Search Results (2,314)

The valorization of agricultural and food industry residues represents an important component of the circular bioeconomy, enabling the conversion of waste streams into value-added materials while mitigating environmental pollution. Spent coffee grounds (SCGs), a solid by-product generated during the extraction of coffee beans with hot water or steam, constitute an abundant lignocellulosic biomass residue. Due to their physicochemical properties, SCGs can be used as low-cost adsorbent materials for the treatment of metal-contaminated wastewater, offering a sustainable alternative to traditional synthetic resins. This review summarizes recent research on the application of SCGs for the removal of metal ions from aqueous systems. The adsorption performance of raw and modified SCGs, including materials obtained via carbonization and chemical functionalization, is comparatively evaluated. Furthermore, key operational parameters governing the adsorption process and the corresponding metal removal efficiencies are discussed. Full article

Metallurgical-grade silicon (MG-Si) is an important source material for many industrial applications, including the manufacture of alloys, solar photovoltaics, and electronics. The process to refine raw materials into MG-Si is energy-intensive, with the predominant method of submerged-arc furnaces requiring energy consumption of approximately 11–13 kWh/kg Si. Recent research has discussed promising methods for reducing the energy required for the silicon production process, including the use of molten-salt electrolysis (MSE), a technique that offers potential savings in energy consumption without requiring carbon inputs for the process. This paper presents a techno-economic study of a potential industrial-scale MSE plant for MG-Si production to evaluate the trade-offs between capital and operating costs of the system. Capital costs are sourced from recent MG-Si plants and an existing cost model developed for MSE processes that includes the size of the plant and the operating temperature among its inputs. The results show that MSE technology has the potential to be an economically cost-competitive option for MG-Si production if the technology successfully scales to industrial production and matures enough to allow for financing costs similar to that of a comparably sized submerged-arc furnace plant. Full article

Four sweet cherry cultivars (FuChen, Redlight, Huangmi, and Samituo) grown in northern China were used to produce sweet cherry wines with two alcohol levels. Physicochemical properties, antioxidant capacity, and volatile aroma compounds of the wines were systematically investigated. The results showed that wine from the Redlight cultivar with an alcohol content of 11.22 ± 0.17% contained the highest phenolic content and also exhibited the strongest antioxidant capacity as measured by DPPH and ABTS•⁺ assays. Meanwhile, wine from the FuChen cultivar with an alcohol content of 11.45 ± 0.03% had the highest anthocyanin content and showed the strongest FRAP antioxidant activity. Orthogonal partial least squares discriminant analysis (OPLS-DA) based on electronic nose data clearly distinguished the eight sweet cherry wine samples from different cultivars. A total of 58 volatile compounds were identified by headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS). Both principal component analysis (PCA) and OPLS-DA revealed clear differences among the sweet cherry wines based on their volatile composition. Using variable importance in projection (VIP) scores > 1 and relative odor activity values (ROAVs), the key aroma compounds contributing to the characteristic aroma profiles of the eight sweet cherry wines were identified as ethyl butanoate, isoamyl acetate, isoamyl hexanoate, methyl decanoate, ethyl decanoate, ethyl benzoate, methyl salicylate, citronellol, and eugenol. These findings provide important guidance for the selection of raw materials to improve the production of sweet cherry wines with targeted alcohol levels. Full article

