Search Results (124)

To avoid dependence on conventional raw materials, global emphasis has been placed on obtaining alternative plant celluloses and the chemical synthesis of cellulose. The use of synthetically derived cellulose as a precursor for cellulose nitrates (NCs) is currently absent in global practice, which underscores the undoubted relevance of this research. Cellulose nitrate (NC) was synthesized in a 138% actual yield by nitration of synthetic cellulose (SC)—a new type of cellulose—prepared by electropolymerization from an aqueous glucose solution in the presence of catalytic tungsten–vanadium heteropolyacid of the 1–12 series with the chemical formula H₆[PW₁₀V₂O₄₀]: a nitrogen content of 11.83%, a viscosity of 198 mPa·s, a high solubility of 91% in an alcohol–ether solvent, and an ash content of 0.05%. SEM provided a general concept of the morphological structure of SC and SC-derived NC. The initial SC consisted of flat, curly fibers with a smooth surface approximately 10–20 μm wide, with no aggregation observed. The fibers of SC-derived NC had a cylindrical shape with a diameter of up to 25 μm and a rough surface. FT-IR spectroscopy revealed that SC and SC-derived NC have the main functional groups characteristic of classical cellulose (3346, 2901, 1644, 1429, 1162, and 1112 cm⁻¹) and nitrate esters of cellulose (1650, 1278, 832, 747, and 689 cm⁻¹), respectively. For the first time, a full-profile analysis discovered that SC is made up of the monoclinic phase of cellulose Iβ with an antiparallel chain arrangement. SC with a crystallinity index (CrI) of 81–86% was shown to undergo amorphization upon nitration, with the CrI declining to 17% and the crystallite sizes decreasing from 44 × 62 × 59 × 94 Å to 29 × 62 × 26 × 38 Å. Coupled TGA/DTA revealed that SC exhibits a high-temperature endothermic peak of decomposition of 374 °C, with a weight loss of 84%. The thermostable SC-derived NC exhibits a high onset temperature of intense decomposition of 200 °C and an exothermic peak of 208 °C, with a weight loss of 88%, and is characterized by a high specific heat of decomposition of 7.74 kJ/g. This study provides new insights into the functionalization of SC with a high degree of polymerization, expanding the classical concepts of cellulose nitration. Full article

The mobilization of complex microbial communities from natural resources can be a valuable alternative to the use of single-species biofertilizers when it comes to the decomposition of plant residues. However, the functioning and interaction of microorganisms within these communities remain largely unexplored. Our task was to investigate the cellulose-degrading community using the biofertilizer BAGS (peat-based compost with straw) as an example and define its active component. For this, we monitored the succession of the biofertilizer’s taxonomic composition during two consecutive rounds of its six-month composting process, varying in the applied mineral fertilization. The amount of added nitrogen significantly affected the performance of the biofertilizer, contributing to its high cellulolytic activity. Based on the network analysis, the biofertilizer’s mature phase was determined, and its characteristic ASVs (amplicon sequence variants) were described. Metagenomic analysis of this phase revealed MAGs (metagenome-assembled genomes) corresponding to these ASVs, which contained genes for cellulose and aromatics degradation, as well as genes for nitrogen and sulfur pathways, including anaerobic nitrate reduction and thiosulfate oxidation. Thus, we propose that the cellulose-decomposing bacterial component of BAGS, associated with the mature phase, occupied different trophic niches, not limited to cellulose degradation, which should be considered when designing natural or artificial microbial systems for the decomposition of plant residues. Full article

As water scarcity and pollution increase in rural communities in some parts of developing countries, there is a need to find simple ways to improve the quality of contaminated water. In this research, bagasse-based cellulose membranes were prepared and evaluated in a simple filtration system and compared with polycaprolactone membranes (PCL) and bagasse-based cellulose/PCL membranes for the removal of total coliform bacteria, Escherichia coli and other physical and chemical contaminants from contaminated water. Cellulose offers many opportunities in filtration technology due to its physical and chemical characteristics that allow its use in the design of membranes with flexible capabilities and specific applications. The membranes were characterized physically, chemically and mechanically, finding similarity in mechanical properties and differences in porosity. The membranes were tested in a filtration system and PCL membranes were more effective in removing turbidity (94.5%), color removal (70%) and phosphorus removal (50%), while cellulose membranes were better at retaining fecal coliforms (84.5%) and E. coli (90.8%). Statistical analysis (one-way ANOVA, p < 0.05) confirmed significant differences among the three membrane types for turbidity, apparent color, and nitrate, while no significant differences were observed for pH, conductivity, and phosphorus. These results suggest that the use of the membranes could help to improve the quality of polluted water and more studies are needed in order to improve their efficiencies. Full article

