Search Results (1,278)

Lead (Pb²⁺) pollution poses a severe threat to the ecological environment and human health due to its high toxicity, bioaccumulation, and refractory nature. Traditional treatment technologies for lead-contaminated wastewater, such as chemical precipitation, ion exchange, and membrane separation, often face limitations, including secondary pollution, high costs, and high energy consumption. In contrast, adsorption has emerged as a promising alternative technology with advantages such as a simple process, high efficiency at low concentrations, and renewability. Biomass-based hydrogels and their composite systems, as novel green adsorbent materials, combine the abundant functional groups of natural biomass with the structural stability, high porosity, and recoverability of hydrogels through a three-dimensional cross-linked network, offering unique advantages for lead ion adsorption. Depending on their composition, these systems range from fully biodegradable pure biopolymer networks to partly biodegradable or biomass-containing composites incorporating inorganic, carbon-based, or metal–organic framework (MOF) materials. This paper systematically reviews the latest research progress on cellulose, lignin, sodium alginate, chitosan, starch-based hydrogels, and their composite systems for lead (Pb²⁺) adsorption. First, the structural characteristics, cross-linking mechanisms, and functional modification strategies of various biomass hydrogels are introduced. Then, the adsorption mechanisms of Pb²⁺, including multiple modes of action such as coordination complexation, ion exchange, electrostatic interaction, and physical adsorption, are systematically analyzed. The adsorption performance of different material systems is compared in detail. The regeneration and recycling performance, as well as the potential practical applications, of the materials are evaluated. On this basis, the main challenges in current research are summarised: balancing adsorption capacity and mechanical strength, achieving selective adsorption in actual wastewater, improving regeneration efficiency, and optimizing costs. In addition, future development directions for biomass hydrogel adsorbent materials are discussed, including the design of multi-functional composite materials, the development of intelligent, responsive hydrogels, engineering-scale-up, and life-cycle assessment. This review aims to provide a theoretical framework and technical roadmap for the rational design of high-performance, sustainable hydrogel adsorbents and to promote their engineering application for the treatment of lead-contaminated wastewater. Full article

This study aimed to screen for optimal Traditional Chinese medicine (TCM) combinations and subsequently optimize their extraction processes for developing antibacterial dressings by preparing aqueous and hydroethanolic extracts from Herba Centellae asiaticae, Flos Calendulae, Folium Aloe, Cortex Betulae and Rhizoma Curcumae longae and evaluating their inhibitory activity against E. coli, S. aureus, C. albicans, and T-Salmonella using an agar diffusion assay. Synergistic combinations were identified through a grid screening method, with extraction processes optimized via single-factor experiments and Box–Behnken response surface design. The results demonstrated that the Folium Aloe and Cortex Betulae formulation exhibited the strongest synergistic antibacterial activity, with the inhibition zone expanding from 11.1/12.8 mm for individual components to 17 mm after combination, representing an increase of 21–36%. Single-factor and response surface optimization identified optimal process parameters as a ratio of 1.53:1, a hydroethanolic concentration of 79.5%, and an extraction time of 2.6 h, with a model R² value ranging from 0.9265 to 0.9783; the MIC values were reduced by 25–68.75%. The UPLC-QTOF-MS analysis of the optimized extract identified nine major constituents, including anthraquinones, chromones, and triterpenoids, providing the phytochemical basis for the observed bioactivities. Mechanistic studies via UV-Vis spectrophotometry and propidium iodide (PI) staining confirmed membrane disruption through nucleic acid and protein leakage. Cytocompatibility evaluation using L929 fibroblasts demonstrated >90% cell viability even at 1000 μg/mL. Additionally, the optimized extract exhibited concentration-dependent antibacterial activity, achieving a DPPH scavenging rate of 90% at 1.0 mg/mL, whereas its ABTS scavenging rate was comparable to that of ascorbic acid. The Folium Aloe and Cortex Betulae pair demonstrates dual antibacterial and antioxidant activities, providing an experimental basis for developing functional wound dressings and green antibacterial biomaterials. Full article

