Search Results (3,159)

The incorporation of bio-derived modifiers in bitumen binders presents a practical pathway toward sustainable, carbon-sequestering road pavement infrastructure. This study evaluates commercially produced ECHO2 softwood biochar as a modifier for Australian viscosity-graded C170 bitumen, combining microstructural, thermal, physical, and rheological characterization to assess its suitability as a high-temperature reinforcing modifier. In this study, biochar was incorporated at 3%, 6%, 9%, and 12% by weight, utilizing particles smaller than 75 µm to maximize interfacial interaction. Characterization via SEM-EDS, XRD, and TGA revealed a highly stable, carbon-rich, amorphous material with a rough, porous morphology, favourable for physical interlocking with the bitumen matrix. Physical and rheological investigations demonstrated that ECHO2 biochar measurably enhances binder stiffness and high-temperature deformation resistance. Compared with the control, 12% biochar modification reduced penetration by approximately 27% and increased the softening point by approximately 10%, indicating a reduction in temperature susceptibility. Dynamic shear rheometer (DSR) temperature sweeps highlighted substantial increases in the complex shear modulus (G*) and rutting factor (G*/sinδ) without altering the phase angle (δ), confirming the modifier acts as a rigid, particulate reinforcing agent rather than an elastomer. Multiple stress creep recovery (MSCR) testing supported these findings; non-recoverable creep compliance (J_nr) decreased progressively. Critically, under the AASHTO M 332 specification, while the neat bitumen binder barely met the standard traffic (S) criteria, the progressive reduction in J_nr (particularly at 12%) delivered a substantially higher factor of safety against rutting within the standard traffic designation. Finally, ECHO2 biochar demonstrates strong potential as a sustainable modifier that restricts viscous flow through particulate stiffening, enhancing high-temperature rutting resistance at elevated temperatures. Full article

Food industry wastewater containing synthetic dyes threatens ecological safety and human health. Therefore, efficient and environmentally friendly adsorbents that can remove synthetic food dyes from wastewater are urgently needed. In this work, a self-nitrogen-doped biochar (GSNBC), used for adsorption of food dyes including carmine and tartrazine, was facilely prepared by employing ginger straw waste as the carbon precursor and NaHCO₃ as a mild and relatively benign pore-forming agent via one-step pyrolysis. The as-prepared GSNBC featured well-developed porous structures, a specific surface area of 1712.52 m² g⁻¹, and rich oxygen- and nitrogen-containing functional surface groups. Particularly, GSNBC performed ultrafast adsorption, with approximately 90% of the equilibrium capacity within 1 min (600.13 mg g⁻¹ and 580.24 mg g⁻¹ for carmine and tartrazine, respectively), and reached adsorption equilibrium at about 10 min. In addition, it exhibited excellent regenerability. The adsorption kinetics and isotherms fit well with pseudo-second-order and Langmuir models. DFT calculations indicated that π–π stacking and hydrogen bonding were mainly responsible for the adsorption. This study presents not only a promising and efficient adsorbent for the remediation of dye-laden food industry wastewater but also a sustainable route for the resource utilization of ginger straw waste. Full article

Biochar is a porous, carbon-rich soil amendment that can enhance soil water retention capacity by modifying pore structure and physicochemical properties. Understanding the soil−water characteristic curve (SWCC) of biochar-amended soils is essential for evaluating their hydrological behavior and promoting the application of biochar in engineering practice. Given the demonstrated feasibility and accuracy of machine learning methods for predicting soil parameters, this study employed six machine learning models, namely, decision tree, random forest, XGBoost, LightGBM, CatBoost, and artificial neural network, to predict the SWCC of biochar-amended soils based on a constructed dataset. Feature importance analysis and partial dependence analysis were further conducted to reveal the influence patterns of key variables. The results indicate that all six models exhibit good predictive capability, with gradient boosting models (XGBoost, CatBoost, and LightGBM) performing best. Suction is the dominant factor controlling the volumetric water content variation, while soil particle-size distribution and dry density provide the physical basis for water retention. Biochar content, pyrolysis temperature, and feedstock type further modulate the water retention capacity of amended soils. Overall, the findings demonstrate that machine learning approaches can effectively predict the SWCC of biochar-amended soils and provide insights into the controlling mechanisms of soil water retention. Full article

