Search Results (7,554)

Soil contamination by heavy metals (HMs) [or potential toxic elements (PTEs)] poses serious risks to ecosystems and human health. Metals persist in the environment and can reach groundwater and freshwater as part of the food-chain. In soils, anthropogenic inputs dominate over geogenic sources. Metal mobility is strongly controlled by factors such as pH, mineralogy, and erosion processes that transport metal-bearing clay fractions. Wind and water can transport soil, mainly clay particles that can usually bind contaminants such as HMs. Using waste material is a tool suggested from the circular economy, so waste becomes a valuable resource. This study evaluates the immobilization efficiency of several heavy metals (Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn) using phosphate amendments—synthetic hydroxyapatite, phosphatic rock from Florida and Morocco—applied to a brownfield site. Heavy metal immobilization followed a two-step mechanism: first rapid surface complexation and secondly partial dissolution of hydroxyapatite and ion exchange with Ca, leading to the precipitation of metal-substituted hydroxyapatite phases. Synthetic hydroxyapatite generally shows the best efficiency, whereas phosphatic rocks were less effective but still provided a measurable immobilization. From a circular economy perspective, however, phosphatic rocks remain attractive due to their lower cost, availability, and waste-valorization potential. Full article

The prevention and control of forest fires are of vital importance for ecological security. The efficiency and environmental friendliness of fire-extinguishing agents remain the core focus of current research. This paper reviews the research progress and fire extinguishing mechanisms of three types of forest-fire-extinguishing agents, namely, foam extinguishing agents, gel extinguishing agents, and fire-resistant barrier materials. These three types of extinguishing agents work together to extinguish fires through three principles: isolating combustibles, reducing the oxygen concentration, and lowering the temperature. This paper systematically summarizes the performance evaluation methods, covering the cooling rate, fire extinguishing time, and re-ignition rate, and combines numerical simulation and field experiments to build a multi-scale verification system. The environmental assessment focuses on biodegradability, the ecological toxicity to soil and water systems, and the impact on plant germination and biodiversity. It clearly indicates that degradability, low toxicity, and low residue are key development directions. The current research still needs to further deepen in aspects such as long-term stability, adaptability to complex terrains, and ecological risk assessment during the life cycle. In the future, priority should be given to promoting green, multi-functional, and precise application technologies to provide solid support for scientific forest fire prevention and ecological protection. Full article

In the seasonally frozen area, slopes are exposed to freeze–thaw cycles; thus, water and heat are moved, and the foundation for the transportation infrastructure in cold regions may be weakened. Based on the relatively strong water-recharge effect and considerable fluctuations in shallow soil moisture during the spring thaw along the Naba section of the G218 Highway in Xinjiang, China, a coupled hydro-thermal model for frozen soil that considers snowmelt infiltration and rainfall recharge was developed, and it was numerically implemented in COMSOL. A one-dimensional unidirectional freezing test of a soil column was used to validate the model, and the relative errors of the simulated temperature and moisture fields were 3.8% and 4.3%, respectively; both are within the accuracy requirements for engineering-scale analysis. Then, a model was used to determine how the temperature, volumetric ice content and volumetric water content of a representative slope in the Naba section changed during a freeze–thaw cycle. Based on the above results, the annual temperature range at the surface of the topsoil on the slope is 37.61 °C, and this thermal effect extends to a depth of 0–3 m. In the spring thaw, the volumetric water content of the surface layer increased from 8.45% in February to 19.34% in May, and further to 20.65% in July; therefore, it can be inferred that the shallow soil is still being replenished by snowmelt and rain. Freezing-thaw phase change, freezing-front migration and external water infiltration work together to control hydro-thermal transport in the slope; thus, a redistribution and local accumulation of liquid water occur below the residual frozen layer and under the shallow surface. The above results can serve as a reference for drainage design and as a means to prevent or control freeze–thaw damage to the slope of a highway in Xinjiang’s seasonally frozen area during the spring thaw. Full article

