Search Results (191)

This study reports the synthesis of low-defect Prussian blue analogues (PBAs) using a single iron-source method and systematically investigates the influence of atmospheric components, particularly water and oxygen, on their oxidative decomposition. Our findings demonstrate that the oxidative degradation of PBAs is governed synergistically by moisture and oxygen, with ambient humidity identified as the primary factor determining both the extent and kinetics of their decomposition. Notably, a pure oxygen environment by itself does not trigger material degradation, while oxygen markedly accelerates the decomposition only in the presence of moisture. As a result of the oxidation, enhanced Coulombic interaction between sodium ions and cyano groups induces structural modifications in the lattice framework, driving a phase transformation from monoclinic to cubic symmetry, accompanied by changes in its unit cell volume. Furthermore, in high-humidity environments, atmospheric moisture promotes the gradual deintercalation of sodium ions from the Prussian blue framework, resulting in the conversion of sodium-rich Prussian blue to the sodium-deficient form. Concurrently, an increase in lattice defect density leads to partial structural collapse, inducing the release of free ferrocyanide ions, which may subsequently react with the deintercalated sodium ions to form the sodium ferrocyanide impurity phase. We also find that the preferential decomposition of low-spin iron over high-spin iron within the framework leads to a further reduction in its electrochemical capacity. In contrast, potassium Prussian blue exhibits minimal interaction with water molecules and can effectively repel them through steric hindrance. Therefore, partial substitution of sodium with potassium ions is proposed as a viable strategy to enhance the structural stability of the Prussian blue framework, improve the storage performance of sodium Prussian blue (NaPB), and mitigate water ingress. This work offers fundamental insights into the storage characteristics and oxidative degradation mechanisms of PBAs. Full article

Agricultural sustainability assessment is increasingly required to characterize how food production systems interact with land, soil, water, carbon dynamics, and broader environmental change. However, the extent to which scientific assessment methods capture these environmental-system interactions remains unclear. This study mapped methodological and thematic trends in agricultural sustainability research through text mining of 3302 bibliographic records retrieved from the Web of Science Core Collection, which was selected because of its standardized metadata structure and suitability for reproducible text-mining analysis, covering publications from 2003 to 1 March 2025. After corpus preprocessing and tokenization, term-frequency analysis, dimension-specific lexical classification, co-occurrence networks, and temporal bibliometric trends were used to identify dominant environmental themes and assessment approaches. The results revealed a clear predominance of the environmental dimension in the analyzed literature, particularly through terms associated with land, carbon, soil, and water resources, whereas social and economic dimensions displayed lower lexical representation. Food, production, and systems formed a central semantic cluster linking environmental assessment with food security. Life Cycle Assessment (LCA) was the most frequently identified methodology, reflecting the prominence of impact-oriented environmental evaluation. In contrast, integrative and farm-scale frameworks, including Driver–Pressure–State–Impact–Response (DPSIR), Sustainability Assessment of Food and Agriculture Systems (SAFA), and the Tool for Agroecology Performance Evaluation (TAPE), among others, indicated increasing attention to governance, resilience, and agroecological transitions. These findings show that text mining can support environmental research by identifying methodological biases and emerging priorities in agriculture–environment interactions. Strengthening integrated assessment approaches will be essential for managing natural resources and supporting resilient and environmentally sustainable food systems. Full article

Water resources are essential for human well-being. However, water pollution is a major global problem with significant implications for the environment and public health. To address these challenges, this study presents an integrated perspective on water pollution by correlating pollution sources, transport pathways, exposure routes, and associated risks to human health. The methodology combined a systematic review conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines with a bibliometric analysis performed by using VOSviewer version 1.6.19, a software tool for constructing and visualizing bibliometric networks. A total of 332 publications published between 2015 and 2025 were retrieved from the Scopus and Google Scholar databases and met the PRISMA eligibility criteria. The findings indicate that both natural and anthropogenic sources contribute to water contamination, introducing pollutants such as heavy metals, pesticides, pharmaceutical residues, microplastics, and pathogenic microorganisms with potential human health impacts. Bibliometric analysis revealed a transition from conventional water quality assessments toward integrated approaches emphasizing health risks and environmental interactions. The study further identified important knowledge gaps regarding contaminant mixture effects and synergistic toxicity, which remain insufficiently addressed in current scientific and regulatory frameworks. These findings highlight the need for strengthened regulatory strategies, advanced treatment technologies, and evidence-based water governance to support environmental sustainability and public health protection. Full article