In this study, a MIL-100(Fe)@KTBC composite was successfully fabricated via an in situ hydrothermal method using KOH-activated tomato-biochar-derived carbon (KTBC) as the support, and was applied for the efficient adsorptive removal of xylenol orange (XO) from water. Characterization by SEM, XRD, FTIR, XPS, and BET confirmed that MIL-100(Fe) was successfully loaded onto the KTBC surface, and the resulting composite exhibited a well-developed porous structure, abundant functional groups, and good thermal stability. Adsorption experiments showed that MIL-100(Fe)_0.5@KTBC delivered the optimal performance, with a maximum adsorption capacity of 246.12 mg/g; high removal efficiency was achieved at pH 4.0 and an adsorbent dosage of 0.4 g/L. The adsorption process followed pseudo-second-order kinetics and the Langmuir isotherm model, indicating spontaneous, endothermic, monolayer adsorption dominated by chemisorption. The composite also demonstrated strong resistance to interfering ions and favorable reusability. This work provides a scientific basis for the development of efficient and stable biochar-based MOF composites for the treatment of printing and dyeing wastewater. Full article

In this work, three biochars were synthesized from a mixture of an abundant agricultural waste (date palm fronds) and an animal biomass (chicken manure) at pyrolysis temperatures of 700 °C (B-700), 800 °C (B-800), and 900 °C (B-900), respectively. These biochars were characterized and used as electrode materials in a capacitive deionization (CDI) process to remove salts from saline water. The CDI results show that the B-700 electrode displayed the highest desalination efficiency of 10.2% with 100 ppm NaCl. Further mixing the B-700 with 10% and 20% of multi-walled carbon nanotubes (CNT) revealed an enhanced desalination performance. For instance, a biochar-20%CNT electrode achieved a salt adsorption capacity (SAC) of 11.32 mg/g at 200 ppm NaCl, which is 7.6 times higher than that of B-700 alone. The performance enhancement is attributed to carbon nanotubes acting as conductive channels between biochar particles, thereby improving electrical conductivity and electrochemical properties of the CDI electrode. Additionally, the presence of well-known hydrophilic functional groups on CNT surfaces enhances hydrophilicity, providing a highly porous surface area. The results suggest that the CDI method with biochar–CNT electrodes offers opportunities for energy-efficient, low-cost freshwater production, with significant scaling up potential for the treatment of brackish and wastewater. Full article

The demand for a versatile and portable point-of-use (POU) sensor platform has surged due to the pandemic, especially in countries with limited medical laboratory facilities. We recently unveiled a portable, non-planar, interdigitated, flow-through, porous electrode platform that automatically measures electrochemical impedance spectroscopy (EIS) signals from various biomarkers. However, the packed powder exhibited a loss of performance over time due to displacement, leaching, and poor stability. Herein, we modified the packing strategy by synthesizing the sensing material within the channel, thereby improving adhesion, structural integrity, and stability. Leveraging the exceptional thermal stability, mechanical strength, and chemical resistance of polyimide (PI), we developed a novel fabrication approach that combines liquid-phase inversion and breath-figure techniques to create a porous PI manifold with single-walled carbon nanotubes (SWCNTs) under varying humidity conditions. Scanning electron microscope (SEM) analysis revealed that lower relative humidity (RH) conditions yield larger but less uniformly distributed pores, leading to increased channel pressure. The manifold demonstrated exceptional stability under rigorous flow conditions, withstanding a high flow rate of 30 µL/min while maintaining consistent pressure-EIS responses. The device produced a measurable proof-of-concept impedance response following exposure to a femtomolar concentration of complementary target ssDNA in 1× PBS within 15 min. A formal limit of detection was not determined in the present study. We developed a mechanically stable sensor design with improved durability under repeated flow conditions by systematically optimizing synthesis conditions and manifold configuration. This innovative fabrication strategy demonstrates the importance of packing methodology in sensor design and paves the way for robust, scalable, and efficient diagnostic solutions in resource-limited settings. Full article