Fish processing by-products represent a valuable and sustainable source of collagen for biomedical and functional applications. In the present study, collagen was extracted from the scales of red mullet (Mullus barbatus), gilthead sea bream (Sparus aurata), and European sea bass (Dicentrarchus labrax) using a green extraction approach based on a natural deep eutectic solvent (NADES) system composed of citric acid, xylitol, and water. The extracted collagens were comprehensively characterized by SDS-PAGE, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses. The results confirmed the presence of Type I collagen and demonstrated that the characteristic triple-helical structure and molecular organization were preserved throughout the extraction process. To preliminarily evaluate their potential as matrices for incorporating bioactive compounds, collagen matrices were combined with Zingiber officinale (ginger) extract at different ratios. The resulting combinations were evaluated for antioxidant, antimicrobial, and cytocompatibility properties. Antioxidant activity increased significantly with increasing ginger concentration, with the highest radical scavenging activity observed in combinations containing the greatest proportion of ginger extract. Similarly, antimicrobial activity against Escherichia coli and Staphylococcus aureus was enhanced by ginger incorporation, with stronger inhibition observed against the Gram-positive bacterium. Cytocompatibility studies performed on human dermal fibroblast (HDFa) cells revealed that selected collagen–ginger combinations maintained high cell viability and did not induce substantial membrane damage, nuclear abnormalities, apoptosis, or necrosis at appropriate concentrations. Overall, the findings demonstrate that fish scale-derived collagen obtained through a sustainable NADES-based extraction process possesses favorable structural and biological properties and may serve as a potential carrier matrix for plant-derived bioactive compounds. These findings provide preliminary evidence supporting the future development of environmentally friendly functional biomaterials with prospective applications in pharmaceutical, biomedical, and tissue engineering fields. Full article

Proton Exchange Membrane Fuel Cells (PEMFCs) have emerged as promising clean-energy-conversion devices for various applications, including transportation and stationary power generation. The accurate modeling and parameter estimation of PEMFCs are fundamental to optimizing their performance, extending their operational lifespan, and facilitating their widespread commercialization. However, their inherent nonlinear characteristics and complex electrochemical processes present significant challenges in developing accurate mathematical models and reliable parameter-estimation methods. This review systematically examines the state of the art in PEMFC parameter estimation and modeling, with particular emphasis on the critical challenges posed by nonlinearities, the evolution of analytical and computational methods, and the role of sensitivity analysis in model refinement. The paper synthesizes findings from recent studies employing evolutionary algorithms, metaheuristic techniques, reinforcement learning, and hybrid approaches, evaluating their relative merits in terms of accuracy, convergence speed, and robustness. Furthermore, it explores how sensitivity analysis provides valuable insights into parameter influence under varying operational conditions, guiding model optimization efforts. The review identifies persistent gaps in current methodologies, particularly regarding generalizability across different fuel cell types and real-time applicability, while highlighting promising directions for future research, including hybrid algorithms and advanced data-preprocessing techniques. Full article

The olive oil industry generates large amounts of by-products, particularly olive pomace and olive mill wastewater, which represent valuable sources of polyphenolic compounds with well-recognized antioxidant, anti-inflammatory, antimicrobial, and health-promoting properties. Within the framework of the circular economy, the valorization of these olive-derived residues has emerged as a promising strategy for converting low-value waste into high-added-value ingredients for food, pharmaceutical, and cosmetic applications. This review provides a comprehensive overview of recent advances in sustainable extraction and sample preparation approaches for the recovery of olive polyphenols, including ultrasound-, microwave-, enzyme-, and membrane-assisted technologies, as well as the use of green solvents and environmentally friendly extraction systems. Furthermore, the review discusses advanced analytical strategies for the identification and quantification of olive-derived polyphenols, covering chromatographic, spectrometric, electrophoretic, and miniaturized analytical platforms. Special attention is given to biopolymer-based encapsulation systems developed to enhance stability, controlled release, bioaccessibility, and bioavailability of these bioactive compounds. Finally, current challenges and future perspectives regarding the integration of green extraction technologies, analytical methodologies, and advanced delivery systems are highlighted to promote the sustainable exploitation of olive by-products within a circular economy framework. Full article