Freshwater scarcity is driving the construction industry to seek alternative mixing waters, and seawater is an abundant resource; however, its suitability is commonly judged by total salinity, which overlooks the fact that coastal seawater chemistry varies hugely between locations and may govern long-term strength performance in varying locations. To address this problem, this study investigates the long-term strength performance and its microstructural and phase transformation of cement mortars mixed with seawater, with the aim of establishing a technical understanding between region-specific seawater chemistry and mortar strength. Seawater was collected from four coastal locations in Tamil Nadu, India, and characterized for chloride, sulfate, magnesium, organic solids, and related parameters. The cement mortar cubes were cast with each seawater, and compressive strength was measured from 3 to 360 days; the microstructural and phase changes underlying the strength behavior were examined at 360 days using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). All samples showed accelerated early-age strength gain from the catalytic effect of chloride and sulfate ions, followed by strength loss at later ages caused by the same ionic environment, with a critical strength loss between 28 and 56 days. The Chennai sample, with the highest chloride and sulfate concentrations, suffered the most severe degradation of 11.5% loss of peak strength, which is attributed to ettringite and gypsum formation together with magnesium attack that consumed Portlandite to form non-cementitious brucite and secondary Calcite. In contrast, the Rameshwaram sample, with exceptionally low sulfate, exhibited superior stability with 3.5% loss, while Puducherry and Tuticorin showed intermediate degradation of 3.9% and 7.8% respectively, with the Puducherry sample further compromised by high organic solids. The results identify the chloride to sulfate ratio, rather than total salinity, as the key predictor of long-term strength performance. The main takeaway for the cement industry is that the suitability of seawater as mixing water is highly site-specific, and a detailed chemical analysis quantifying sulfate and magnesium content is an indispensable prerequisite for strength assessment and material selection before seawater is adopted in marine and coastal construction. Full article

Aluminum alloys are attractive for oil production, refining, and hydrocarbon-processing equipment because of their low density, high specific strength, and heat-transfer properties; however, their use is limited by localized corrosion in chloride-, sulfur-, and water-containing environments. This review analyzes combined anodic oxide/polymer and anodic oxide/fluoropolymer coating systems as surface-engineering approaches for improving corrosion resistance, adhesion, and durability of aluminum alloys under such conditions. The reviewed data show that coating performance is governed by anodic oxide morphology, pore sealing or polymer impregnation, and oxide/polymer interfacial stability. Quantitative results indicate that anodizing and pore widening can increase aluminum/polyamide lap-shear strength from 5.0 to 17.4 MPa, while optimized interfacial treatment can provide 22.5 ± 0.5 MPa before aging and 18.1 ± 0.2 MPa after humid aging. Corrosion data show that anodizing can increase the polarization resistance of aluminum alloy 6061 in seawater from 17.2 kΩ·cm² to 2.24 MΩ·cm². For wear-related durability, optimized anodizing can increase the critical scratch load from 37.3 to 118.9 N. These values provide practical benchmarks for designing anodic oxide/polymer systems for complex oilfield and hydrocarbon-processing environments. Full article

The durability of cement-based materials is strongly affected by ionic ingress and transport within calcium silicate hydrate (C-S-H) nanopores, governing their long-term degradation in saline environments. However, the coupled effects of pore size and salinity on nanoscale ionic behaviors remain insufficiently understood, limiting the mechanistic interpretation of durability evolution in cementitious systems. Existing studies have mainly considered pore size and solution salinity separately, while a systematic understanding of their coupling effects on ionic spatial distribution, transport properties and regime transitions is still lacking. In this study, molecular dynamics simulations are performed for NaCl solutions confined in C-S-H nanopores with pore sizes of 2.5–12.5 nm and salinities of 0–2 M. Results show layered water and ion structures that become increasingly confined with decreasing pore size. Increasing salinity enhances ion accumulation while suppressing water mobility due to competitive adsorption. Ion diffusion is significantly lower than that of water molecules, while transport parallel to the C-S-H surface is much higher than in the perpendicular direction, indicating strong anisotropy. Regime-dependent diffusion behaviors are observed across pore size–salinity conditions. These findings deepen the understanding of water and ionic transport and adsorption, improving durability models for cement-based materials in construction engineering. Full article