Carbon fiber (CF)-reinforced polyethylene (PE) composites have low density, outstanding corrosion resistance and good processability. These materials are widely promising for household appliances, automobiles and construction industries. Nevertheless, PE is a non-polar inert matrix with extremely low surface energy, leading to poor interfacial wettability and bonding force with CF. Interfacial debonding frequently occurs along with low load transfer efficiency, failing to meet the service requirements of high-performance structural components. In this study, CF was carboxylated with hydrogen peroxide, and Cu-BTC porous materials were in situ grown on the fiber surface to obtain modified CF (CF-Cu-BTC). The CF-Cu-BTC was then incorporated into a low-density polyethylene (LDPE) matrix. The MOF layer improves the interfacial compatibility and bonding force between the fibers and the matrix and enhances the overall mechanical properties and structural stability of the composites. The mechanical performance of CF composites is remarkably superior to that of pure LDPE. Compared with the pristine sample with a tensile strength of 11.04 MPa, the composite exhibits an enhanced tensile strength of 26.63 MPa, an increase of 141.20%. Scanning electron microscopy results confirm that no gaps exist between the CF and LDPE, verifying favorable interfacial compatibility. MOF-modified CF effectively improves the mechanical properties of resin-based composites. This study provides practical guidance for advanced composite applications. Full article

The development of sustainable and efficient adsorbent materials for tetracycline hydrochloride (TCH) removal is of great importance for wastewater treatment. Structural characterizations (XRD and FTIR) confirmed successful lignin carbonization and the abundance of oxygen-containing functional groups, while N₂ physisorption revealed a phosphoric acid-induced hierarchical porous structure rich in mesopores to facilitate mass transfer. CL exhibited excellent tetracycline hydrochloride (TCH) adsorption, achieving a maximum capacity of 21.06 mg g⁻¹ within 2 h. The adsorption data closely followed the pseudo-second-order kinetic model, indicating a predominantly chemisorption process. While nanocellulose enabled the fabrication of flexible, self-supporting films with well-dispersed CL, excessive loading deteriorated film integrity. An optimized 30 wt% CL content achieved the ideal balance between structural stability and adsorption performance, demonstrating that these sustainable films hold great potential for aquatic antibiotic remediation. Full article

Aluminum metallic foams are lightweight porous materials characterized by low density, high stiffness, and remarkable energy absorption capacity. The mechanical performance of these materials strongly depends on the microstructure of the metallic matrix and the porous structure. In this study, closed-cell A356 aluminum foams were produced by the Alporas melt-foaming method using barite (BaSO₄) as a thickening agent and calcium carbonate (CaCO₃) as a foaming agent. The effect of grain refinement on the microstructure and energy absorption behavior under quasi-static compression was investigated. Grain refinement was evaluated by adding four concentrations of Al-5Ti-1B master alloy (0.02, 0.05, 0.08, and 0.10 wt.%) to the unrefined foam. The addition of Al-5Ti-1B reduced the secondary dendrite arm spacing (SDAS) from 41.85 µm to a minimum of 32.96 µm at 0.05 wt.%, producing stronger and more homogeneous cell walls that increased the plateau stress from 0.525 to 1.549 MPa and the energy absorption capacity from 0.299 to 0.735 MJ/m³—improvements of 195% and 145%, respectively. The energy absorption efficiency analysis confirmed that any refiner concentration improved the compressive performance compared to the unrefined foam. In addition, the energy absorption efficiency (E) and the ideality energy absorption efficiency (I) confirm that the refinement of the dendritic structure through Al-5Ti-1B addition strengthens the foam cell walls, improving their mechanical behavior and performance as an energy-absorbing material under quasi-static compression. Full article

