Search Results (4,815)

With the growing depth of underground mining, issues surrounding solid waste storage and the effective use of mine water have become pivotal to achieving sustainable mining practices. The complex ionic composition of mine water impacts the performance of traditional cemented tailings backfill (CTB) materials. Gold mine tailings, combined with cement, were repurposed as the cornerstone raw materials in this investigation. Solutions with identical target concentration gradients for Cl⁻, SO₄²⁻, and HCO₃⁻ were prepared separately using NaCl, Na₂SO₄, and NaHCO₃, respectively, with each salt dosed to achieve the desired anion concentration. These solutions served as mixing water for preparing samples with tailings and cement. Strength, energy dissipation characteristics, and microstructure of CTB were investigated by single-axis compression test, XRD, and SEM-EDS analysis. Experimental results demonstrate that adding three reagents—NaCl, Na₂SO₄, and NaHCO₃ (covering Cl⁻, SO₄²⁻, and HCO₃⁻ ions, respectively)—at appropriate concentrations enhances mechanical properties. At their optimum concentrations, these salts increased the compressive strength of CTB by approximately 30%, reaching ~4 MPa. However, further increases in salt concentration produced inconsistent strength responses, with bicarbonate-containing mixtures exhibiting the most pronounced strength reduction. These effects are primarily attributed to competition between the introduced anions and cement hydration reactions, which alters the pore structure and consequently the density and strength of the hardened matrix. Incorporating different ion-covering backfill at appropriate concentrations enhances mechanical strength. These findings provide new opportunities for CTB mix design and mine water utilization. However, as this study considered only single-ion systems, further investigation is needed to elucidate the combined effects of multiple ions present in actual mine water. Full article

The growing demand for flexible and environmentally friendly energy storage systems has increased interest in new electrolyte materials capable of operating at low temperatures. In this work, hydrogel polymer electrolytes based on aqueous choline lactate solutions were developed and evaluated for supercapacitor applications. Choline lactate was synthesized from biodegradable and low-toxicity substrates and characterized using spectroscopic and thermal analysis methods. A series of aqueous electrolytes with different salt concentrations was prepared, and their viscosity, density, and ionic conductivity were investigated to determine the optimal composition for hydrogel preparation. The obtained hydrogels were synthesized by photopolymerization and showed good flexibility, transparency, and structural stability without electrolyte leakage. Thermal analysis revealed that the presence of choline lactate effectively suppressed water crystallization, reducing the phase transition temperature of the hydrogel systems below −44 °C. Ionic conductivity increased with electrolyte content and reached 22.3 mS·cm⁻¹ at room temperature for the hydrogel containing 90 wt% electrolyte. Mechanical measurements showed that increasing electrolyte concentration improved flexibility but reduced stiffness and compressive strength. Electrochemical tests demonstrated stable supercapacitor operation in the temperature range from 25 °C to −20 °C, although lower temperatures led to decreased capacitance and increased internal resistance. The results indicate that choline lactate-based hydrogels are promising candidates for sustainable low-temperature energy storage devices. Full article

Industrial processing of tomato generates large amounts of tomato pomace (TP), whose disposal and stabilization are challenging due to its high moisture content. This study evaluated, for the first time, the effects of increasing inclusion levels of enzymatic pre-treatment, vacuum paddle-dehydrated TP (ETP), in extruded diets for adult dogs. Three diets containing 0%, 2% or 4% ETP, replacing wheat bran and sunflower meal, were produced. Three two-bowl tests assessed palatability, and a feeding trial was performed using a four 3 × 3 Latin square design with 12 healthy adult Beagle dogs across three 28-day periods. Inclusion of ETP had negligible effects on the chemical composition of diets and kept unaffected palatability, body weight, food intake, fecal consistency and output. Fecal pH was lower, and valerate proportion was higher, in dogs fed the 2% ETP diet. All diets exhibited high digestibility (>90%) without effects of dietary treatments. Overall, ETP, a locally sourced co-product of the food industry, may represent a more sustainable alternative to imported raw materials, although further studies are needed to explore its effects on fecal microbiota and health-related parameters. Full article