Achieving efficient demulsification of water-in-heavy oil (W/HO) emulsions remains a critical issue that urgently needs to be addressed in the heavy oil industry. Despite being a new generation of green demulsification materials, magnetic carbon nanoparticles still suffer from low demulsification efficiency when applied to water-in-heavy oil emulsions. Herein, polyethyleneimine-modified magnetic carbon nanoparticles (P-MCNs) were successfully prepared via a surface functionalization strategy. The demulsification performance of P-MCN in water-in-heavy oil (W/HO) emulsions was evaluated via the standard bottle test. The results demonstrated that P-MCN (500 ppm) achieved effective water removal within 60 min at 50 °C. Microscopic visualization characterization revealed that the efficient water removal from W/HO emulsions by P-MCN is attributed to its high interfacial activity. Specifically, P-MCN can rapidly migrate to the heavy oil–water interface and effectively disrupt the interfacial film through electrostatic interactions and hydrogen bonding, thereby achieving efficient demulsification of W/HO emulsions. This study provides a solid theoretical foundation for the further development of magnetic carbon nanoparticles with higher demulsification efficiency for applications in the petroleum industry. Full article

Plasma membrane intrinsic proteins (PIPs), a subfamily of aquaporins (AQPs), play critical roles in various physiological processes in plants, including the transport of water and CO₂, regulation of stomatal movement, absorption of neutral molecules and nutrients, and H₂O₂ signaling. Nevertheless, the functions of PIP aquaporins in adventitious root formation in trees are still poorly understood. PtrPIP2:4 is specifically expressed in roots, and PtrPIP2:4 fused with GFP localizes to the plasma membrane. Overexpression of PtrPIP2:4 significantly accelerated adventitious root induction in poplar. Stem cuttings from overexpression lines exhibited more rapid rooting compared to wild-type (WT) plants, although the total number of adventitious roots did not differ significantly. Additionally, the number of lateral roots was markedly increased in PtrPIP2:4 overexpression lines. Comparative transcriptome analysis identified 4204 differentially expressed genes (DEGs) between WT and PtrPIP2:4 overexpression plants. Transcriptomic analysis revealed that genes associated with auxin-related and flavonoid biosynthesis were significantly enriched. RT-qPCR results showed that the transcription levels of nine auxin-related genes (i.e., PtrARF, PtrIAA, PtrGH3 and PtrPIN) were significantly upregulated, while the transcription levels of five flavonoid synthesis genes (i.e., PtrDFR, PtrANS, PtrANR and PtrLAR) were also significantly upregulated. Previous studies have implicated these genes in adventitious root formation. Collectively, these findings reveal that PtrPIP2:4 accelerates adventitious root emergence, promotes adventitious root elongation, and increases lateral root number while the total number of adventitious roots exhibited no significant difference in poplar, suggesting its potential utility in improving tree propagation and breeding strategies. Full article

Superhydrophobic materials offer promising prospects for utilization in energy, environmental, and related fields. However, their long-term stability in natural environments is constrained by factors such as mechanical wear and aging, which compromise their practical effectiveness and service life. While notable experimental results have been obtained worldwide, scalable application remains limited by the complexity of the requisite fabrication processes. In this study, a durable superhydrophobic coating was developed through a facile one-step process, utilizing a polyaspartic ester (PAE) matrix reinforced with a composite of self-synthesized fluorinated silica (F-SiO₂) and hexagonal boron nitride (h-BN) micro-/nano-structures. This strategy effectively enhanced filler dispersion within the resin matrix and promoted hydrophobicity, yielding a stable superhydrophobic surface. The resulting coating exhibits significant potential for scalable application. The optimized coating demonstrated a water contact angle of 161.2° and a roll-off angle of 7.6°, showing excellent repellency to water, corrosive liquids, and fluids across a wide pH range, along with remarkable self-cleaning performance. Benefiting from the synergistic enhancement of h-BN and F-SiO₂, the coating also exhibits superior mechanical durability, maintaining a contact angle of 144.4° after 1000 abrasion cycles. Furthermore, in low-temperature anti-icing tests, the coating significantly delayed ice formation on its surface. Notably, after 1000 h of UV aging tests, the F-SiO₂@BN/PAE coating retained its intact superhydrophobic structure, with the water contact angle only slightly decreasing from 159.6° to 152.8°, still within an excellent superhydrophobic state, demonstrating outstanding weather resistance. By integrating surface functionalization with mechanical reliability through a facile one-step fabrication process, this study provides significant insights for the large-scale application of hydrophobic materials in the energy and transportation sectors. Full article