Soil water availability, salinity dynamics, and nitrate transport are key factors controlling agricultural sustainability in arid environments characterized by limited water resources and high evaporative demand. This study evaluated the combined effects of soil texture, nitrate–nitrogen application, and sawdust mulching on soil water retention, evaporation losses, salinity redistribution, and nitrate movement in loamy sand and sandy clay loam soils under controlled greenhouse conditions. Results showed that soil texture was the dominant control on hydrochemical behavior, with sandy clay loam exhibiting higher water retention and lower drainage than loamy sand. Sawdust mulching significantly improved soil water conservation by reducing evaporation and stabilizing moisture distribution, while the 4 cm mulch treatment achieved the highest overall CSI performance. Evaporation strongly governed salinity accumulation in surface layers, whereas mulching reduced salt build-up and promoted a more uniform salinity profile. Nitrate transport closely followed water fluxes, resulting in higher leaching in loamy sand and greater retention in sandy clay loam. Increasing nitrogen application enhanced nitrate mobility and leaching in both soils. A Composite Sustainability Index (CSI) was developed to integrate soil water conservation, evaporation reduction, salinity control, and nitrate retention into a unified metric. Sensitivity analysis demonstrated that treatment rankings were largely unaffected by alternative weighting schemes, confirming the robustness of the CSI framework. The CSI identified mulch application, particularly the 4 cm mulch treatment, as the most effective management option based on overall sustainability performance. The CSI framework provides an integrated decision-support tool for evaluating coupled water–salt–nitrate interactions and improving water use efficiency and salinity management in arid agricultural systems. This study offers a novel integrated CSI-based framework for simultaneously quantifying hydrological and hydrochemical soil responses under mulch management in arid environments. Full article

The use of alternative water sources in construction, especially in regions with limited freshwater availability, makes the influence of mixing water composition on the durability of cement mortars a critical issue, particularly under aggressive conditions such as ammonium exposure (XA3). A clear difference in material behavior was observed before and after exposure to an aggressive aqueous environment, highlighting the importance of durability assessment under realistic service conditions. Cement mortar specimens prepared with tap water, distilled water, and modified waters containing Cl⁻, Ca²⁺, SO₄²⁻, and PO₄³⁻ ions were tested. The experimental program included flexural and compressive strength, water absorption, and residual properties after exposure to an NH₄Cl solution. Statistical analysis was performed using one-way ANOVA, correlation analysis, a heatmap, and PCA. Compressive strength varied within a narrow range (33.85–47.24 MPa), while flexural strength showed larger differences (5.21–10.40 MPa). After exposure, residual flexural strength decreased to 1.16–5.87 MPa and compressive strength to 23.92–37.68 MPa. The most severe degradation was observed for sulfate- and chloride-modified waters. Correlation analysis revealed weak dependence between flexural and compressive strength. ANOVA confirmed a significant influence of water composition (p < 0.05), with the strongest effect observed for residual compressive strength (η² = 0.81). The results demonstrate that mixing water composition is a key factor controlling durability in an XA3 environment. Compressive strength alone is not a reliable durability indicator. Durability is governed primarily by transport properties and microstructure. A multi-parameter approach is required for an accurate durability assessment. Full article

Aquatic environments that support tourism, including coasts, lakes, reservoirs, and estuaries, are experiencing accelerating eutrophication worldwide. This trend increases the frequency and intensity of algal blooms. These blooms undermine ecosystem services and weaken the socio-economic performance of destination areas. Despite these challenges, existing research remains fragmented. Aquatic sciences mainly examine nutrient enrichment and bloom dynamics. In contrast, tourism studies often treat blooms as episodic disturbances and rarely integrate exposure pathways, risk communication, or feedback to destination governance. This review synthesizes evidence across freshwater and marine systems to develop a coupled tourism–water ecosystem perspective. We link eutrophication drivers and bloom typologies to three dimensions. These are the degradation of tourism-supporting ecosystem services, compound health stressors, and communication filters. The first includes losses of water clarity and aesthetic value. The second involves multi-route exposure through contact, inhalation, and seafood ingestion. The third shapes perceived safety, trust, and behavioral adaptation. We further connect perceived health risks to observable tourist behaviors, including cancellation, destination substitution, and activity avoidance. These micro-level responses can aggregate into market-level demand contractions and consumption reallocation. They can also trigger regional economic cascades, including public management costs, employment impacts, and long-term reputational damage. Crucially, tourism is not merely a victim of blooms. It can also act as a reinforcing anthropogenic driver through wastewater burdens, infrastructure expansion, and pulse pressures. These pressures lower ecological resilience, especially under warming and hydrological stabilization. Finally, we identify governance leverage points. These include early-warning systems, threshold-based graded interventions, transparent risk communication, and integrated social–ecological modeling. These strategies can reduce uncertainty-driven losses and support adaptive destination management. Overall, this review reframes algal blooms as systemic social–ecological risks. It provides a structured basis for future empirical attribution and policy design in tourism-dependent waters under climate stress. Full article