Graphene-based nanosheets (GNS), including graphene, graphene oxide (GO), reduced graphene oxide (rGO), and graphene nanoplatelets (GNPs), have attracted increasing attention for developing high-performance and sustainable cementitious composites. Compared with conventional dispersion strategies, graphene-based coating strategies enable the targeted localization of GNS at critical interfacial transition zones (ITZs), thereby maximizing their reinforcing efficiency while mitigating agglomeration issues. This review systematically summarizes recent advances in GNS coating technologies for cementitious composites, including physical adsorption, chemical assembly, electrophoretic deposition, and in situ growth. The effects of GNS coatings on interfacial engineering, mechanical performance, durability enhancement, and smart functionalities are critically discussed. Existing studies indicate that GNS coatings can improve strength, crack resistance, impermeability, and resistance to chloride ingress, freeze–thaw cycles, and other degradation processes mainly through ITZ densification and microstructure refinement. However, these benefits are strongly dependent on the coating method, substrate type, and stability of the graphene–substrate interface in calcium-rich alkaline pore solutions. In particular, physically adsorbed GO coatings may suffer from desorption or Ca²⁺-induced aggregation, chemically assembled coatings require further validation beyond laboratory-scale systems, and electrophoretic deposition is mainly applicable to electrically conductive substrates. In addition, localized conductive networks created by GNS coatings facilitate multifunctional properties such as self-sensing, electromagnetic shielding, and electrothermal performance. From a carbon-neutrality perspective, the improvements in mechanical properties and durability provide opportunities to reduce material consumption, extend service life, and lower life-cycle carbon emissions. Nevertheless, their carbon-neutral contribution should be verified through quantitative life-cycle assessment rather than inferred directly from strength or durability enhancement alone. Finally, the remaining challenges associated with large-scale implementation, long-term stability, cost-effectiveness, and field-scale validation are discussed. Particular attention is given to the fact that most existing evidence is derived from laboratory-scale specimens rather than real structural elements exposed to service environments. Full article

(1) Background: Electroplating sludge (ES) and water-washed municipal solid waste incineration fly ash (WFA) are classified as hazardous solid wastes, and their conventional disposal approaches trigger severe heavy metal pollution. Conventional colored ceramic glazes heavily depend on virgin mineral ores and synthetic colorants; therefore, sustainable alternative feedstocks are urgently required. (2) Methods: WFA and ES were compounded with red clay and shale to fabricate low-environmental-risk black glazes. Material microstructures and phase compositions were characterized via X-ray diffraction (XRD) and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS). Single-factor experiments were conducted to optimize the raw material ratios and sintering schedules, while heavy metal leaching toxicity was evaluated following national standard HJ/T 300-2007. (3) Results: The optimal composite formulation consists of 26.1 wt% WFA, 30.4 wt% ES, 26.1 wt% red clay and 17.4 wt% shale. Smooth, defect-free pure black glaze specimens were fabricated after sintering at 1280 °C for 90 min under a weak reducing atmosphere. Heavy metal ions were stably immobilized within the silicate crystalline and amorphous glass phases, with all leaching concentrations well below the national standard thresholds. (4) Conclusions: The proposed technology achieves the high-value co-valorization of two hazardous solid wastes while producing low-environmental-risk colored ceramic glazes, providing a feasible strategy for solid waste recycling and the low-carbon development of the ceramic manufacturing industry. Full article

In arid regions, potentially toxic elements (PTEs) can accumulate in oasis farmland soils, posing risks to both ecosystems and human health and threatening the long-term sustainability of agricultural production. However, we still lack a clear understanding of how multiple elements co-accumulate and what non-linear processes drive their buildup. Here, we investigated typical agricultural soils in the Aksu area of Xinjiang. We measured 12 elements (As, Cr, Cu, Ni, Zn, Co, V, Se, F, Ba, Sn, Mn) in 28 surface samples. To assess the pollution levels, we used three indices: the single-factor index (P_i), the geo-accumulation index (I_geo), and the Nemerow composite index. Source apportionment was performed with positive matrix factorization (PMF). We then built an XGBoost model to predict the Nemerow index, and applied SHAP (Shapley additive explanations) to quantify the marginal contribution and non-linear response of each element. Our results show that the average concentrations of Se, F, and As are 1.47, 1.27, and 1.35 times the national background values, respectively. The exceedance rate (P_i > 1) for these elements ranges from 78.6% to 92.9%. Nevertheless, the overall pollution is mild: only one out of 28 sampling sites (3.6%) falls into the moderately polluted category. PMF resolved three major sources: (1) parent material plus evaporation enrichment (F, Mn, and Ba, ~45% of the total contribution); (2) agricultural and anthropogenic activities (As, Cr, V, Zn, ~40%); and (3) local industrial or waste inputs (Sn and Ba, ~15%). The XGBoost model shows good predictive performance on the test set (R² = 0.864, RMSE = 0.104). SHAP analysis reveals that Se, F, and As are the main drivers of the composite pollution index. Se has a clear threshold: once its concentration goes above 0.3 mg·kg⁻¹, its positive contribution jumps sharply. Overall, the farmland soils in Aksu show mild enrichment of several elements, with Se and F as the main indicators. Evaporation enrichment and farming practices are the dominant processes behind this enrichment. The integrated framework—pollution indices, PMF source apportionment, XGBoost prediction, and SHAP interpretation—provides a scientifically sound way to manage soil environments in arid regions. Full article