Global food production systems are increasingly challenged by population growth, climate change, water scarcity, and environmental degradation, necessitating the adoption of sustainable, resource-efficient food production strategies. Aquaponic systems integrate recirculating aquaculture with hydroponic crop cultivation, enabling nutrient recycling and improved water-use efficiency. Simultaneously, CRISPR/Cas9 genome-editing technology has emerged as a powerful tool for precise genetic improvement of economically important aquaculture traits. This review critically evaluates current progress in CRISPR/Cas9 applications in aquaculture, with emphasis on Nile tilapia (Oreochromis niloticus). Evidence from peer-reviewed studies indicates that targeted modification of genes associated with growth regulation, disease resistance, nutrient metabolism, feed efficiency, and stress tolerance can significantly enhance fish productivity and physiological resilience. Genes involved in hypoxia adaptation and nitrogen metabolism may further improve environmental performance in intensive recirculating systems by reducing ammonia accumulation and enhancing nutrient utilization. However, most genome-editing studies have been conducted under laboratory or conventional aquaculture conditions, with limited information available regarding the long-term performance, ecological interactions, microbial dynamics, and biosafety of genome-edited fish in aquaponic environments. Technical limitations including off-target effects, mosaicism, delivery efficiency, regulatory uncertainty, and public acceptance continue to constrain large-scale implementation. In the short term, CRISPR/Cas9 applications are likely to focus on practical trait enhancement under controlled aquaculture systems, whereas longer-term research may explore fish lines specifically optimized for nutrient cycling, environmental resilience, and integrated aquaponic sustainability. Overall, CRISPR/Cas9-mediated genome editing represents a promising but still emerging strategy for improving sustainable aquaculture and aquaponic food production systems. Full article

The decarbonisation of the building sector represents a key challenge for the European energy transition, particularly in the heating segment, which is still largely dependent on fossil fuels. In this context, data centres (DCs) offer a promising opportunity as local sources of recoverable waste heat. This study investigates the use of data centre waste heat for building heating through a comparative annual energy analysis applied to two building typologies in a Mediterranean climate (Italy): a residential building and a school. Three scenarios are considered: non-integrated scenario S0 (data centre with its own cooling system and buildings with gas-fired boilers), non-integrated scenario S1 (data centre with its own cooling system and buildings with air-to-water heat pumps), and integrated scenario S2 (data centre cooling system coupled with the buildings through waste heat recovery and heat pump technology). A theoretical 300 kW data centre was considered as the waste heat source. The integrated scenario significantly improves system performance. In the residential case, the seasonal COP increases from 2.15 to 4.50, reducing electricity consumption from 289.5 MWh to 128.9 MWh. In the school case, the COP increases from 2.51 to 8.00, with electricity consumption decreasing from 161.3 MWh to 49.1 MWh. These improvements lead to reductions in non-renewable primary energy demand of up to 63% and 79% for the residential and school buildings, respectively, compared to the baseline scenario. The results demonstrate that data centres can act as decentralised thermal sources, supporting the transition towards low-carbon and Nearly Zero-Energy Buildings. Full article

Exhaust piping in diesel engines is subject to severe thermal stress arising from high-temperature, high-pressure gas flows, and spray cooling with atomizing nozzles has become a widely adopted method to safeguard structural reliability. However, at present, the understanding of the spray fragmentation mechanism of two-phase flow under low inlet pressure is still not comprehensive. This study establishes a three-dimensional model of a gas–liquid impinging-jet nozzle and applies a coupled Volume-of-Fluid to Discrete-Phase-Model (VOF–DPM) approach to resolve the liquid breakup process in detail. High-speed imaging experiments were carried out to validate the numerical results. Orthogonal tests were conducted at five pressure levels for both gas and water—0.28, 0.24, 0.20, 0.16, and 0.12 MPa—producing 25 data pairs of spray cone angle and Sauter Mean Diameter (SMD). Within the 0–0.3 MPa air inlet pressure range explored here, raising the pressure consistently reduced the SMD and widened the cone angle, although both trends weakened as the pressure increased. Water inlet pressure exhibited a nonlinear influence, with local extrema appearing in the higher-pressure region. The overall SMD reached a minimum of 34.12 μm and a maximum of 149.04 μm. Using these 25 data points, a genetic algorithm was employed to optimize the pressure ratio under the constraint of total hydraulic power, yielding optimization strategies for different power budgets. An additional outcome of the simulation was the identification of a structural weakness: by reshaping the original flat impingement surface into a full conical surface, atomization quality improved by 29.36% under identical boundary conditions. These findings clarify the atomization mechanism of gas–liquid impinging jets under low inlet pressure and offer practical guidance for nozzle optimization. Full article