This study investigated the anti-inflammatory material basis and quality control of Pinellia ternata (P. ternata) to provide a modern scientific interpretation for its therapeutic properties. First, ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS/MS) analysis was used to analyze different polar fractions of P. ternata, resulting in the identification of 79 compounds. Next, an in vitro evaluation using an LPS-induced RAW264.7 cell inflammation model revealed that the ethyl acetate fraction exhibited the most significant inhibition of nitric oxide (NO) production. Three cyclodipeptides, cyclo (Pro-Leu), cyclo (Phe-Pro), and cyclo (Leu-Phe), which displayed notable differences from other fractions, were subsequently screened. Molecular docking studies showed binding free energies below −5 kcal/mol with inducible nitric oxide synthase (iNOS), indicating potential anti-inflammatory targeting properties. Cellular experiments further confirmed that the reduction in NO production induced by these cyclodipeptides ranged from 11.03% to 40.38%. To enable their simultaneous quantification, a method based on ultra-high-performance liquid chromatography–triple quadrupole tandem mass spectrometry (UHPLC-QQQ-MS/MS) in the multiple reaction monitoring (MRM) mode was established, meeting all analytical validation criteria. Application of this method to P. ternata samples from different origins and growth conditions demonstrated that the contents of these cyclodipeptides were significantly influenced by both the origin and cultivation method. In conclusion, this study preliminarily identifies cyclodipeptides as an important anti-inflammatory material basis of P. ternata, and the established quantitative method provides methodological support and data for constructing its quality evaluation system. Full article

Reducing and managing emissions of mine waters and the minerals dissolved in them, and above all, using these wastes as resources, is an important element of sustainable development in regions undergoing a gradual phase-out of fossil fuel extraction. This article examines selected aspects of mine water management and the mineral substances contained therein, using the Polish hard coal mining industry as a case study, providing valuable insights for both Poland and other mining regions reducing raw material extraction regarding the sustainability of social water demand, mining sector restructuring, and Sustainable Development Goals (SDGs). In Poland, underground hard coal mining remains a significant source of mine water and mineral salt emissions. Mine waters, discharged into the catchments of major rivers (approximately 200 million m³ per year) along with their dissolved mineral compounds (approximately 1.5 million Mg per year), have repeatedly contributed to serious environmental disruptions, e.g., the phenomena of so-called “fish kill”. This study analyzes both the scale of emissions and the economic utilization of mineralized mine waters discharged to the surface by underground hard coal mining in Poland. Key processes and potential causes for the observed increase in environmental burdens are discussed. Furthermore, the paper presents a current statistical assessment of the trends and scale of emission changes, which can serve as a basis for environmental management decision-making amidst the decarbonization of the economy. Utilizing potential water resources and mineral compounds from mine waters for internal use or within circular economy applications can reduce environmental pressure, support compliance with sustainable development policies, and mitigate long-term impacts on post-mining regions. Full article

The European Union aims to achieve climate neutrality by 2050, with biogas and biomethane expected to play an increasingly important role in the decarbonisation of the energy system. This study investigates the economic and social determinants shaping the development of biogas production in European countries and identifies an optimal investment strategy for new biogas plants under varying environmental conditions. An expert–mathematical method was applied to assess and hierarchise twenty economic and social factors influencing biogas production, based on evaluations provided by 71 experts from eleven European countries. Subsequently, individual choice criteria derived from game theory were used to determine the optimal strategy for biogas plant construction under conditions of uncertainty. The results indicate that six determinants—EU-level production support mechanisms, investment costs, national support instruments, process efficiency improvements, community involvement, and agricultural raw material prices—account for 52.9% of the total impact on biogas development potential. Among the analysed investment options, large-scale biogas plants with an installed capacity of 3 MW were identified as the optimal strategy, offering the lowest unit production costs and the lowest risk of cost overruns across diverse economic and social environments. These findings provide policy-relevant insights for supporting efficient and socially acceptable biogas deployment in Europe. Full article