The fading of painted relics is a widespread deterioration phenomenon in ancient painted cultural relics, yet its underlying mechanism has long been attributed solely to pigment oxidation. Directed at colored drawings with complex surface microstructures, such as pottery paintings, wall murals and architectural paintings, here we challenge this view by demonstrating that light scattering induced by sub-micron pores within the paint layer plays a dominant role, especially Mie scattering when pore sizes approach visible light wavelengths (400–700 nm). In order to minimize the damage to the genuine painted relics, a large number of simulated experiments were conducted first. Using porous polyacrylamide (PAM) membranes and nylon 6 filter membranes as model systems, we show that pore-induced scattering reduces the optical path length for light absorption, leading to a significant decrease in color saturation and brightness. By filling the pores with non-volatile colorless ionic liquids ([BMIM]PF₆) (n = 1.41) or glycerol (n = 1.47)—both possessing refractive indices close to those of the pigments—the scattering is effectively suppressed, and the original color is restored. The filling treatment reduces the color difference (ΔE*ab) by 30%–50% and the surface reflectivity by 20%–40%. Mercury intrusion porosimetry and fluorescence spectroscopy confirm that pore elimination and optical path lengthening are responsible for the color recovery. The proposed mechanism and restoration strategy were successfully validated on authentic painted brick fragments from the Western Qing Tombs (Hebei, China), where severely faded green and red patterns reappeared after ionic liquid treatment. This study provides a new interface-regulation paradigm for the conservation of painted cultural heritage, shifting the focus from irreversible chemical remediation to reversible physical restoration and offers a generalizable platform for controlling light scattering in porous optical materials. Full article

This study presents a mathematics-based simulation model for designing, analyzing, and optimizing offshore green hydrogen stations powered by solar photovoltaic systems, applicable to any location worldwide. Developed in Python, the model integrates environmental, physical, and technological parameters to simulate and forecast hydrogen production via water electrolysis using alkaline (ALK) or proton exchange membrane (PEM) electrolyzers, combined with an adiabatic compressor that enhances energy storage and facilitates integration into smart grids. The five-phase modular methodology includes timeframe definition; estimation of solar electricity generation based on solar trajectory and the geographic orientation of photovoltaic panels; performance modeling of electrolyzers and compressors; and the integration of all components into a cohesive system. A case study demonstrates the model’s real-world applicability. Results from the Gulf of Cadiz case study show a substantial increase in solar energy capture in offshore environments due to reduced atmospheric pollution and sea-surface reflection. The reflected component is modeled as a function of sea-surface flatness. This reflection increases the daily average solar irradiance received by the photovoltaic panels by 8.44%. Under the modeled 2026 conditions and equivalent irradiance levels, the ALK electrolyzer produces 3.347% more hydrogen than the PEM electrolyzer. In addition, a 20% increase in electrolyzer efficiency raises hydrogen production by 32.35%, whereas the same increase in compressor efficiency improves production by 0.758%. These impacts directly correlate with proportional reductions in the photovoltaic panel surface area, driven by increased electricity generation capacity, which translates into smaller infrastructure needs. The model enables quantitative evaluation of trade-offs among solar irradiance, component performance, and system design. It supports cost reduction through optimized sizing and improved integration. This approach contributes to lowering the Levelized Cost of Electricity (LCOE) and promoting the viability of marine-based green hydrogen deployment. Full article

Exposure to ultraviolet (UV), particularly UVA radiation, is a primary driver of photoaging due to its deep dermal penetration, which triggers DNA damage, collagen degradation, and immune suppression. Chebulinic acid (CA), a polyphenolic compound from Terminalia chebula, exhibits potent antioxidant and anti-inflammatory properties against UVB-induced skin damage. However, its large molecular weight hinders transdermal delivery and the TAT_47–57 peptide (core of HIV-1 TAT) enables rapid transmembrane transport. Large particles with double-layer membrane structure and a diameter exceeding 1000 nm were obtained during the separation of plant-derived exosome-like nanoparticles (PELNs), which are not considered as PELNs (50–500 nm), after a mixture with TAT anchored to the surface of engineered artificial vesicles (EAVs) and extrusion causes membrane fusion, employed as novel nanocarriers to overcome the difficulty in skin penetration by leveraging their lipid bilayer structure and surface membrane-anchored TAT for efficient epidermal fusion and intercellular penetration. Furthermore, CA-loaded TAT-ePELNs demonstrate significant efficacy in mitigating UVA-induced photoaging. Collectively, this study expands the anti-UVR damage application spectrum of CA from UVB to UVA exposure and establishes a green, efficient, and biosafe strategy for transdermal drug delivery by utilization of non-PELNs generated during the preparation process of PELNs. Full article