Arid regions are ecologically fragile and occupy a substantial portion of the global terrestrial surface. In these regions, ecosystem services (ESs) are strongly constrained by water availability and, more importantly, by the balance between water supply and demand. However, the nonlinear responses and threshold mechanisms linking water supply–demand balance to ES dynamics remain unclear. Taking the Kubuqi Desert in the “Great Bend” of the Yellow River as the study area, this study quantified the Comprehensive Ecosystem Service Index (CESI) and the Water Supply–Demand Ratio (WSDR) by integrating the InVEST model, RWEQ model, the RUSLE model, Water Balance Method, and so on. The dual-constraint line method and elasticity coefficient approach were integrated to identify the constraint effects and critical thresholds of WSDR on CESI. Ecological management zones were further delineated by integrating the inflection-point intervals of the dual-constraint lines with the threshold intervals identified by elasticity coefficients. The results showed that CESI remained relatively low, with a maximum value of approximately 0.5, suggesting that the overall ES level was still limited, but exhibited a continuous increasing trend. The regional water supply–demand pattern gradually shifted from deficit toward relative balance, although agricultural water use still accounted for about three-quarters of total consumption. CESI showed a nonlinear threshold response to WSDR: mild water deficit suppressed CESI growth, whereas moderate water surplus promoted CESI recovery by alleviating water constraints and improving ecosystem functioning. Thresholds identified by elasticity coefficients mainly occurred near critical transitions between water deficit and surplus. Based on ES supply and threshold sensitivity, nine ecological management zones were identified, with priority enhancement areas accounting for approximately 75%. These findings provide a threshold-based basis for ecological zoning and differentiated restoration in arid regions. Full article

The critical checklist of the marine fishes of Malta and surrounding waters published by the present authors in 2023 provided the first evidence-based assessment of the marine ichthyofauna of the Maltese Islands. Since then, new faunistic, fisheries-related, and molecular data have become available, justifying an update. The present work critically reviews the scientific and selected popular literature published up to April 2026, applying the same study area and authentication criteria adopted in the 2023 checklist. The update affects 22 species: six are newly reported from Maltese waters, of which two still require confirmation; nine species previously treated as unconfirmed and three species originally excluded are here confirmed; two species formerly known only from historical records are also confirmed; and two species are excluded on the basis of revised taxonomic or biogeographical knowledge. Consequently, the number of confirmed species increases from 412 to 426, the number of unconfirmed species decreases from 53 to 45, and the number of excluded species decreases from 78 to 77. Within the confirmed fauna, native species increase from 370 to 379, non-established alien species from 17 to 19, and non-established Atlantic immigrants from 3 to 6, whereas the numbers of established aliens, established Atlantic immigrants, and cryptogenic species remain unchanged. The changes documented here reflect improved sampling, especially of deep-water species, the resolution of taxonomic uncertainty through molecular analyses, and the continued arrival of newcomer species. This updated checklist provides a more accurate and current baseline for future faunistic, biogeographical, ecological, conservation, and fisheries-related studies on the marine fishes of Maltese waters. Full article

Tunnel seepage in heterogeneous ground can trigger hydrogeological hazards such as concentrated water inflow, groundwater depletion, deformation of surrounding structures, and subsequent eco-environmental degradation. However, these processes are still commonly evaluated using deterministic models that neglect the spatial variability of hydrogeological parameters. To address this limitation, this study develops a stochastic hydro–geo–mechanical–ecological framework that integrates random field theory with physics-informed neural networks (PINNs) for hazard evaluation and rapid prediction of tunnel seepage responses. The spatial variability of key parameters, including permeability and porosity, is characterized using the Karhunen–Loeve expansion and embedded into coupled governing equations for unsaturated–saturated seepage, seepage–stress interaction, and groundwater–soil–vegetation responses. A PINN surrogate model with random-field inputs is then constructed to predict hydraulic head, tunnel inflow, displacement, groundwater depth, vegetation coverage, and soil physicochemical indices, while simultaneously quantifying uncertainty. A karst tunnel case in Chongqing, China, is used to demonstrate the proposed framework. The results show that spatial heterogeneity promotes preferential flow paths and intensifies seepage-induced hazards compared with deterministic mean simulations, leading to larger groundwater drawdown, stronger ecological degradation, and greater overall response variability. The proposed PINN achieves high predictive accuracy (R² > 0.97) and reduces single-case computational time from hours to seconds, enabling efficient multi-scenario evaluation and uncertainty-aware risk assessment. This framework provides a physically consistent and computationally efficient tool for evaluating water-related hazards and long-term environmental impacts in underground engineering. Full article

