Search Results (445)

An important contributor to environmental degradation is the industrial revolution, which has occurred in developed and developing nations. The present investigation aimed to tackle the escalating apprehensions regarding the discharge of various types of dyes from the paint, textile, and dyeing sectors. This research focuses on the adsorption performance of a newly developed system that uses cotton pod shell powder (CPSP) as a novel adsorbent to remove dye industry wastewater. The system has been designed, manufactured, and tested to be operationally efficient and cost-effective. The CPSP is a new adsorbent with desirable properties such as favorable functional groups and porosity, and analysis of its functional groups and porous nature was carried out using FTIR and SEM. The experimental data from the developed system showed that inlet dye concentration (50, 100, and 150 ppm), bed height (10, 20, and 30 cm), and flow rate (10, 15, and 20 mL/min) significantly affect the adsorption of dye industry wastewater by CPSP. Breakthrough curves were shown to be flow rate and bed depth dependent, according to the data. Significant experimentation was conducted on the developed system, and under optimized conditions. It was shown that the breakthrough point was affected by both bed height and flow rate. Evidence suggested that decreasing flow rate and concentration and raising bed height led to improved breakthrough and exhaustion times. At a concentration of 100 ppm and a flow rate of 15 mL/min, a bed depth of 20 cm was found to have the highest absorption capacity. Adam-Bohart, bed depth service time, and Yoon-Nelson models were utilized to examine the adsorption data. The results revealed that the developed system is effective, and the data obtained in this work can provide optimum operating conditions, suggesting its scalability to an industrial level for dye removal from wastewater by adsorption using CPSP as a novel adsorbent. Full article

Cocoa bean shell (CBS) is one of the main by-products of the cocoa processing industry and represents about 20% of the bean. This product has been suggested as a food ingredient due to its aroma, high dietary fiber, and polyphenol contents. This work shows the effect of grinding degree (GD) and grinding method on the physicochemical characteristics, total phenolic content (TPC), and antioxidant activity of an aqueous infusion of CBS. Three particle sizes of CBS powder and two milling methods (mechanical and electrical) were used to prepare a hot water infusion. The infusions presented a pH in the range of 5.37–5.80. In both husks and independently of the GD and the grinding method, the TPC was higher than 141 mg of gallic acid equivalent per g (GAE/g), an antioxidant activity greater than 304 µg of Trolox equivalent per g (µgTE/g). The results indicate that CBS can be an excellent alternative for the design of biofunctional beverages, giving added value to this agro-industrial residue of southeastern México. Full article

The conventional methods used to produce N-acetyl-β-D-glucosamine (GlcNAc) from seafood waste require pretreatment steps that use acids or bases to achieve the extraction and decrystallization of chitin prior to enzymatic conversion. The development of an enzymatic conversion method that does not require the pretreatment of seafood waste is essential for the efficient and clean production of GlcNAc. In this study, the annotated metagenomic assembly data of domesticated microbiota (XHQ10) were analyzed to identify carbohydrate-active enzymes (CAZymes), and an in-depth analysis of the high-quality genome FS13.1, which was obtained from metagenomic binning, was performed; this enabled us to elucidate the catabolic mechanism of XHQ10 by using shrimp shell chitin as a carbon and nitrogen source. The only β-N-acetylglucosaminidase (named XmGlcNAcase) was cloned from FS13.1 and biochemically characterized. The direct production of GlcNAc from shrimp shell powder (SSP) via the use of a chitin enzyme cocktail was evaluated. Under the action of a chitin enzyme cocktail containing 5% recombinant XmGlcNAcase and a crude XHQ10 enzyme solution, the yield and purity of the final conversion of SSP to GlcNAc were 2.57 g/L and 82%, respectively. This is the first time that metagene-derived GlcNAcase has been utilized to achieve the enzymatic conversion of untreated seafood waste, laying the foundation for the low-cost and sustainable production of GlcNAc. Full article