Catalytic ozonation has gained increasing attention as an advanced oxidation process (AOP) capable of overcoming some limitations of conventional ozonation in water treatment, particularly incomplete pollutant mineralization and the formation of undesirable by-products. This review provides a critical assessment of recent advances in heterogeneous catalytic ozonation, covering developments from microscale powdered catalysts to macrostructured supported systems. While research has predominantly focused on suspended microscale catalysts, a growing number of studies have investigated macrostructured materials due to their potential advantages for catalyst handling, recovery, and implementation in continuous-flow processes. The influence of catalyst composition, including metal oxides, carbon-based materials, and composite systems, on catalytic performance and stability is discussed. Although still an emerging research area, macrostructured catalysts have demonstrated promising characteristics that may facilitate catalyst recovery and continuous operation, making them attractive candidates for large-scale catalytic ozonation applications. The analysis also reveals important research gaps, particularly regarding long-term stability under continuous operation, scale-up studies, catalyst deactivation mechanisms, and the evaluation of real wastewater matrices. Future research should focus on developing robust, scalable catalytic systems that combine high activity, durability, and ease of recovery while meeting the requirements of sustainable and circular economy principles for advanced water treatment applications. Full article

The increasing generation of wood ash (WA) from biomass combustion presents both an environmental challenge and an opportunity for sustainable resource utilization. This review provides a comprehensive assessment of recent advances in the valorization of WA for the development of sustainable engineering materials within a circular economy framework. Unlike previous studies that primarily focus on isolated applications of WA, this work integrates multiple technical dimensions, including material characterization, advanced manufacturing technologies, mechanical performance evaluation, computational modelling, and industrial commercialization pathways. Wood ash typically exhibits alkaline characteristics (pH 9–13.5) and particle sizes ranging from 1 to 1000 µm, enabling its application in a wide range of material systems. In cementitious materials, partial replacement of cement with WA (0.10–20%) generally improves mechanical performance, whereas excessive incorporation may reduce structural integrity. The high silica content (>62%) in certain WA types also enables its utilization in lightweight glass systems and radiation-shielding materials. Furthermore, WA has emerged as a promising functional filler in polymeric and ceramic composites, where additions above 0.5% can enhance dynamic mechanical properties and thermal stability. The review also examines standardized inspection and testing procedures, including quality control (QC) and quality assurance (QA) frameworks based on American Society for Testing and Materials (ASTM), Canadian Standards Association (CSA), and European standards, to ensure the reliability of WA-derived materials. Recent developments in artificial intelligence, machine learning, and computational modelling are highlighted for predicting mechanical behavior, optimizing processing parameters, and enabling digitalized manufacturing systems. In addition, circular manufacturing strategies and economic evaluation models, including break-even analysis, are discussed to assess the industrial feasibility of WA-based products. By integrating circular economy principles with materials engineering, digital technologies, and economic assessment, this review establishes a holistic framework for transforming wood ash from an industrial residue into value-added sustainable materials for construction, energy, and advanced composite applications. Full article

Bamboo, a fast-growing and sustainable biomass, has traditionally been used in structural applications; however, its hierarchical architecture and rich chemical composition enable both the derivation of advanced nanomaterials and the fabrication of bamboo-assisted nanostructures. Recent studies demonstrate that such bamboo-based nanomaterials, including nanocellulose, lignin nanoparticles, silica nanoparticles, carbon dots, and carbon-based nanostructures, exhibit unique physicochemical properties suitable for biomedical applications. This review provides an overview of bamboo biology and classification, chemical composition, extraction and synthesis of bamboo-derived nanomaterials, and their biomedical applications. Emphasis is placed on their diverse biomedical applications, including drug delivery, tissue engineering and regenerative medicine, wound healing and antimicrobial dressings, cancer therapy, antioxidant and anti-inflammatory applications, and biomedical imaging and biosensing. In addition, emerging approaches that integrate bamboo-derived materials with plant-based bioactive compounds, particularly rose-derived phytochemicals, are proposed as promising strategies for achieving synergistic, broad-spectrum antibacterial activity against both Gram-positive and Gram-negative bacteria. Overall, bamboo-based nanomaterials offer a sustainable and versatile platform for next-generation nanomedicine, with significant potential for future biomedical innovations. Full article