Silver tarnish is a major issue in many heritage institutions. Applying lacquer is frequently used when preventive conservation approaches are limited. The service lifetime of the lacquer has a strong impact on resources and sustainability. Little systematic work has been published on this. This work explores three thresholds on lifetime—visual, reversibility, and loss of protection. It uses thermodynamic modelling to predict lacquer lifetime from aging at four temperatures. Samples on sterling silver with Frigilene lacquer were used and aging was assessed with a Bruker Alpha FTIR using external reflectance. The FTIR ratio of produced carbonyl peak to nitrate peaks was used to quantify the aging. The commonly used C-O-C peak was found to suffer from dispersion in a high proportion of samples, so could not be used in this study. The results were compared with measurements of lacquer on silver objects displayed in showcases and from store (with almost no light exposure). Spectra were obtained with the Bruker Alpha or an Inspect infra-red microscope. Autocatalytic effects through concentration of emitted nitrogen oxide gases have also been explored using diffusion tubes and gas ingress analysis. No significant concentration was observed. The thresholds were clearly established, and the model produced similar results to the natural aging studied. Full article

The development of stable and efficient heterogeneous Fenton oxidation for organic pollutant degradation is crucial to avoid iron sludge formation and cumbersome filtration processes. In this study, iron oxide/carbon aerogel was prepared via the sol–gel method, freeze-drying, and high-temperature carbonization using iron nitrate heptahydrate, ammonium hydroxide, and cellulose as raw materials, with polyvinylimine serving as the crosslinking agent. To enhance the pH adaptability of the catalyst, copper and cerium elements were introduced. The characterization results demonstrate the iron (III) oxide within the carbon aerogel, achieving phenol degradation efficiency exceeding 95% within 120 min. Meanwhile, the introduction of copper and cerium accelerated the degradation of phenol while maintaining a certain catalytic degradation effect at pH 5-7. In addition, the catalyst exhibited excellent recyclability, retaining 85% of its initial degradation efficiency after five reaction cycles. This work offers a new method for the development of heterogeneous Fenton catalysts. Full article

This study aimed to determine the practical efficacy of passive eDNA samplers (PEDS) for monitoring fish diversity in riverine ecosystems. It investigated the utility of environmental DNA (eDNA) in accurately depicting fish composition and diversity within the Lancang River. Environmental DNA technology, particularly PEDS, may be used as a substitute for traditional water filtration techniques. However, its effectiveness in natural water ecosystems remains to be proven. The filter materials included mixed cellulose acetate and nitrate (MCE), nylon (NL), glass fiber (GF), and polyvinyl chloride filter membrane (PVC). This study used four different types of filters, each with identical pore sizes and dimensions but constructed from various materials, to assess eDNA capture under laboratory and field conditions in the water samples. The filter materials included mixed cellulose acetate and nitrate (MCE), nylon (NL), glass fiber (GF), and polyvinyl chloride filter membrane (PVC). Environmental DNA macrobarcoding was used to analyze fish biodiversity and to understand the environmental effects on species distribution. Our study identified 50 fish species inhabiting the Lancang River, with equal representation of exotic and native species. A comparative analysis of four filter-based environmental DNA samplers and traditional environmental DNA sampling methods demonstrated comparable species richness. Redundancy analysis indicated that environmental variables, elevation, electrical conductivity, salinity, and chlorophyll-a significantly influenced the distribution patterns of both non-native and native fish species in the river. This study highlights the significance of eDNA technology in evaluating fish diversity across diverse habitats, thereby establishing a theoretical framework for the sustained monitoring and management of fish biodiversity in protected areas. Full article