The construction industry contributes significantly to global carbon emissions, accounting for approximately 27% of total emissions. With the increasing demand for concrete, there is a growing need to explore alternative materials that can reduce environmental impact. This study investigates the potential of using oyster shell powder, a waste material, as a partial replacement for fine aggregates in concrete. The methodology involves replacing fine aggregates with oyster shell powder in varying proportions (0%, 10%, 20%, 30%, and 40%) and testing the compressive strength of the resulting concrete after 56 days. The concrete mix used in this study consists of 16.67% cement, 33.33% fine aggregates, and 50% coarse aggregates (10–20 mm). The findings show that increasing oyster shell content reduces the concrete’s compressive strength; however, at 40% replacement, the concrete still achieves a compressive strength of 30 MPa, which meets the required building strength standards. Additionally, the use of oyster shell powder reduces the unit weight of concrete by approximately 10% at the 40% substitution rate, due to the lower specific gravity of oyster shells compared to sand. This research highlights the potential of using oyster shell powder as a viable solution for mitigating oyster shell waste while providing an alternative material for fine aggregates in concrete. Full article

Seeking effective measures for the improvement of high-selenium and high-cadmium soils holds significant theoretical and practical importance for sustainable agricultural development. This paper focuses on conducting a site-specific soil survey in the characteristic agricultural product production area of Hefeng County, Enshi Prefecture, Hubei Province. Through field experiments, we compared 14 soil improvement methods across three techniques: chemical passivation remediation, agronomic regulation, and microbial remediation. The study investigated their impacts on rice Cd content, rice Se content, yield, and quality and conducted a comprehensive evaluation of the remediation effects of the different treatments. The experimental results indicate that (1) increasing the content of soil conditioners can enhance rice yields, with Treatment 14 showing the most significant increase, yielding an additional 257.3 kg per mu, representing a 55.62% increase. Treatment 12 also demonstrated a notable yield increase of 95.1 kg per mu, or a 20.55% increase. Lime, sepiolite, and shell powder can effectively reduce rice’s absorption of Cd. Treatment 9 resulted in the lowest Cd content in the rice, at 0.03 mg/kg, with a Cd reduction rate of 92%. The optimal application rates for this Cd reduction were 200 kg/mu of lime, 125 mL/mu of foliar inhibitor, and 50 kg/mu of carbon-silicon fertilizer. Treatment 12 achieved a rice Cd content of 0.11 mg/kg, with a 70% reduction in Cd, bringing the rice Cd content down to below 0.2 mg/kg, which meets the requirements of the National Food Safety Standard: Maximum Levels of Contaminants in Foods. In the comprehensive scoring of all treatments, considering four evaluation indicators—rice Cd content, rice yield, rice quality, and cost—Treatment 12 (300 kg/mu of soil conditioner + 50 kg/mu of carbon-silicon fertilizer) was found to be the optimal treatment through comparative scoring. It demonstrates good potential for ensuring safe rice production and can serve as a reference standard for repairing Cd-contaminated rice paddies in the local area, with promotional value. Full article

This study demonstrates the improvement of core loss through the reduction of eddy current loss in soft magnetic composites (SMCs) composed of TiO₂-coated Fe powder and epoxy resin. A thin and uniform TiO₂ insulating layer was successfully deposited on the surface of Fe powder via a sol-gel process, employing titanium (IV) butoxide (TBOT) as the precursor. Scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy analyses confirmed the formation of a core/shell Fe/TiO₂ structure, with a coating thickness of several tens of nanometers. Increasing the TBOT concentration and coating duration time led to an improved quality factor (Q factor) and a shift of the maximum Q factor values to higher frequency regions. Notably, the permeability was decreased slightly from 14.2 to 13.4, but the core loss, measured at various AC frequencies under 20 mT and then separated into hysteresis loss and eddy current loss at 1 MHz, was significantly reduced from 573 to 435 kW/m³ when the Fe powder was coated with TiO₂ using a 2.5 wt.% TBOT solution for 8 h. This reduction in core loss is attributed to the effective suppression of inter-particle eddy currents by the TiO₂ insulation layer. Full article