The growing demand for sustainable, natural-based polymeric materials has accelerated research into cellulose-derived gels. Ethyl cellulose (EC) is a promising candidate; however, its high brittleness, limited flexibility, and insufficient water barrier properties often require the use of a plasticizer to improve its performance. In this study, we synthesized hydroxylated linseed oil polyol (LPO) and evaluated its performance as a bio-based plasticizer for EC-derived dried gels. LPO was characterized by ¹H NMR, ¹³C NMR and FTIR. In addition, quantitative tests further confirmed high hydroxyl value of 280.36 ± 28.96 mg KOH/g. Incorporating LPO into the EC organogel matrix improved the functional performance of dried gel composites, including their mechanical, water vapor barrier, thermal, and morphological properties. The greatest plasticizing performance was achieved at the highest concentration investigated (30% w/w), with a fivefold increase in elongation at break compared to the pristine EC, together with the lowest WVP value (~13 g·mm·m⁻²·kPa⁻¹·day⁻¹), while maintaining good thermal stability and a smooth, homogeneous surface morphology. In addition, FTIR, SEM, and accelerated aging analyses supported the good compatibility and stability of the EC/LPO system. These effects are attributed to intermolecular interactions between EC chains and LPO. Overall, LPO is demonstrated to be an effective bio-based plasticizer for advancing sustainable bioplastic materials, highlighting its potential to replace conventional plasticizers. Full article

This work reports, for the first time, the use of agave bagasse from “Tequila Weber Var” as an efficient and eco-friendly template for the microwave-assisted solvothermal synthesis of C@TiO₂ photoelectrodes. The characterization of the C@TiO₂ materials was performed using composition and elemental analysis, diffuse reflectance/UV-visible spectroscopy, N₂ adsorption/desorption isotherms, scanning and transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction patterns, cyclic voltammetry, impedance spectroscopy, and variations of the open-circuit potential in a conventional electrochemical cell. Three 1:1, 4:1, and 8:1 agave:Ti volume ratios were used to explore the influence of carbon content upon the optical and photoelectric properties of TiO₂. The composite with a 1:1 ratio showed a charge transfer kinetic capacity of 0.86 C·cm⁻²·s⁻¹ with the highest current density flow of 2.2 mA·cm⁻², and the lowest optical band gap (E_bg) value of 2.92 eV, boosting the optoelectronic behavior of TiO₂. The photoanode composed of FTO/C@TiO₂ with the hybrid material with a 1:1 ratio was preliminarily evaluated in a photovoltaic solar cell, showing a light-to-electricity conversion efficiency higher than the other two composites and up to 12.5 times higher than the photoanode only composed of neat TiO₂. The present results contribute to the state-of-the-art of eco-friendly organic–inorganic thin film photoelectrodes for the sustainable synthesis of third-generation solar cells using bagasse-derived waste as an efficient carbon source for the synthesis of hybrid photoactive semiconductors. Full article

Aquaponics is an integrated and resource-efficient production system that combines aquaculture and hydroponics in a closed-loop environment with reduced water consumption and nutrient losses. The present study evaluated the nutritional composition, mineral profile, microbiological quality, and antioxidant-related phytochemical characteristics of red amaranth (Amaranthus cruentus L.) cultivated in a recirculating aquaponic system under controlled environmental conditions. Leaf biomass was analyzed for proximate composition, macro- and micronutrient content, total phenolic and flavonoid compounds, betalains, chlorophyll pigments, and antioxidant activity using standard analytical and spectrophotometric methods. The results demonstrated high crude protein content and substantial accumulation of essential minerals, particularly calcium, potassium, and magnesium. The analyzed biomass also exhibited elevated levels of phenolic compounds, flavonoids, betalains, and chlorophyll pigments associated with considerable antioxidant potential. The pigment profile suggested good physiological adaptation of plants to aquaponic cultivation conditions. In addition, microbiological analysis confirmed acceptable hygienic quality and safety of the harvested plant material. Overall, the findings indicate that red amaranth can be successfully cultivated in aquaponic systems while maintaining high nutritional value and functional food potential. The study highlights aquaponic cultivation as a sustainable approach to producing nutrient-dense leafy vegetables within environmentally responsible agricultural systems. Full article