The growing demand for sustainable construction materials has encouraged the development of waste-based alkali-activated foams (AAFs) with enhanced thermal performance. This study investigates the use of roof tile waste (RTW) and marble waste (MW) for producing lightweight AAFs and evaluates the influence of aluminum (Al) powder on material performance. The novelty of this study lies in combining binder optimization, systematic evaluation of Al-induced pore evolution, and quantitative sustainability assessment within a single experimental framework. RTW was partially replaced with MW to optimize the binder, followed by the incorporation of Al powder (0–0.20 wt%) as a foaming agent. In an alkaline medium, metallic Al released H₂ gas, generating the porous structure of the AAFs. Physical, mechanical, thermal, microstructural, and material-based environmental properties were evaluated. In the binder optimization stage, 30% MW increased the compressive strength from 5.57 to 15.50 MPa. During AAF production, increasing Al content reduced dry-state thermal conductivity from 0.99 to 0.09 W/m·K, although excessive Al promoted pore coalescence and strength loss. The optimum 70RTW:30MW:0.15Al mixture exhibited a unit weight of 0.56 g/cm³, a dry-state thermal conductivity of 0.15 W/m·K, a compressive strength of 3.12 MPa, 79.9% waste incorporation, and 65.9% lower material-based embodied carbon than an ordinary Portland cement (OPC)-based reference binder, demonstrating its suitability for lightweight non-loadbearing wall applications. Full article

Against the backdrop of China’s dual-carbon strategy and the development of green transportation, systematic research on direct pavement carbon absorption and sequestration remains limited. Traditional epoxy resin coatings, owing to their dense structure, poor air permeability, and single functionality, fail to meet the requirements for pavement carbon absorption. To address this issue, an ordered, honeycomb-like, porous epoxy carbon-absorbing coating was prepared using bisphenol A epoxy resin as the matrix and diethylenetriamine as the curing agent through the breath-figure method. The pore-formation mechanism and the process regulation principles of the coating were systematically elucidated. Key preparation parameters (ambient humidity, dispersion concentration, and spray dosage) were regulated, and multiple microscopic characterization methods, including SEM, FTIR, and TG, were adopted to comprehensively explore the influences of preparation parameters on the coating’s microstructure, chemical composition, and thermal stability. Experimental results indicate that under optimized process conditions, a honeycomb-like porous coating with uniform pore size and regular arrangement can be fabricated. The fabrication procedure features simple operation, favorable controllability, and low cost. The breath-figure method was successfully applied to the preparation of a porous epoxy carbon-absorbing coating, achieving controllable regulation of the porous structure and thereby effectively overcoming the limitations imposed by the dense nature of traditional epoxy coatings. Consequently, this work provides new technical concepts and data support for the development and application of low-carbon functional coatings for pavements. Full article

Metal–organic framework (MOF)-derived materials have recently emerged as promising sensing materials because of their tunable composition, porous architecture, high surface area, and defect-rich structures. Therefore, MOF-derived materials have significantly attracted the scientific community to design and fabricate triethylamine (TEA) gas sensors. TEA is a toxic, volatile, and malodorous amine that is widely released from industrial processes, food spoilage, and environmental sources. The selective and sensitive detection of TEA is of great importance for health, safety, and environmental monitoring. Previous years have witnessed rapid growth in the development of MOF-derived materials based on TEA gas sensors. This review critically evaluates recent progress in the fabrication of MOF-derived metal oxides, mixed-metal oxides, doped systems, noble-metal-functionalized materials, carbon-containing composites, MXene-integrated architectures, and heterojunction-based TEA gas sensors. The response, selectivity, stability, and sensing mechanisms for TEA gas sensors are discussed. Furthermore, challenges and perspectives are discussed. We believe that this review may be beneficial for those actively working in the fabrication of MOF-based TEA gas sensors. Full article