To enhance the energy release of Al powder in solid propellant, ploy (difluoroaminomethyl-3-methylethoxybutane) (PDF), which has difluoroamino (NF₂), was utilized to improve energy and promote combustion efficiency. In this study, Al with three distinct powder sizes (29 μm, 13 μm, and 1~3 μm) was coated with PDF using the solvent/non-solvent method, leading to the formation of Al/PDF composites. The morphology and characteristics of Al/PDF were then characterized. The results demonstrated that all powder sizes of Al/PDF had core-shell structures, and NF₂ of the PDF layer on the Al surface maintained the original structure. The TG curves indicated the amount of the PDF layer related to the powder sizes. Furthermore, Al/PDF exhibited greater hydrophobicity. NF₂ prompted Al/PDF, with better catalysis on ammonium perchlorate (AP) decomposition. Compared to Al powder, the ignition delay of Al/PDF was significantly shortened. For mixed samples of Al/PDF and AP, NF₂ shorted the ignition delay, improving combustion stability, extending the combustion duration, and forming volatile fluorine compounds. These findings underscore the effects of NF₂ in Al/PDF composites, which enhances the energy release of Al and holds promising potential applications. Full article

This study investigates the process of synthesizing eco-cement clinker using recycled powdered glass (RPG) and oyster shell residue (OSHL) as primary raw materials. Analysis of the mineral composition of RPG revealed that it primarily consists of silica and contains a high level of alkali metal oxides, while OSHL comprises a high-purity trigonal calcite structure, similar in chemical composition to limestone. Comparative analysis of the synthesized ecological cement and its hydration products showed that, after heat treatment at 1200 °C, the alkali metal content in the H12 sample significantly decreased, thereby meeting the standards for cement raw materials. The hydration process of RPG and OSHL ecological cement (ROEC) exhibited greater reactivity, with the presence of alkali ions (such as Na⁺ and K⁺) accelerating the cement hydration reaction and significantly enhancing early strength. Furthermore, as the curing time increased, the hydration products of ROEC became more uniform, ultimately consisting primarily of calcite. These findings indicate that the combination of RPG and OSHL offers a novel approach to cement synthesis, while reducing the content of alkali metal oxides, thereby aligning the cement clinker more closely with modern production standards. Full article

The sustainable management of aquaculture by-products is crucial for advancing circular economy practices. Mediterranean mussel shell waste, rich in calcium carbonate, presents a sustainable alternative to conventional liming materials, especially for mitigating soil acidification, a very important and common issue that limits crop productivity. This study evaluated the effectiveness of processed mussel shell waste in enhancing soil pH, organic matter, and nutrient availability. A 180-day pot experiment using highly acidic soil (pH < 4.5) collected from a local field was conducted in a Completely Randomized Design. Treatments involved two grain sizes of mussel shell powder (Fine: <1 mm; Coarse: 1–2 mm) at rates between 0.1 and 6%. Treated soil pH was measured monthly, whereas organic matter, available phosphorus (P), and exchangeable potassium (K) were measured at the beginning and the end of the experiment. The results revealed significant improvements in pH, organic matter, available phosphorus (P), and exchangeable potassium (K), particularly in the Fine Powder treatments. However, total nitrogen (N) remained unaffected. These findings highlight the potential of mussel shells as an eco-friendly and cost-effective amendment, advancing sustainable agriculture and waste recycling, thus contributing to broader conservation efforts by reducing the environmental footprint of aquaculture waste and supporting biodiversity and ecosystem resilience through sustainable resource management. Full article