Hydrogels are widely known for their ability to increase soil water retention and for their potential slow nutrient release mechanism. They have been constantly improved to meet the growing demand for sustainability in agriculture. Research focused on the development of biodegradable hydrogels, produced from industrial cellulose waste, are an ecological and efficient alternative soil ameliorant for the improvement of agricultural land. The objective of this study was to evaluate the impacts of two types of hydrogel (processed in a glass reactor versus a twin-screw extruder) on soils with different textures (clay and sandy loam), testing their water retention capacity, nitrogen leaching, and effects on seed germination. The methodology included the evaluation of water retention capacity at different pressures with different hydrogel addition rates in the soil, leaching tests in columns filled with soil and hydrogel layers, and germination tests of sorghum and corn. The results indicated that the addition of hydrogel significantly improved water retention, especially in sandy loam soils. The hydrogels also reduced nitrogen leaching, acting as nitrification inhibitors and limiting the conversion of ammonium to nitrate, with greater effectiveness in clayey soils. In the tested formulations, it was observed that the hydrogel doses applied to the columns favored nitrogen retention in the region close to the roots, directly influencing the initial stages of germination. This behavior highlights the potential of hydrogels as tools for directing nutrients in the soil profile, indicating that adjustments to the C:N ratio, nutrient release rate, and applied doses can optimize their application for different crops. Full article

Farming is an important development direction of agriculture in the future, which is affected by various environmental factors, among which light plays an important role, and it is essential for the growth of organisms in nature. LED technology can regulate the growth and development of vegetables by adjusting the spectral composition of light. In order to explore light quality formulation with the aim of improving the quality and yield of celery, we set up six experimental treatments: W (white light), R (red light), B (blue light), 3R1B (red light/blue light = 3:1), 4R1B (red light/blue light = 4:1), and 5R1B (red light/blue light = 5:1). The results indicated that the 3R1B and 4R1B illumination treatments were conducive to promoting the growth of celery, enhancing plant height and root length. Specifically, the 3R1B treatment optimized the nutritional quality of celery by increasing the levels of soluble protein, soluble sugar, and total flavonoids while reducing nitrate and cellulose contents and elevating the anthocyanin content in petioles. Additionally, both treatments enhanced the contents of Ca and Mg in celery leaves and petioles. Furthermore, the 3R1B treatment promoted the accumulation of photosynthetic pigments, upregulated the activities of ANS and FNS enzymes, and induced the upregulation of gene expression levels of FNS and ANS, thereby enhancing the nutritional value of celery. Full article

Cotton waste, a growth medium for Volvariella volvacea, has significant commercial and nutritional value. Under controlled environmental conditions, substrate nutrient composition and microorganisms affect the growth of V. volvacea. In this study, the changes in the nutrient content of the substrate at different stages of fruiting body development were compared based on an 86% waste cotton substrate, and microbial diversity was studied via 16S rRNA analysis. The results indicated that there were significant differences in nutrient content in the substrate at different stages of fruiting body development. The total contents of carbon, nitrogen, and phosphorus initially increased but then decreased due to nutrient absorption and utilization by V. volvacea. It was also found that large amounts of organic nitrogen decomposed into more readily utilizable inorganic nitrogen. The nutritional content and microbial community structure of the substrate during the egg stage significantly differed from those during the other four stages, making the egg stage the most critical period in cultivation. Through correlation analysis between nutrient content and microbial differences, it was found that differential microbial taxa (Beijerinckiaceae, Burkholderiales, Chitinophaga jiangningensis, etc.) with nitrogen fixation, denitrification, and cellulose decomposition functions were significantly related to carbon- and nitrogen-related indicators such as nitrate nitrogen, microbial biomass carbon, and alkali-hydrolyzed nitrogen. These microorganisms play important roles in determining the variation in the nutritional profile of the substrate. This study provides a theoretical basis for promoting the absorption and utilization of nutrients by V. volvacea by altering the structure of the microbial community of the growth substrate. Full article