Geological storage of carbon dioxide (CO₂) in deep-sea formations represents a pivotal strategy for mitigating atmospheric CO₂ levels, where storage security and efficacy are fundamentally governed by the pore-scale seepage behavior of CO₂. However, the microscopic displacement mechanisms of CO₂–water two-phase flow under the characteristic high-pressure, low-temperature conditions of the deep sea remain inadequately understood. This study employed a self-developed high-pressure microfluidic experimental platform (0–30 MPa, 4–50 °C) to systematically investigate the CO₂ displacement process in porous media. The effects of injection rate (0.001–5 mL/min) and system pressure (1, 5, and 10 MPa) on displacement patterns, front stability, and final saturation were quantified. The results demonstrate that injection rate is the primary controller of displacement stability: high rates (≥0.1 mL/min) induce viscous fingering and lower final saturation, whereas low rates (≤0.05 mL/min) promote stable, piston-like displacement. Crucially, elevated pressure exerts a profound stabilizing effect, effectively suppressing fingering instabilities and enhancing final gas saturation (up to 0.544 at 10 MPa). This work elucidates the synergistic regulatory mechanism between injection rate and confining pressure, providing essential pore-scale experimental evidence for optimizing injection parameters to achieve efficient and secure CO₂ storage in deep-sea reservoirs. Full article

The transition to low-carbon energy systems is expanding the use of subsurface resources for heat extraction, energy storage, carbon management, and infrastructure reuse. This review examines hydraulic fracturing as a context-dependent engineering intervention across enhanced geothermal systems, geothermal reuse of depleted reservoirs and wells, unconventional gas, underground hydrogen storage, CO₂-based subsurface engineering, and natural hydrogen. We synthesize how stimulation can improve permeability, connectivity, heat exchange, injectivity, and deliverability, while evaluating constraints related to water use, induced seismicity, leakage, well and caprock integrity, life-cycle emissions, and public acceptance. The central trade-off is that higher stimulation efficiency does not necessarily produce greater sustainability. Short-term gains in flow or energy delivery can increase long-term risks to containment, thermal performance, seismic safety, and environmental accountability. Evidence is strongest for enhanced geothermal systems and commercial unconventional gas, whereas field support remains limited for porous-media hydrogen storage, CO₂-based fracturing, and natural hydrogen. Responsible deployment therefore requires site-specific boundaries, real-time monitoring, multi-physics and data-driven modeling, life-cycle assessment, and adaptive governance. Hydraulic fracturing can enable selected sustainable subsurface applications, but its value depends on balancing engineering performance against long-term environmental and integrity constraints. Full article

The global crisis of expanded polystyrene (EPS) waste and the rising demand for affordable water purification technologies necessitate the development of sustainable, high-performance filtration materials. This study reports the successful upcycling of post-consumer Styrofoam into functional nanocomposite membranes reinforced with nano-activated carbon (nAC). Fabricated via nonsolvent-induced phase separation (NIPS) with nAC concentrations ranging from 0 to 0.4 wt.%, the membranes were evaluated to determine the synergistic effects of nanoparticle loading on morphology and transport phenomena. Scanning electron microscopy (SEM) revealed a stable asymmetric architecture characterized by a dense selective skin layer and a porous support structure. The integration of nAC significantly enhanced both surface hydrophilicity and structural porosity. The 0.3 wt.% nAC loading yielded optimal results, achieving a minimum water contact angle of 70.03° and a maximum porosity of 93.17%. Consequently, hydraulic permeability reached a peak of 35.66 LMH/bar, an approximate 223% improvement over the pristine EPS baseline. Performance evaluations utilizing Spirulina platensis as a model biomass demonstrated an absolute rejection efficiency of 100% and a turbidity reduction to 0 NTU across all composite variations, confirming robust size-exclusion capabilities. These findings demonstrate that incorporating nAC effectively transforms recycled Styrofoam into a high-value, sustainable filtration medium, offering a highly efficient and low-cost solution for cyanobacteria harvesting and environmental remediation. Full article