Organic pollutants, especially dyes, are seriously hazardous to the aquatic system and humans due to their toxicity, and carcinogenic or mutagenic properties. In this study, a biochar prepared from agricultural waste (pecan shells) via pyrolysis was applied to remove the dye pollutant Congo Red from wastewater to avoid a negative effect to the ecosystem. This study also investigated the effect of preparation conditions (temperature and heating rate) on the physicochemical properties and the adsorption performance of biochars. The physicochemical properties of the biochar were characterized using scanning electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The adsorption performance of the biochar was evaluated for Congo Red removal. The results showed that biochar prepared at 800 °C with a heating rate of 20 °C/min (PSC-800-20) exhibited a higher specific surface area of 450.23 m²/g and a higher adsorption capacity for Congo Red (130.48 mg/g). Furthermore, adsorption experiments indicated that the pseudo-second-order and Langmuir models fitted well with the adsorption kinetics and isotherms of the biochar derived from pecan shells, respectively. Additionally, the PSC-800-20 biochar demonstrated a stable adsorption capacity over multiple cycles, suggesting its potential for regeneration and reuse in wastewater treatment applications. Therefore, the biochar derived from agricultural waste presents a promising and sustainable solution for the removal of toxic dye pollutants from wastewater. Full article

Eco-friendly castor oil-based composites with a high content of clam shell powder were prepared in this study. Biomass composites were prepared by blending castor-oil-based polyurethane prepolymer (COPU) with a filler consisting of high-content clam shell powder (CSP), named CSP-COPU. The structure, microstructure, mechanical properties, and thermal stability of the composites were investigated. The results showed that even at a loading as high as 75 wt.% of the CSP filler, the composite still exhibited good tensile strength and elongation at break. Furthermore, compared with the CSP-COPU composites, TCOS-50 synthesized through blending OH-terminated castor oil-based polyurethane prepolymer (TCOPU) and CSP filler proved that the chemical bond between COPU containing terminal -NCO groups and CSP containing active -OH groups was the key reason to obtaining the composite material with desirable properties. These findings provide prospects for applying biomass-loaded CSP-COPU composites in the packaging industry while contributing to carbon peak achievement and carbon neutrality. Full article

Coating conductive nanoparticles onto the surface of hollow glass microspheres (HGMs) is essential for broadening their applications. However, the low density and high specific surface area of HGM powders, along with the thin walls of the cavity shells and poor surface adhesion, pose challenges for the uniform attachment of functional particles. In this study, we developed a novel integrated process that combines flotation, hydroxylation, and amination pretreatment for HGMs with in situ surface polymerization to achieve a uniform coating of polypyrrole (PPy) on the surface of HGMs. We explored the corresponding growth process and coating mechanism. Our findings indicate that the amount of coating, particle size, and uniformity of PPy on the surface of HGMs are significantly influenced by the pretreatment and the in situ polymerization time, as well as the microspheres/pyrrole feedstock ratio. The in situ polymerization on the surface of HGMs resulted in a uniform encapsulation of spherical PPy, with the average particle size of PPy-coated HGMs (PPy@HGMs) increasing by 14.60% compared to the original HGMs. The elemental nitrogen in the PPy@HGMs primarily exists in the form of C-N and N-H bonds. This study demonstrates that the surface functional groups of HGMs engage in chemical bonding and interactions with PPy molecules. Mechanistic analysis reveals that the hydroxyl and amino groups enriched on the surface of the pretreated HGMs serve as activation centers, facilitating the uniform enrichment of pyrrole monomers and promoting chain growth polymerization of the conjugated chain through nucleophilic and electrophilic interactions with the subamino groups in the pyrrole ring. Additionally, the reaction between the Lewis acid properties of PPy and the Lewis-type electron-donating amino groups in KH550 fosters strong bonding and the formation of a robust interface. Full article