Construction industry remains a major driver of global resource use and waste generation, therefore, identifying sustainable material alternatives is increasingly important. Recycled-textile-based insulation presents a promising pathway to support circular economy principles by diverting post-consumer waste from landfills and reducing reliance on virgin petrochemical materials. This study conducts a cradle-to-gate life cycle assessment (LCA) using SimaPro to compare polyurethane (PU) foam and recycled denim (cotton fiber) insulation. The system boundary includes raw material extraction, transportation, and manufacturing. A functional unit of 1 m² of installed insulation with a thermal resistance of RSI = 1 m²·K/W at the factory gate ensures comparability, with mass-based results reported as secondary metrics. The results indicate that recycled denim exhibits higher embodied carbon per unit mass, despite lower production energy and lower cradle-to-gate impacts per installed area, reinforcing the need for a declared-unit-based comparison tied to thermal performance. Air leakage is evaluated separately as a complementary performance indicator influencing in-service energy behavior showing significantly lower air leakage for PU; but is not included in the cradle-to-gate normalization. However, it could be argued that materials with improved airtightness may enable the use of reduced insulation thickness while still achieving equivalent performance, thereby potentially lowering overall material demand. Nevertheless, recycled denim offers environmental advantages by reducing landfill waste and promoting resource conservation through material reuse. A transient coupled heat–moisture model in COMSOL Multiphysics, using climate data from Arizona and Florida, further reveals that denim absorbs more moisture than polyurethane. This leads to larger heat flux fluctuations, highlighting a trade-off between denim’s sustainability advantages and its reduced hygrothermal durability. Overall, these findings demonstrate the limitations of single-metric comparisons and emphasize the need for performance-based, multi-criteria assessments that integrate functional efficiency with circularity. Future research should incorporate occupant health and comfort to enable a more comprehensive evaluation of insulation sustainability. Full article

Background/Objectives: Citrus peels are widely utilized as functional ingredients in health foods; however, their functional value is often assumed based on botanical classification rather than verified chemical composition. Bushukan (Citrus medica var. sarcodactylis) was selected as it lacks developed edible pulp; consequently, the usable portion consists almost entirely of peel tissue, making it a suitable model for evaluating peel-specific functional components. This commentary highlights the importance of species- and origin-specific evaluation through a case study of Bushukan (Citrus medica var. sarcodactylis) whole fruit powder cultivated in Japan. Methods: Dried whole-fruit powder samples of bushukan, prepared by freeze-drying and hot-air drying at 50 °C, were analyzed, and the contents of hesperidin and nobiletin were quantified using high-performance liquid chromatography (HPLC) following methanol reflux extraction. Results: Hesperidin was detected at 75 mg/100 g under both drying conditions, whereas nobiletin was below the practical limit of quantification (approximately 1 mg/100 g). No reduction in hesperidin content was observed after drying at 50 °C. These levels were markedly lower than those reported for commonly used citrus peels, such as satsuma mandarin, in previous studies. Conclusions: This commentary demonstrates that Japanese-grown bushukan samples do not necessarily provide substantial levels of commonly expected citrus flavonoids. These findings underscore the need for species- and origin-specific compositional verification before the use of citrus peels as raw materials for health food applications, illustrating this need through a practical, cautionary case study. Full article

This study examines the impact of agribusiness corporations (large-scale agricultural enterprises) and family farms on the sustainable development of agriculture and rural areas in Ukraine, and considers implications for SDG-aligned agri-food value chains that rely on stable access to sustainably produced raw materials. The research applies a multi-criteria decision analysis framework integrating economic, environmental and social indicators at the regional level. Using min–max normalisation, scoring and ranking methods, composite indices of economic sustainability, environmental sustainability, and sustainable rural development were constructed for 20 selected Ukrainian regions, and an integral sustainability index was calculated. Spearman’s rank correlation was applied to identify relationships between sustainability indicators and the structural characteristics of agricultural production. The results reveal pronounced interregional differentiation and an overall predominance of economic over environmental sustainability. Regions with a higher share of family farming demonstrate stronger environmental sustainability and more balanced development patterns, whereas dominance of large-scale enterprises is associated with adverse environmental effects. At the same time, relationships between farm structure and sustainable rural development are weak and not statistically significant, suggesting that social sustainability outcomes depend on more complex and context-dependent mechanisms beyond production scale alone. The findings highlight structural trade-offs between economic efficiency and environmental sustainability and underline the importance of regionally differentiated policy instruments. Strengthening support for family farms is identified as a promising mechanism for improving environmental performance and enhancing upstream conditions for sustainability-oriented sourcing and agri-food value chains. Full article

