Environmental Progress & Sustainable Energy最新文献

This work investigated the phase composition and structural properties of spent bleaching earth, a harmful waste material used for filtering edible oil. The phase composition and structural properties were investigated through heat treatment from room temperature to 1000°C, using X-ray diffraction with Rietveld refinement. The findings revealed that spent bleaching earth contains montmorillonite, β-tridymite, β-cristobalite, α-quartz and aluminosilicates. Also, it was determined that the oil remnant from the industrial process is strongly adhered to the amorphous silica and plays a critical role during the phases' recrystallization. Results show a complex phase evolution as the calcination temperature increases. Montmorillonite partially decomposes above 900°C into aluminosilicates and tridymite transforms to cristobalite. Furthermore, aluminosilicates of the type Al₂SiO₅ are promoted when the temperature is higher than 1000°C. This behavior is explained by the interactions between organic and inorganic components. The structural changes endow the spent bleaching earth with new and interesting properties, making it a promising candidate for the building industry.

Herein, mesoporous TiO₂ photocatalysts doped with different amounts of Sn ions were successfully designed and synthesized by the hydrothermal method. The characterization results show that TiO₂ transforms from the anatase phase to the rutile phase after Sn ion doping. The particle size is slightly smaller than that of mesoporous TiO₂ with the Sn element uniformly distributed. It is worth noting that the Sn(2)-TiO₂ samples exhibit mesoporous pores with diameters ranging from 10 to 30 nm, a high specific surface area of 55.657 m²·g⁻¹, and abundant oxygen vacancies. Furthermore, the Sn(2)-TiO₂ sample exhibits the lowest fluorescence intensity. Compared with TiO₂, the absorption edge of Sn(2)-TiO₂ redshifts the most, and it has the strongest absorption and response to visible light, minimizing the band gap of the sample to the greatest extent. The effects of Sn doping amount on the photodegradation efficiencies using florfenicol antibiotics were studied. The photocatalytic degradation performance of the Sn(2)-TiO₂ sample was 2.08 times that of mesoporous TiO₂ with a first-order reaction feature. The apparent activation energy of the Sn(2)-TiO₂ sample is estimated to be 26266.92 J mol⁻¹. The four-cycle cyclic photodegradation experiments further confirmed the photocatalytic stability and reusability of the Sn(2)-TiO₂ samples. The above results indicate that the introduction of a mesoporous structure and the doping of Sn ions can effectively enhance the performance of TiO₂ samples in the photodegradation of antibiotics.

Innovative approaches are becoming increasingly important in the management and treatment of microplastics and nanoplastics (MNPs). However, many emerging strategies face challenges such as complex synthesis and modifications, high costs, and the risk of secondary pollution, limiting their practical applications. Recently, sustainable strategies utilizing natural products have been explored for microplastic removal, leading to the development of various materials, including sponges, gels, emulsions, floccules, enzymes, and microorganisms. These materials not only address the limitations of conventional methods but also offer advantages such as simple preparation, low-cost, and enhanced safety. This work begins by discussing the presence of MNPs in common food resources, followed by an overview of their pathways into the human body. The review then explores the development of sustainable materials and methods for MNPs elimination, with a focus on their mechanisms, functionalities, advantages, and limitations. Finally, attention is given to public policy directions, future scientific challenges, and opportunities, aiming to inspire further research and practical applications.

The addition of phase change materials (PCM) to geo polymer mortar (GPM) is a promising advance in the pursuit of ecologically benign and energy-efficient construction materials. This review looks at the synthesis, characterization, and performance of GPMs, with a particular emphasis on the consequences of adding PCMs. The review emphasizes the growing global demand for energy-efficient construction solutions and discusses the critical role of geo polymer mortar in meeting this demand. It also addresses the synergy between PCM and GPM, revealing the principles underlying PCM's latent heat storage capacities and the geo polymer's ability to operate as a stable and durable matrix. Major findings show that PCMs considerably improve the thermal characteristics of GPMs by increasing heat capacity and decreasing thermal conductivity. In addition to boosting durability and thermal resilience, the energy-storing PCM and the strong GPM combo increase long-term performance. The PCM incorporated GPM improves thermal energy storage capacities; energy savings of up to 30% for cooling and 15% for heating. However, the addition of PCMs often results in a minor drop in mechanical performance, particularly compressive strength. Although the mortar is weak due to the development of air spaces and weak connections between the PCM capsules and the mortar matrix the strengths are within acceptable limits. Future study is needed to improve long-term performance and endurance in demanding real-world environments. This comprehensive review will inspire further research, innovation, and adoption of this technology, thereby contributing to a greener and more energy-efficient built environment.