Ferns represent an evolutionarily distinct group of vascular plants and constitute an underexplored source of structurally diverse secondary metabolites with potential medicinal value. Several fern-derived compounds, including sesquiterpenes, triterpenes, flavonoids, phloroglucinol derivatives, lactones, and glycosides, have been associated with antibacterial, antidiabetic, analgesic, anticancer, hepatoprotective, neuroprotective, and other biological activities. However, despite their biochemical uniqueness and long-standing use in traditional medicine, ferns remain less extensively investigated than angiosperms as sources of bioactive compounds. In addition to their natural phytochemical diversity, the production of secondary metabolites in ferns may be influenced by abiotic stressors, such as light quality and intensity, temperature, salinity, drought, water availability, and mineral nutrition. Available studies indicate that selected abiotic stress conditions can enhance the accumulation of phenolic acids, flavonoids, polyphenols, carotenoids, and related compounds in several fern families, including Aspleniaceae, Athyriaceae, Dryopteridaceae, Onocleaceae, and Thelypteridaceae. Nevertheless, information on stress-induced modulation of metabolites that are unique or highly characteristic of ferns, particularly terpenes, terpene glycosides, and specific flavonoid derivatives, remains limited. This review summarizes the current knowledge on unique secondary metabolites in ferns, their reported medicinal properties, and the potential use of abiotic stress as an elicitation strategy to enhance their production. Overall, the review highlights ferns as promising but still insufficiently explored reservoirs of bioactive metabolites and identifies key directions for future phytochemical, pharmacological, and cultivation-based research. Full article

The transition towards a circular economy in architecture requires new methods for reusing construction and demolition waste as a material resource. Recycled aggregates are a promising alternative to natural aggregates, although their variable porosity and particle grading often limit practical application. This study evaluates the suitability of recycled concrete aggregate (RCA) and recycled ceramic aggregate for small-scale architectural elements such as street furniture. Three comparative mixtures were analysed using particle size distribution data, the Modified Andreasen model, and the EMMA (Elkem Materials Mix Analyzer) tool. Two mixtures contained recycled aggregates, while one reference mixture was based on natural aggregates. The assessment focused on particle packing, water demand, and binder content. The recycled concrete aggregate mixture showed results closest to the reference mix, with water content of 180 kg/m³ and a water-to-cement ratio of 0.50, compared with 170 kg/m³ and 0.50 for the natural aggregate mixture. The ceramic aggregate mixture required the highest water content (200 kg/m³) and cement dosage (380 kg/m³) due to its higher porosity (15–18%) and finer particle fraction. By adjusting aggregate proportions within the packing model, satisfactory particle structuring was still achieved in all mixtures (q = 0.31–0.35). The study shows that particle packing methods, commonly used in concrete technology, can also support early-stage architectural material selection. Recycled aggregates, particularly RCA, may therefore be considered a viable substitute for natural materials in benches, seating panels, and other small-scale circular design applications. Full article

Sea level rise poses a major threat to dry beach areas, particularly in low-lying and managed coastal environments. Reliable assessments of future beach vulnerability therefore require the combined consideration of sea level rise, tidal regime, meteorological forcing, and wave-driven processes. Here, a physically based methodology is applied to evaluate future inundation and beach response at five representative sandy beaches along the southern coast of Spain. The selected sites span mesotidal Atlantic and microtidal Mediterranean settings. The approach integrates present-day conditions with sea level rise projections under RCP 4.5 and RCP 8.5 scenarios, astronomical tide, and meteorological residuals. Wave run-up is estimated using the IH2VOF CFD (Computational Fluid Dynamics) model. Extreme still water levels and maximum inundation levels are derived for mid-century (2026–2045) and end-of-century (2081–2100) periods, and their impacts on available dry beach surface and beach width are quantified using cross-shore profiles. Results indicate a progressive reduction in dry beach surface and width across all sites, with impacts intensifying from mid- to end-century and from moderate to high-emission scenarios. While losses remain comparatively moderate under still-water assumptions, the inclusion of wave effects leads to substantially larger impacts. At the most vulnerable sites, dry beach surface losses reach up to 80% under still-water conditions, and up to complete loss (100%) when wave run-up is included, particularly along the mesotidal Atlantic coast. Overall, the results demonstrate that neglecting wave run-up can lead to a substantial underrepresentation of future beach inundation, and that its explicit inclusion provides a more reliable basis for beach management and adaptation planning under sea level rise. Full article