Ti₂AlC, an important member of the MAX phase family, exhibits combined metallic and ceramic characteristics, showing potential for applications in conductive composites and high-temperature structural components. However, this phase possesses a narrow thermodynamic stability window, making high-purity synthesis challenging. Conventional solid-state synthesis requires temperatures exceeding 1300 °C, where aluminum volatilization and kinetic limitations of carbon diffusion lead to impurity phases such as TiC and Ti₃AlC₂. Based on the ionic transport characteristics of molten salt media, this study employed the eutectic NaCl-KCl molten salt method to synthesize Ti₂AlC using Ti, Al, and TiC powders within the temperature range of 1000–1150 °C. Systematic investigations revealed that an optimized raw powder composition (Ti:Al:TiC = 1:1.10:0.95) at 1100 °C yielded Ti₂AlC powders with 96.1% phase purity, high crystallinity, and typical laminated structure with stable stoichiometry (Ti/Al ≈ 2:1). Furthermore, Ag/Ti₂AlC composites demonstrated excellent electrical conductivity (resistivity of 5.72 μΩ·cm) and favorable mechanical properties, validating the applicability of this synthetic route for conductive composite materials. Full article

Alkali-activated solid waste-based geopolymer represents a novel form of inorganic cementitious material, which is one of the key research directions in the building materials field to achieve the targets of carbon peak and carbon neutrality. Therefore, taking solid waste materials as raw materials to prepare the alkali-activated solid waste-based geopolymers with better mechanical properties is of significant importance for expanding the utilization channels of industrial solid waste materials in Hebei Province. In this study, three solid waste materials, slag, iron tailings sand and coal gangue powder, were used as the precursors of geopolymer, and solid sodium silicate was used as the activator to prepare the solid waste-based geopolymer. Response surface methodology was adopted to design the composition of the geopolymer, and the dosages of slag, Na₂O and coal gangue powder were taken as design variables, and the compressive strength of the geopolymer at 7 days and 28 days were taken as response variables. The results show that it is feasible to optimize the composition of solid sodium silicate-activated solid waste-based geopolymer (SSG) by using response surface methodology. The error value of the SSG-mortar compressive strength prediction model is below 2.0%. The slag contents exhibit a positive correlation with the compressive strength of SSG-mortar, but the coal gangue powder contents and Na₂O contents have a negative correlation. The optimized compositions of SSG-mortar are 20% iron tailings sand, 26% coal gangue powder, 54% slag, and 6.41% Na₂O (regulated by 6.23% solid sodium silicate and 6.23% solid NaOH granules), and the corresponding compressive strengths of SSG-mortar at 7 days and 28 days are 37.1 MPa and 44.9 MPa, respectively. In addition, dry shrinkage tests, wet–dry cycling tests, freeze–thaw cycling tests, salt corrosion tests, SEM analysis and XRD analysis were conducted on the SSG-mortar with the optimal composition to evaluate its shrinkage behavior, freeze–thaw resistance, salt corrosion resistance and microstructural strengthening mechanisms. The results show that SSG-mortar has relatively good frost resistance and salt erosion resistance. The mass loss rate value and compressive strength loss rate value of SSG-mortar are 1.67% and 18.7%, respectively, after 100 freeze–thaw cycles. Furthermore, the corrosion resistance coefficient value of SSG-mortar is greater than 92%, and the mass loss rate value is lower than 2.4%. The SEM and XRD test results display that, in an alkaline environment, the interwoven consolidation of hydrated gels (including C-S-H gel, C-A-S-H gel, C-(N)-A-S-H gel and N-A-S-H gel) and the filling effect of solid wastes jointly achieve an improvement in the properties of SSG-mortar. Full article