Tropical estuaries are socioeconomically important yet highly vulnerable environments. In the eastern Amazon, the Pará River Estuary (PRE) and adjacent water bodies support the city of Belém and are increasingly affected by environmental pressures but remain underrepresented in numerical modeling efforts. The influence of key input parameters on hydrodynamic model performance in these systems remains poorly characterized, hindering the development of reliable simulation tools for this region. We present the calibration and validation of a two-dimensional hydrodynamic model for the PRE, Guajará Bay, and the Guamá River, examining how parameters such as bathymetry, roughness, and tidal and discharge forcings influence model performance. Delft3D-FM was applied using tidal harmonics and seasonal river discharge as primary forcings, with model skill evaluated against observed water levels and discharge across ten seasonally distinct scenarios over seven calibration iterations. Tidal forcing and bathymetric representation emerged as the dominant performance drivers: replacing global tidal datasets with locally derived harmonics substantially reduced simulation errors, and bathymetric refinements also improved discharge representation. Final performance met established satisfactory thresholds at the majority of observation points and cross-sections. The calibrated model provides a basis for investigating processes governed by local hydrodynamics, such as water quality assessments, contaminant dispersion, and infrastructure planning. Full article

Waterfront built environments are increasingly exposed to hydrological variability and climate-related pressures that challenge conventional land-based building typologies. This systematic review examines permanently buoyant floating systems and flood-responsive amphibious systems as water-adaptive approaches to climate adaptation and regenerative waterfront development. Peer-reviewed studies indexed in Scopus and Web of Science were reviewed for January 2015–August 2025, with searches last updated on 15 August 2025. The review combines PRISMA-guided selection, bibliometric mapping of the screened publication landscape (N = 1410), and qualitative synthesis of the core evidence base (N = 63). Regenerative potential is operationalised as credible only where supported by explicit ecological, socio-spatial, governance-related, or performance-oriented evidence, including life-cycle assessment, post-occupancy evidence, ecological monitoring, habitat enhancement, blue-green infrastructure integration, or documented implementation mechanisms. The findings show that floating typologies dominate the evidence base, whereas amphibious approaches are less frequent but more directly associated with in-place flood adaptation. Persistent gaps concern regulatory frameworks, infrastructure interfaces, life-cycle assessment, ecological validation, and long-term post-occupancy monitoring. The review concludes that scalability depends on context-specific siting, institutional permission, regulatory approval, and verifiable environmental performance. Full article

The chlorophyll-a (chl-a) concentration is a major indicator of marine ecosystem status, harmful algal blooms, and marine primary productivity. In coastal waters, however, complex hydrodynamic and ecological conditions lead to highly variable chl-a dynamics, driven by diverse and interacting mechanisms, posing substantial challenges for chl-a forecasts. To assess the applicability of machine learning approaches in predicting chl-a under complex coastal environments, we present a case study in the Taiwan Strait, where harmful algal blooms occur a few times every year. Based on satellite remote sensing data, a spatiotemporal imputation and prediction framework (STIMP), temporal models (Transformer, CrossFormer, Tsmixer), and spatiotemporal models (MTGNN and PredRNN) were applied to simulate chl-a spatiotemporal variability. A hydrodynamic–biogeochemical model was compared with these machine learning approaches to assess the model skills in coastal chl-a simulations. Results indicate that machine learning models trained with satellite data exhibit reasonable predictive skill offshore with pronounced seasonal variability and low data missing ratio, while their performance weakens in regions where seasonal signals are masked by short-term chl-a fluctuations with more missing data. In contrast, the hydrodynamic–biogeochemical model represents short-term variations in chl-a in nearshore regions with higher temporal resolution and accounts for the underlying mechanisms of phytoplankton biomass accumulation and die-off. When trained with model output, the machine learning approach shows improved performance in coastal chl-a forecasts, with much higher computational efficiency compared to the hydrodynamic–biogeochemical model. This study highlights the advantage of mechanistic and machine learning models in deciphering the spatiotemporal scales and governing mechanisms of chl-a variability in coastal regions and extracting spatiotemporal variability with computational efficiency, respectively. With input data of sufficient temporal resolution (e.g., daily to 3 days) and duration (5–10 years), a combination of the machine learning and mechanistic modeling approaches is recommended for operational coastal phytoplankton bloom forecasting. Full article