Green hydrogen is commonly assessed as a renewable fuel or long-duration storage option, but its value as a critical-load restoration resource remains less developed, particularly when produced from curtailed renewable electricity. This study develops a planning-oriented framework to assess green hydrogen for critical-load restoration by linking renewable curtailment, proton-exchange membrane electrolysis, hydrogen storage, fuel-cell reconversion, critical Energy Not Served (ENS) reduction, economic valuation, and carbon-footprint savings. The framework is applied to the Dominican Republic power system as a representative insular case with rapid renewable expansion and limited flexibility. Using monthly preliminary real-operation reports from OC-SENI, the reference case considers 196.46 GWh/year of curtailed non-conventional renewable electricity in 2025, producing 3.78 kt H₂/year and 65.5 GWh/year of recoverable electricity. Under the reference screening assumptions, a 25 t H₂ storage module would provide 433.29 MWh of usable electricity, fully covering 6 h and 12 h restoration windows for the 30 MW illustrative critical-load case and reducing critical ENS by 60.2% during a 24 h event. The recovered electricity could avoid 43.5 ktCO₂/year under the SENI combined-margin grid-displacement case, with higher avoided operational emissions under the diesel-backup displacement sensitivity. Full article

The growing deployment of green hydrogen technologies is increasing pressure on freshwater resources, motivating the exploration of alternative water sources that do not compete with human consumption. In this work, the direct use of untreated produced water from the Shushufindi 78 oil well (Ecuador) as an electrolyte for the hydrogen evolution reaction (HER) was experimentally evaluated. A comprehensive physicochemical characterization combined with electrochemical techniques, electrochemical impedance spectroscopy (EIS), and gas chromatography (GC-TCD) was performed to correlate electrolyte composition with electrochemical performance. Despite the high salinity and complex composition of the electrolyte, hydrogen production was achieved without pretreatment. Quantitative GC-TCD analysis yielded 10.29 µmol of H₂ after 4 h of electrolysis under non-optimized laboratory conditions, corresponding to a faradaic efficiency of 43.8%. These results demonstrate the feasibility of direct hydrogen generation from untreated produced water under realistic operating conditions. Additional experiments conducted in a membrane separated H-type electrolyzer evaluated mixtures of produced water and KOH, the electrolyte commonly employed in alkaline water electrolysis. Hydrogen production increased significantly under alkaline conditions, with the PW 10% + KOH 90% electrolyte exhibiting the highest hydrogen yield and faradaic efficiency among the investigated systems. Electrochemical impedance spectroscopy revealed that KOH addition reduced solution resistance and improved ionic transport, while differences in interfacial behavior were observed depending on electrolyte composition. The combined electrochemical and chromatographic results demonstrate that untreated produced water can be directly utilized for hydrogen production and can also be partially integrated into alkaline electrolysis systems without compromising electrochemical performance. These findings highlight the potential of produced water as a non-conventional water resource for sustainable hydrogen generation and industrial wastewater valorization. Full article