The effective utilization and effective valorization of various organic industrial wastes have become increasingly important issues. One significant area for enhancing the circular economy is the processing of waste generated from vegetable oils and animal fats. This article focuses on the processing and use of soapstocks, which result from the chemical reaction between fatty acids and alkali. These soapstocks represent the most significant portion (approximately 70–90 wt% by weight) of waste produced by the oil and fat industry. The raw material for this study was soapstock obtained from the neutralization of sunflower oil at the PJSC “Zaporizhzhya Oil and Fat Plant,” designed by the Belgian company “De Smet.” The soapstock yield was found to be 9.95 wt% based on 100 wt% oil. Through a series of treatments involving water, acid, and multiple washes, a low-sulfur fuel component was produced that nearly meets the standards for boiler fuels as outlined in DSTU 4058-2001 and PN-C-96024:2020, except for the heat of combustion. It fully complies with the requirements specified in ISO 8217:2024. The sulfur content of the final product was determined to be 0.12 wt%. Additionally, the fuels produced contained 75.33 wt% carbon, 11.64 wt% hydrogen, and 12.00 wt% oxygen. Due to the relatively low oxygen content, the resulting product exhibits approximately twice the heat of combustion of similar fuels derived from other waste streams in the oil and fat industry. Full article

Biological reactions are widely applied in processes such as bioenergy production, raw material manufacturing, and resource recovery from waste. As a main reactor type, the stirred-tank bioreactor exhibits prominent advantages of high mixing efficiency and strong adaptability. At present, the optimization of bioreactors mainly focuses on rigid impellers, and the research on flexible impellers is insufficient. Identifying the influence of flexible materials on bioreactor performance is of great significance. In this work, a stirred-tank bioreactor equipped with flexible blades was designed. In addition, a performance detection method coupling Particle Image Velocimetry (PIV) and image recognition was proposed to systematically study the effects of stirring speed, liquid environment, and impeller type. The results indicated that compared with rigid impellers, flexible impellers could reduce 7.7% low-velocity zones and save 15% mixing time. Velocity could be distributed more uniformly, and the suitable velocity ratio was increased by 7.88%. Moreover, the power consumption had been reduced by 7.49%. Taking into account the mixing efficiency and the impact of shear stress, the optimized structural combination and operating parameters were a pitched blade turbine (PBT)-propeller impeller type and a stirring speed of 300 rpm. This work provides important references for the design and optimization of stirred-tank bioreactors. Full article

Currently, the production methods for L-threonine (L-Thr) mainly include chemical synthesis, protein hydrolysis, and microbial fermentation. Among these, microbial fermentation has become an important method for the industrial production of L-Thr, owing to its advantages of abundant raw material sources, environmental friendliness, and high product purity. In recent years, gene editing, synthetic biology, and artificial intelligence have been integrated to significantly improve the synthesis efficiency and production stability of L-Thr and its derivatives through the rational design of metabolic networks, dynamic regulation of fermentation processes, and intelligent optimization of strain performance. This review systematically summarizes the progress of research on the biosynthesis of L-Thr and its derivatives, with emphasis on elucidating synthetic pathway regulation methods based on genetic engineering and metabolic engineering strategies, and summarizes the latest research developments in the synthesis of its derivatives, aiming to provide systematic references for efficient biomanufacturing in this field. Full article

Active suspensions in automotive applications are designed to improve vehicle stability and comfort and reduce vibration transmission from the road surface. Active systems often include a dedicated actuator, and, to reduce their mass and energy absorption, it is a typical choice to rely on brushless electric motors with permanent magnets containing Critical Raw Materials such as Neodymium, a Rare Earth Element (REE), offering favorable power density values. Although these systems offer clear advantages in terms of ride quality and performance, their direct and indirect energy requirements, combined with their dependence on resource-intensive materials, raise concerns about life cycle sustainability: in other words, there is a trade-off between production impact (relevant for REE) and use impact (reduced by REE adoption). To address this issue, the research proposes a method to estimate energy consumption during the use phase of a vehicle through a dedicated parametric modeling and simulation framework; the aim is to evaluate the energy performance of active suspension systems under different road and driving conditions. The analysis explores how design parameters and operational choices affect energy consumption and efficiency. The simulation results reveal a marked sensitivity of system performance to road profiles and driving scenarios, highlighting the importance of holistic assessments during the early stages of design. The proposed framework represents a first step toward integrating circular design principles into the development of active suspensions. By combining technical and environmental perspectives, it supports the development of next-generation automotive components that balance comfort, performance, and sustainability. Full article