally, cellulose-degrading genes were the key factor driving the cellulose degradation in the early period of forest succession, while fungal diversity and composition were key drivers in promoting the degradation of lignin in the late period of forest succession. Our study provided insight into the mechanisms underlying the soil microbe-driven functional changes in nutrient cycling and an understanding of the decomposition kinetics of litter at a more microscopic level in the process of forest succession.

Fungal and enzymatic pretreatments of bamboo lignocellulose towards high-strength biocomposites: Biological macromolecule/enzyme interaction and bonding enhancement

An energy-intensive and chemical-consuming pretreatment of bamboo is often required to develop its high-performance composites. This study is to evaluate a fungal and enzymatic pretreatment as a sustainable surface modification approach towards high-strength bamboo biocomposites based on D. sinicus. Extracellular enzyme activity analysis suggested that the lignin oxidative enzyme and pectinase secreted by the white-rot fungus T. versicolor achieved higher reaction than the hydrolytic enzymes throughout the pretreatment. Chemical structure analysis revealed that lignin and hemicellulose were partially depolymerised and/or removed during the pretreatment, leading to a relatively higher cellulose content in D. sinicus. The analysis of physical property and microstructure suggested that the surface wettability and porosity of pretreated D. sinicus were significantly improved, facilitating the spreading and penetration of adhesive resins, which subsequently contributed to the superior interfacial bonding of the biocomposites. The tensile strength of the biocomposites increased from 195.8 MPa to 245.8 MPa and the bonding strength increased from 4.9 MPa to 6.3 MPa after the pretreatment, which were 1.26 times and 1.28 times those of the untreated biocomposite respectively. The results proved that the fungal and enzymatic pretreatment is a promising, eco-friendly and efficient surface modification approach for the preparation of high-strength lignocellulosic biocomposites.

Thermogravimetric Assessment of Biomass: Unravelling Kinetic, Chemical Composition and Combustion Profiles

Thermogravimetric analysis (TGA) was performed on six samples of pine wood, poplar sawdust and olive residue, and the kinetic parameters were evaluated by using isoconversional models. The hemicellulose, cellulose and lignin contents were also estimated using the Fraser–Suzuki deconvolution method. In addition, a range of thermodynamic parameters and combustion indices was calculated. Significant correlations were found between the kinetic, thermodynamic and combustion parameters. The ignition index showed an inverse relationship with the activation energy, whereas the burnout index correlated with enthalpy values for most samples. Higher heating rates during TGA increased ignition and combustion efficiencies but decreased combustion stability. Differences in behaviour were detected between the olive residues, which had a much higher lignin content (51.2–56.9%), and the woody biomass samples (24.2–29.2%). Moreover, the sample with the highest ash content also exhibited some distinctive characteristics, including the lowest high heating value and ignition index, coupled with the highest activation energy, indicating a less favourable combustion behaviour than the other samples. The particle size of the samples was also found to be critical for both combustion efficiency and safety.

Biochar derived from straw residue prepared via combined pre-treatment designed for efficient removal of tetracycline hydrochloride and sulfadiazine sodium salt

In this study, straw residue (SR) was prepared from corn straw by a combined pre-treatment method that involved both microbial treatment (Myrothecium verrucaria, Aspergillus niger, and Trichoderma reesei) and treatment with ρ-toluenesulfonic acid. After pre-treatment, the cellulose content of the residues reached 79.3 %, 72.1 %, 83.5 %, and 85.2 %, respectively. The results indicated that Aspergillus niger and Trichoderma reesei effectively destroyed the corn stover structure, improving the efficiency of the subsequent treatment. Following carbonation and activation processes, the SRs were converted into a series of biochars (ACCC, ACMC, ACTC, and ACNC) with large specific surface areas (2343, 2219, 2693, 2672 m2 g−1). The prepared biochars demonstrated excellent performance in adsorption tests performed using tetracycline hydrochloride (TC) and sulfadiazine sodium salt (SDZ) as adsorption models. The maximum adsorption capacities recorded for TC (908, 1117, 1216, and 1189 mg/g) and SDZ (930, 965, 1033, and 1083 mg/g) were higher than most of the other adsorbents. Furthermore, the potential adsorption mechanisms included pore filling, π-π interactions, hydrogen bonding, and electrostatic attraction. Even after 5 test cycles, the biochar retained over 75 % of its adsorption performance, highlighting its strong potential for applications in removing antibiotics from water.

Determining the impact of different types of biofuels on the quality of iron ore pellets

The object of this study is the process of roasting iron ore pellets. The study solves the task of replacing fossil fuel with plant-based fuel in order to reduce environmental load and ensure the stable quality of pellets, which is necessary for use in blast furnaces. The influence of biofuel content at a given temperature and air speed on the strength of pellets after roasting was studied. As a result of the research, it was established that the fuel content has a decisive effect on the strength of pellets. Among all types of fuel that were investigated, pellets with the addition of sunflower husks and wood had the highest strength that meets the requirements for blast furnace melting of 200 kilograms. The use of wheat straw and charcoal does not make it possible to completely replace solid fuel in the layer of pellets. The results show that the use of up to 0.36 % of sunflower husk makes it possible to increase the strength of burned pellets compared to samples without biofuel content. Adding all other considered types of fuel reduced the strength of the pellets. These results are explained by the different content of lignin, cellulose, and hemicellulose, which determines the characteristics of the biomass. The high content of cellulose and hemicellulose allows for high hydrophilicity due to the high number of OH groups and positively affects the formation of raw pellets. Volatile substances released during the combustion of biofuel contribute to the formation of spherical pores, as well as their uniform distribution, which prevents the propagation of cracks under load. Research results make it possible to establish the optimal roasting mode, decrease harmful emissions, and bring down costs by reducing fossil fuel consumption