Under the background of the green transformation and energy conservation in the aviation field, hydrogen-fueled aero-engines are the primary direction for achieving sustainable aviation power development. However, the unique thermophysical properties of hydrogen fuel induce extreme thermal load challenges to engine thermal management. Based on the requirements of energy conservation and digital-intelligent technologies, this paper reviewed the recent research progress, important challenges, and future development directions in the thermal management field for hydrogen-fueled aero-engines, and filled the gaps in existing related reviews. (1) As for the liquid hydrogen thermal properties and thermal management requirements, the unique thermal physical properties of liquid hydrogen can easily cause fluctuations in heat load, large temperature differences, and material compatibility issues such as hydrogen embrittlement during storage, transportation, and combustion. The application of thermal barrier coatings, the design of targeted cooling structures, and the regulation of heat loss in the pipeline of the hydrogen supply system require particular attention. (2) As for the technical architecture and optimization of thermal management, the optimization of the high-pressure side manifolds in the cooled cooling air heat exchanger increases the flow uniformity by 18.8% and reduces the weight by 22.5%. The intercooled recuperated engine with the optimum area ratio reduces specific fuel consumption by 5.3% compared to the baseline engine in cruise. However, the system-level optimization research of the above widely recognized solutions is relatively limited in terms of coordinating the energy flow of engines. The baseline engine employed the method of system integration optimization to achieve a 2.99% increase in thrust and a 6.78% reduction in fuel consumption. (3) As for the thermal management modeling and simulation, the intelligent optimization method based on computational fluid dynamics reduces the pressure loss coefficient of the vane-integrated heat exchanger by 36%. Nevertheless, the multiphysics coupling model confronts a contradiction between computational cost and accuracy. (4) As for the comprehensive evaluation method, the advanced configuration of the hydrogen-fueled aero-engine can approximately reduce specific fuel consumption by 68.5% and NOx emission by 12.7% under the same maximum thrust condition. The hydrogen consumption of the proton exchange membrane fuel cells system model compared with the baseline system, optimized by the multi-objective optimization algorithm, has decreased by 15%, while the thermal uniformity has improved by 20–30%. However, the current evaluation system mostly focuses on a single dimension, lacking the analysis of nonlinear coupling among multiple factors and a closed-loop mechanism for evaluation, optimization, and verification. Future research should focus on the matching model of liquid hydrogen’s thermophysical properties and full flight conditions, global multi-energy flows optimization methods, multidimensional collaborative numerical simulation, multiphysics coupling models, and multidimensional comprehensive evaluation systems, to provide closed-loop theoretical support for the efficient, intelligent, and reliable thermal management system for hydrogen-fueled aero-engines. Full article

It is essential for quinoa’s rapid expansion in the global market to comply with the circular economy to become a green agro-food industry. For this purpose, in this work, bioactive added-value compounds, specifically saponins and phenolic antioxidants, were extracted and purified from quinoa by-products (QbP), namely hulls, using green solvent extraction (60 wt% ethanol-water) and nanofiltration (NF). So far, research published on the implementation of NF in the treatment of QbP, or modelization and optimization of the membrane performance focusing on fouling minimization and control, is scarce. Centrifugation and microfiltration were conducted as separation-purification pretreatments before NF. A three-level factorial design was successfully applied to optimize NF membrane operation in terms of saponins and phenolic compound recovery, as well as permeate flux, comprising operating pressure and tangential velocity as key input factors. Membrane fouling, critical for stable process operation scale-up, required intensive multifactorial analysis. Optimization at 4 bar and 15 m/s permitted the recovery of up to 84.5% saponins and 84.3% phenolic compounds in the permeate stream. Moreover, NF dynamic performance modeling and optimization ensured fouling build-up minimization and maximization of membrane productivity almost ten-fold, up to a stable value as high as 175.4 L/hm², ensuring full recovery of the membrane performance after each operating cycle, key for the technical–economic viability of the proposed process to obtain standardized purified extract products. Full article

This study focuses on sustainable atmospheric water harvesting (AWH) using film-containing green nanomaterials. Particular emphasis is given to chitosan as a sustainable biopolymer matrix due to its intrinsic hydrophilicity, biodegradability, film-forming ability and abundance of amino and hydroxyl functional groups that favor water adsorption and nanoparticle interaction. ZnO, SiO₂ and Fe-Zn-SiO₂ nanoparticles with abundant hydroxyl groups were synthesized from plant-based materials such as biomass from peanut and banana wastes, as well as plant extracts. Nanocomposite membranes containing nanoparticles with a high specific surface area and moisture-sensitive behavior were successfully developed. Results showed that bilayer films outperformed monolayer systems in water harvesting performance. In particular, the bilayer film composed of Chitosan/G-ZnO (10 wt.%) on the top layer and Chitosan/G-SiO₂ (10 wt.%) in the bottom layer displayed outstanding hydrophilic properties with water contact angles reduced to 42–43°. The material demonstrated an equilibrium adsorption capacity for water at 0.90 g/g and a passive yield of 1.5–2.2 mL/g per day. The improved adsorption behavior was attributed to the synergistic effect between the hydroxyl-rich oxide nanoparticles, the intrinsic water affinity of chitosan, and the layered porous structure. Moreover, the samples showed good thermal and mechanical stability and retained their structure after several uses. These findings highlight the potential of chitosan-centered green nanocomposites as sustainable materials for passive AWH applications. Full article