Background/Objectives: The rise of bacterial resistance and the search for alternative, biocompatible antimicrobial materials have driven interest in natural-based nanocomposites. In this context, silver nanoparticles (AgNPs) have shown broad-spectrum antibacterial activity, and bacterial cellulose (BC) is widely recognized for its high purity, hydrophilicity, and biocompatibility. This study aimed to develop a bio-based BC–AgNP nanocomposite via green synthesis using Astrocaryum aculeatum (tucumã) extract and assess its antimicrobial performance for wound dressing applications. Methods: BC was biosynthesized via green tea fermentation (20 g/L tea and 100 g/L sugar) and purified prior to use. AgNPs were obtained by reacting aqueous tucumã extract with silver nitrate (0.1 mmol/L) at pH (9) and temperature (40 °C). BC membranes were immersed in the AgNPs dispersion for 7 days to form the nanocomposite. Characterization was performed using UV–Vis, DLS, TEM, SEM–EDS, FTIR, XRD, ICP–OES, and swelling analysis. Antibacterial activity was evaluated using the disk diffusion method against Staphylococcus aureus and Escherichia coli (ATCC 6538 and 4388). Results: The UV–Vis spectra revealed a gradual decrease in the surface plasmon resonance (SPR) band over 7 days of incubation with BC, indicating progressive incorporation of AgNPs into the membrane. ICP analysis confirmed silver incorporation in the BC membrane at 0.00215 mg/mL, corresponding to 15.5% of the initial silver content. Antimicrobial assays showed inhibition zones of 6.5 ± 0.5 mm for S. aureus and 4.3 ± 0.3 mm for E. coli. Conclusions: These findings validate the successful formation and antimicrobial performance of the BC–AgNP nanocomposite, supporting its potential use in wound care applications. Full article

Excessive use of fertilizers will not only cause the enrichment of soil N nutrients, soil secondary salinization, soil acidification, and an imbalance of the soil microbial community structure, but will also lead to the nitrate content of vegetables and the ground water exceeding the standard. The application of bio-organic fertilizer could reduce the amount of mineral fertilizer used. However, the effects of nitrogen reduced with different bio-organic fertilizers on soil chemical properties, microbial community structure, and the yield and quality of radish are not clear. In a field experiment, we designed six fertilization treatments: no fertilization (CK), conventional fertilization (T1), a total nitrogen reduction of 20% (T2), and a total nitrogen reduction of 20% with “No. 1”, “Seek” or “Jiajiapei” bio-organic fertilizers. The results showed that nitrogen reduction of 20% with Bacillus bio-organic fertilizer (N1) significantly increased the organic matter, pH, total nitrogen content, and the relative abundance of Bacillus and Streptomyce in the soil compared with T1. RDA analysis showed that the pH, organic matter content, invertase and fluorescein diacetate enzyme activity of the soil were significantly correlated with the soil microbial community structure. In addition, the yield and Vc content in radish were increased with the application of bio-organic fertilizers, while on the contrary, the nitrate and cellulose content were decreased, and the N1 treatment showed the best effect. Moreover, the yield had a significant positive correlation with Bacillus. Overall, nitrogen reduction with bio-organic fertilizers, especially full-effective “No. 1” enriched with Bacillus, could alter the soil microbial community structure and effectively improve soil fertility, which in turn enhanced the yield and quality of radish. An application of Bacillus bio-organic fertilizer was an effective strategy to improve soil quality and vegetable safety. Full article

Appropriate calcium treatments help maintain the appearance, nutritional quality, and postharvest quality of apples, reducing losses during storage. This study investigated the effects of different calcium preparations on the fresh-cut quality and ultrastructure of ‘Starkrimson’ apples. The treatments included control (CK), calcium chloride (T1), sorbitol-chelated calcium (T2), and calcium nitrate (T3). The results demonstrated that sorbitol-chelated calcium significantly inhibited the decline in fresh-cut firmness and pectin content while reducing the increase in cellulose content and minimizing ultrastructural damage. Apples treated with sorbitol-chelated calcium maintained the best fresh-cut hardness and soluble pectin contents, which were 35.71% and 15.42% higher than that of CK on the 12th day, and the cellulose was 27.08% lower than that of CK. Under transmission electron microscopy, the pulp cell surface in the T2 group remained intact, with no bending or deformation, and the middle lamella was well preserved. Additionally, T2 treatment promoted the expression of aroma-related genes during fruit storage. Sorbitol-chelated calcium effectively preserved color and significantly reduced the browning and microbial spoilage of fresh-cut apples, particularly postharvest pathogen growth. The study demonstrates that sorbitol-chelated calcium preserves fresh-cut apple quality by reinforcing cell wall integrity through calcium-mediated crosslinking, suppressing pectin degradation and cellulose accumulation, and activating aroma-related genes (AAT1, AAT2, LOX) to enhance volatile synthesis, thereby reducing microbial spoilage and enzymatic browning during storage. Full article