Microplastics (MPs, plastic particles < 5 mm) and nanoplastics (NPs, plastic particles generally <1 µm), collectively referred to as micro/nanoplastics (MNPs), have emerged as critical contaminants in wastewater systems due to their persistence, small size, and ability to act as vectors for co-contaminants. Conventional wastewater treatment technologies are often insufficient for the effective removal of microplastics, particularly for smaller particles and nanoplastics, necessitating the development of functional materials and innovative treatment strategies. In this review, recent advances in carbon-based materials, cellulose-based materials, and their hybrid carbon–cellulose composites for microplastics removal are critically analyzed and comparatively discussed. Particular attention is given to the structure–function relationships governing adsorption performance, including the roles of hierarchical porosity, surface chemistry, and interfacial interactions. The key mechanisms responsible for microplastics capture—such as hydrophobic interactions, π–π stacking, hydrogen bonding, electrostatic attraction, physical entrapment, and pore trapping—are systematically discussed. Carbon–cellulose composite materials are highlighted as a promising class of multifunctional adsorbents due to their synergistic combination of hydrophilic cellulose scaffolds and hydrophobic carbon domains. This dual functionality enables efficient removal of microplastics across a wide range of sizes and morphologies. Recent developments in magnetic and superhydrophobic composite systems further demonstrate enhanced separation efficiency, recyclability, and potential applicability in real wastewater environments. In addition to summarizing recent progress, this review critically examines the methodological inconsistencies, mechanistic uncertainties, and practical limitations associated with current adsorption systems. Despite significant progress, several challenges remain, including the lack of standardized evaluation methods, limited validation under real wastewater conditions, material stability issues, and scalability constraints. Future research directions are proposed, focusing on rational material design, sustainable carbon sources, multifunctional hybrid systems, and integration into existing treatment infrastructures. The development of sustainable hybrid adsorption systems for microplastics remediation also contributes to the achievement of Sustainable Development Goal 6 (Clean Water and Sanitation) by supporting improved wastewater treatment technologies and reduction in emerging aquatic contaminants. Full article

Freeze-induced damage in concrete is governed by complex interactions between pore-scale phase transition and macroscopic mechanical response, while the underlying pore structure is typically difficult to observe directly. This study proposes an integrated framework for porosity inversion in concrete under freeze–heaving conditions, combining mechanical modeling, finite element simulation, and deep learning. A mechanics-based model is first developed to describe frost-heaving behavior in porous concrete, accounting for elastoplastic deformation of the matrix and partial volumetric expansion induced by pore water freezing. Based on this formulation, a parametric finite element model with randomly distributed pores is constructed to generate datasets linking pore characteristics to full-field deformation responses. Building upon these physics-consistent data, a deep learning framework is established to reconstruct pore distribution directly from three-component strain fields. The model employs a Vision Transformer backbone to capture global deformation patterns and incorporates a Kolmogorov–Arnold Network-based nonlinear mapping to enhance representation of the highly nonlinear inverse relationship. The results demonstrate that the proposed approach achieves accurate pore reconstruction and porosity prediction with stable convergence and satisfactory generalization performance across different porosity levels. The study provides a physically interpretable and computationally efficient pathway for linking deformation fields to internal pore structure, offering new potential for non-destructive characterization and durability assessment of concrete in cold-region environments. Full article

Water-soluble viscosity-modifying admixtures (VMAs) were initially introduced into cementitious materials to enhance cohesion, stability and resistance to bleeding and segregation. With the development of self-compacting concrete, underwater concrete, grouting materials and 3D-printed cementitious materials, VMAs have become increasingly important for regulating rheological behavior, workability retention, shape retention and construction processability. Recent studies further indicate that VMAs can affect not only fresh-state properties, but also hydration kinetics, early-age microstructure evolution, mechanical performance, transport behavior and long-term durability. This review systematically summarizes the types, action mechanisms, and performance effects of water-soluble VMAs in cementitious materials. Particular emphasis is placed on the relationships among the molecular structure, liquid phase viscosity enhancement, particle adsorption and bridging, polymer-chain entanglement, ion-responsiveness, admixture compatibility, and microstructure evolution. The review shows that the effects of VMAs are not governed solely by admixture type or dosage, but depend strongly on molecular mass, functional groups, substituent composition, charge characteristics, binder chemistry, and the pore solution environment. Finally, current research gaps and future directions are discussed, including quantitative structure–mechanism–performance relationships, applicability in low-carbon binders, service-life prediction, and application-oriented VMA design. Full article