The overreliance on chemical pesticides has caused severe environmental contamination, health risks, and increasing pest and pathogen resistance, creating an urgent need for greener and more efficient alternatives in sustainable agriculture. Microalgae-mediated green nano-synthesis has emerged as a promising strategy because of its environmental compatibility, cost-effectiveness, and multifunctional potential. This review critically summarizes recent advances in microalgae-derived nanomaterials for agricultural applications. First, we discuss the biochemical basis of nanoparticle biosynthesis, highlighting the roles of microalgal polysaccharides, proteins, photosynthetic pigments, extracellular polymeric substances, and secondary metabolites as reducing, capping, and stabilizing agents. We then summarize intracellular and extracellular synthesis pathways, advanced synthesis strategies, and key reaction parameters, including temperature, pH, and metal precursor concentration, which regulate nanoparticle size, morphology, stability, and yield. Subsequently, major microalgae-derived nanomaterials, including gold, silver, selenium, zinc oxide, bimetallic, and other functional nanoparticles, are discussed in relation to their agricultural applications. These nanomaterials show potential in bacterial, fungal, and viral disease control, biofilm disruption, plant growth promotion, yield enhancement, and abiotic stress mitigation. Their agronomic effects are associated with multiple mechanisms, including reactive oxygen species generation, pathogen membrane disruption, inhibition of biofilm formation, enhanced nutrient bioavailability, antioxidant regulation, and activation of plant systemic resistance. In addition, this review evaluates the phytotoxicity, biocompatibility, soil microbial impacts, and environmental safety of microalgae-derived nanomaterials, emphasizing that green synthesis does not automatically guarantee biosafety. Finally, we discuss their integration into circular agriculture through CO₂ capture and wastewater-derived metal recovery, while highlighting remaining challenges in scale-up, quality control, economic feasibility, regulatory classification, and public acceptance. Overall, microalgae-mediated nanotechnology offers a promising platform for developing safer, more efficient, and circular agricultural inputs. Full article

The red imported fire ant (Solenopsis invicta Buren) is a destructive invasive pest, and conventional chemical control faces challenges related to environmental contamination and resistance development, highlighting the need for novel control agents and greener management strategies. In this study, pyrethrins-mediated silver nanoparticles (Pyr-AgNPs) were synthesized via a green route, characterized, and evaluated for their insecticidal activity, environmental stability, and metabolic effects on S. invicta workers. Bait bioassays showed that Pyr-AgNPs exhibited high toxicity to S. invicta, causing 100% cumulative corrected mortality at 500 mg·kg⁻¹ after 9 days of feeding, with a 5-d LC₅₀ of 116.83 mg·kg⁻¹. Exposure assays further demonstrated that Pyr-AgNPs had good environmental stability and residual efficacy, as bait containing 1000 mg·kg⁻¹ Pyr-AgNPs still caused 100% cumulative corrected mortality after 9 days following 96 h of outdoor exposure, significantly outperforming the pyrethrins treatment. LC-MS-based untargeted metabolomic analysis revealed that treatment with Pyr-AgNPs markedly altered the metabolic profile of S. invicta workers, with 607 differential metabolites identified, mainly belonging to organic acids and derivatives, lipid and lipid-like molecules, amino acids and peptides, cofactors, and redox-related metabolites. Pathway enrichment analysis indicated that these metabolic disturbances were primarily associated with energy metabolism, redox homeostasis, and membrane lipid metabolism. Overall, these findings provide preliminary mechanistic clues into the toxicity of Pyr-AgNPs and support their potential application in the sustainable management of S. invicta. Full article