The development of sustainable nanofiltration membranes requires alternatives to petroleum-derived polymer substrates. This study demonstrates the successful use of an eco-friendly cellulose acetate/cellulose nitrate (CA/CN) blend substrate for fabricating high-performance modified thin-film composite (mTFC) membranes. A dense, non-porous polyamide (PA) selective layer was formed via the interfacial polymerization method and modified with 0.05–0.1 wt.% HKUST-1 (Cu₃BTC₂, MOF-199). Characterization by FTIR, XPS, SEM, AFM, and contact angle measurements confirmed the CA/CN substrate’s suitability for TFC membrane fabrication. HKUST-1 incorporation created a distinctive ridge-and-valley morphology while significantly altering PA layer hydrophilicity and roughness. The mTFC membrane performance could be fine-tuned by the controlled incorporation of HKUST-1; incorporation through the aqueous phase slowed down the formation of the PA layer and significantly reduced its thickness, while the addition through the organic phase resulted in the formation of a denser layer due to HKUST-1 agglomeration. Thus, either enhanced permeability (123 LMH bar⁻¹ with 0.05 wt.% aqueous-phase incorporation) or rejection (>89% dye removal with 0.05 wt.% organic-phase incorporation) were achieved. Both mTFC membranes also exhibited improved heavy metal ion rejection (>91.7%), confirming their industrial potential. Higher HKUST-1 loading (0.1 wt.%) caused MOF agglomeration, reducing performance. This approach establishes a sustainable fabrication route for tunable TFC membranes targeting specific separation tasks. Full article

Biochar (BC) is a widely studied economic and environment-friendly material. However, its application is limited by its underdeveloped pore structure, small specific surface area, low degree of graphitization, and difficulty in being separated from liquids during the application process. Raw cotton contains almost 100% cellulose and has a high yield for preparing biochar. A novel type of magnetic biochar composite was prepared by the impregnation–calcination method using cotton and iron nitrate nonahydrate(Fe(NO₃)₃·9H₂O). The material was characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, thermogravimetric analysis (TG), and specific surface area testing (BET). The results show that Fe_xO_y nanoparticles with a uniform morphology and an average particle size of less than 20 nm are embedded in the composite; the saturation magnetization strength of the composite material reaches 21.6 emu/g; and compared to the original biochar, the composite material has a larger specific surface area (326 m²/g). As an adsorbent, the composite material has a fast removal rate for Pb²⁺ of 95% in 50 min. The Langmuir model calculation results show that the maximum adsorption capacity of the composite for Pb²⁺ is 252.7 mg/g. Fe_xO_y-BC easily achieves solid–liquid separation and can be recycled for Pb²⁺ wastewater treatment through adsorption–desorption–regeneration. Full article

To investigate the feasibility of cellulose extraction from lignocellulosic waste biomass using ionic liquids—a sustainable and efficient approach—for preparing cellulose aerogel adsorbents, we employed a fully green amino acid-derived ionic liquid, cysteine nitrate ([Cys][NO₃]), for cellulose separation from diverse biomass sources. The extracted cellulose, with a purity range of 83.8–93.9%, was processed into cellulose aerogels (CAs) via a conventional aerogel preparation protocol. The resulting CA exhibited promising adsorption capacities, including 0.2–11.6 mg/g for Na⁺, 4.4–19.9 mg/g for Ca²⁺, 4.15–35.6 mg/g for Mg²⁺, and 1.85–13.3 mg/g for Cd²⁺, as well as 9.7–17.7 g/g for engine oil. These results demonstrate the presence of effective mass transfer channels in the CA, proving that the cellulose’s fibrillation capacity was preserved in the pre-treatment. This study illuminates the potential of this green, straightforward method for preparing aerogels from cellulose derived from waste biomass, with promising applications in wastewater treatment and material recovery. Full article