In this study, hydrogel films of biocomposite comprising bacterial cellulose (BC) and silk (S) were successfully fabricated through a simple, facile, and cost-effective method via biosynthesis by Acetobacter xylinum in a culture medium of coconut skim milk/mature coconut water supplemented with the powders of thin-shell silk cocoon (SC). Coconut skim milk/mature coconut water and SC are the main byproducts of coconut oil and silk textile industries, respectively. The S/BC films contain protein, carbohydrate, fat, and minerals and possess a number of properties beneficial to wound healing and tissue engineering, including nontoxicity, biocompatibility, appropriate mechanical properties, flexibility, and high water absorption capacity. It was demonstrated that silk could fill into a porous structure and cover fibers of the BC matrix with very good integration. In addition, components (fat, protein, etc.) in coconut skim milk could be well incorporated into the hydrogel, resulting in a more elastic structure and higher tensile strength of films. The tensile strength and the elongation at break of BC film from coconut skim milk (BCM) were 212.4 MPa and 2.54%, respectively, which were significantly higher than BC film from mature coconut water (BCW). A more elastic structure and relatively higher tensile strength of S/BCM compared with S/BCW were observed. The films of S/BCM and S/BCW showed very high water uptake ability in the range of 400–500%. The presence of silk in the films also significantly enhanced the adhesion, proliferation, and cell-to-cell interaction of Vero and HaCat cells. According to multiple improved properties, S/BC hydrogel films are high-potential candidates for application as biomaterials for wound dressing and tissue engineering. Full article

To meet the growing demand for sustainable aquaculture, plant proteins are being explored as alternative sources in fish diets. However, some plant proteins can have adverse health effects on fish, prompting research into functional feed ingredients to mitigate these issues. This study investigated pistachio shell powder (PSP), rich in antioxidants, as a functional feed ingredient for rainbow trout (Oncorhynchus mykiss). The effects of PSP inclusion (0%, 0.5%, 1%, 2%) on growth performance, intestinal health, and gut microbiota were assessed in fish fed either a fishmeal (FM) or plant meal (PM) diet over a 12-week feeding period. The results indicated that PSP inclusion at 1% significantly (p < 0.05) improved weight gain and growth performance in FM treatments, with no impact on growth in PM treatments. No significant differences were observed in other growth parameters, intestinal morphology, or oxidative stress markers, although a trend toward the downregulation of inflammatory genes was noted in PM treatments at 2% PSP inclusion. PSP inclusion did not significantly alter gut microbiota alpha diversity but affected beta diversity at the 0.5% level in the FM treatments (p < 0.05). Differential abundance analysis of gut microbiota revealed taxa-specific responses to PSP, particularly the genus Candidatus arthromitus, increasing in relative abundance with PSP inclusion in both the FM- and PM-based treatments. Overall, PSP inclusion up to 2% did not have significant adverse effects on the growth, intestinal health, or antioxidant status of rainbow trout. Full article

Carbon-based electrodes have recently been most widely used in P-MFC due to their desirable properties such as biocompatibility, chemical stability, affordable price, corrosion resistance, and ease of regeneration. In general, carbon-based electrodes, particularly graphite, are produced using a complex process based on petroleum derivatives at very high temperatures. This study aims to produce electrodes from bio-pitch and charcoal powder as an alternative to graphite electrodes. The carbons used to manufacture the electrodes were obtained by the carbonisation of Robinia pseudoacacia and Azadirachta indica wood. These carbons were pulverised, sieved to 50 µm, and used as the raw materials for electrode manufacturing. The binder used was bio-pitch derived from coconut shells as the raw materials. The density and coking value of the bio-pitch revealed its potential as a good alternative to coal-tar pitch for electrode manufacturing. The electrodes were made by mixing 66.50% of each carbon powder and 33.50% of bio-pitch. The resulting mixture was moulded into a cylindrical tube 8 mm in diameter and 80 mm in length. The raw electrodes obtained were subjected to heat treatment at 800 °C or 1000 °C in an inert medium. The electrical resistivity obtained by the four-point method showed that N1000 has an electrical resistivity at least five times lower than all the electrodes developed and two times higher than that of G. Fourier-transform infrared spectroscopy (FTIR) was used to determine the compositional features of the samples and their surface roughness was characterised by atomic force microscopy (AFM). Charge transfer was determined by electrical impedance spectroscopy (EIS). The FTIR of the electrodes showed that N1000 has a spectrum that is more similar to that of G compared to the others. The EIS showed the high ionic mobility of the ions and therefore that N1000 has a higher charge transfer compared to G and the others. AFM analysis revealed that N1000 had the highest surface roughness in this study. Full article