The transition towards sustainable aluminum manufacturing is commonly assessed through recycling rates, energy savings, and resource efficiency, but its distributive effects across global value chains remain insufficiently examined. This study evaluates whether recycled aluminum value chains contribute to both circularity and north–south redistribution, or whether they reproduce unequal patterns of value capture, industrial upgrading, employment quality, and trade dependency. The analysis combines UN Comtrade trade data for HS 7601–7616, OECD ICIO 2025 value added indicators, ILOSTAT labor statistics, and UN SDG data for the 2018–2020 three-year average. Eighty economies are classified into four groups: advanced industrial economies, emerging industrial economies, lower-middle-income economies, and low-income economies. A composite indicator linked to SDGs 8, 9, 10, and 12, with SDG 17 incorporated only as a trade dependency context, is constructed from normalized industrial, circular material flow, distributive, and job-quality variables. The results show a clear north–south hierarchy: advanced economies concentrate a larger share of exports in aluminum manufactures, while low-income economies remain more dependent on scrap flows. Group A captures most chain value added, whereas Groups C and D retain only marginal shares. Labor productivity falls sharply from advanced to low-income economies, while working poverty increases substantially. By contrast, circularity scores vary less strongly across groups, suggesting that participation in circular material flows does not necessarily imply equitable industrial upgrading. This study shows that circularity in recycled aluminum value chains does not automatically generate redistribution and provides a replicable framework for distinguishing material circularity from distributive justice. Full article

The skin is the largest organ of the human body and, due to its direct contact with the external environment, is one of the most vulnerable tissues. Traditional medical bandages and gauze exhibit limited efficacy in wound management, often neglecting the control of wound inflammation and the promotion of skin regeneration. Hydrogels, as an emerging material, possess appropriate swelling capacity, oxygen permeability, and the ability to absorb wound exudates, thereby facilitating wound healing, making them an ideal choice for functional applications in skin tissue engineering. In this study, dual-treated balsa wood (BWSM) was used as the hydrogel substrate, with polyvinyl alcohol (PVA), chitosan (CS), and zinc gluconate (ZnG) used as the primary raw materials. The BWSM/PVA/CS/ZnG hydrogel was prepared via gamma-ray irradiation. Balsa wood treated with alkaline solutions, hydrogen peroxide solutions, and microwave treatment processing exhibited enhanced transparency, increased porosity, improved thermal stability and swelling rates, while retaining adequate mechanical strength. Gamma-ray irradiation of the BWSM/PVA/CS/ZnG hydrogel wound dressing demonstrated sustained drug release and antibacterial efficacy through release and antimicrobial tests. Animal experiments showed that the BWSM/PVA/CS/ZnG composite hydrogel promoted wound healing in mice and effectively prevented scar formation. The aforementioned results demonstrate that the PVA/CS/ZnG composite hydrogel loaded with balsa wood exhibits durable antibacterial properties and high mechanical strength and promotes wound healing, making it suitable for applications in biomedical materials such as wound dressings. Full article

Background: Conventional ophthalmic eye drops have low bioavailability (<5%) and poor patient adherence, driving the development of sustained-release ophthalmic drug delivery systems. The lacrimal drainage system represents a unique anatomical site for minimally invasive depot formulations. Objective: To summarize and critically appraise punctal and intracanalicular drug delivery systems, occlusive devices, and in situ-forming hydrogels with respect to composition, release mechanisms, clinical efficacy, safety, and critical quality attributes (CQAs). Methods: A narrative literature review was conducted using PubMed, Scopus, Web of Science, Google Scholar, ClinicalTrials.gov, and patent/regulatory sources, including FDA materials and Google Patents, covering 2001–2026. Anatomical features, materials, active pharmaceutical ingredients, release profiles, and adverse events were analyzed. Results: Seventy-one sources were included. Occlusive plugs without an active pharmaceutical ingredient demonstrate premature expulsion in up to 57.4% of cases and bacterial colonization in 44%. Drug delivery systems provide release from 7 days (PEGDA hydrogels) to 3 months (Eximore, Ocular Therapeutix™). DEXTENZA^® (dexamethasone) is FDA-approved for postoperative inflammation, whereas pivotal trials of travoprost (OTX-TP) and latanoprost systems (L-PPDS, EXP-LP) did not demonstrate superiority over placebo or eye drops. In situ systems eliminate size-fitting requirements but face challenges related to gelation control and biodegradation. Conclusions: We propose the following candidate CQAs: retention (>80% over 4 weeks), swelling degree (30–60%), controlled burst release (<40% within 24 h), and mechanical compatibility. The proposed QTPP matrices for punctal, intracanalicular, and in situ systems may guide the development of ophthalmic drug delivery platforms. Full article