In this experimental analysis, the impacts of altering the injection nozzle geometry on the performance parameters of a compression ignition (CI) engine were explored. The injection nozzle geometry of the standard engine with three holes of 0.24 mm diameter was replaced by a 6-hole injector having 0.20 mm diameter. The modified engine was tested by a blend of 20 volume per cent of jatropha biodiesel (JOME20) in diesel. Considering the small size of the injector orifice, the injection pressure was raised to 240 bar from the standard pressure, and the injection timing was adjusted to 21° before Top Dead Center (bTDC) from the normal. The test findings revealed that the modified engine showed an enhancement in “Brake Specific Fuel Consumption (BSFC)” and “Brake Thermal Efficiency (BTE).” Notable improvements in the decrease of emissions have been observed. However, the enhanced fuel-air mixing and high combustion temperature increased the oxides of nitrogen (NOx) emissions. The modification of the injection nozzle geometry showed improvements in BSFC, BTE, and a reduction in emissions, but with a trade-off of increased NOx emissions, highlighting the need for further optimization.

This study presents a sustainable approach to the production of lightweight ceramsite from industrial by-products, specifically tungsten tailings and fly ash. By integrating these materials with a foaming agent, we successfully synthesized ceramsite with reduced bulk density and improved strength, making it suitable for various applications such as construction. Through orthogonal experiments, we got the best ceramsite, which exhibited a compressive strength of 19.45 MPa, water absorption of 7.63%, and a bulk density of 0.925 g/cm³. Additionally, the incorporation of sawdust or stearic acid allowed for the adjustment of ceramsite density, producing a range of products with densities from 700 to 1000 kg/m³. The ceramsite complied with standards, exhibiting minimal heavy metal ion leaching. Crystal phase composition and mineral changes during sintering were analyzed, along with microstructure changes affecting ceramsite properties.

This study investigates the catalytic epoxidation of soybean oil utilizing a hybrid oxygen carrier through an in situ peroxy acids mechanism, aiming to optimize the process for enhanced relative conversion oxirane as lack of studies reported usage of hybrid oxygen carriers to date. As environmental concerns rise, the utilization of sustainable feedstocks like soybean oil presents a promising alternative to petroleum-based sources. Through systematic optimization, we identified the optimal conditions for achieving a maximum oxirane conversion of 54%. Key parameters included the use of sulfuric acid as a catalyst, a reaction temperature of 80°C, and a stirring speed of 400 rpm. This work not only underscores the potential of soybean oil as a valuable feedstock for producing epoxides but also highlights the advantages of using hybrid oxygen carriers to enhance reaction efficiency while minimizing environmental impact. Lastly, numerical simulations were executed employing a genetic algorithm in MATLAB R2023A, and the outcomes exhibited a good agreement between the simulated data and the empirical observations where R² was recorded as 0.92 with kinetic constants k₁₁ = 0.50 (M min)⁻¹, k₁₂ = 39.94 (M min)⁻¹, k₂ = 7.44 (M min)⁻¹, k₃ = 0.12 (M min)⁻¹.

Unaccounted-for Gas (UFG) in city gas distribution networks presents critical economic and environmental challenges. This review explores the causes, detection methods, and mitigation strategies of UFG. Key causes include measurement errors, leakage, theft, and unreported usage, all contributing to inefficiencies and higher costs for gas companies and consumers. Additionally, UFG exacerbates methane emissions, a potent contributor to climate change. Advanced detection technologies, such as metering infrastructure, leak detection systems, and data analytics, are examined for their effectiveness. The study also addresses regulatory frameworks and industry standards essential for UFG management. Mitigation strategies include enhanced pipeline maintenance, sophisticated monitoring systems, and theft prevention measures, alongside fostering transparency and accountability within the industry. This review aims to provide a comprehensive understanding of UFG challenges and solutions, emphasizing the need for innovative approaches to reduce its economic and environmental impacts, contributing to more sustainable city gas distribution networks.

This study explores the performance of a building integrated semitransparent photovoltaic system enhanced with movable insulations, a thermal mass, and a south-facing window focusing on its application in cold climatic conditions at a conceptual level. The system's electrical energy production, thermal gains, and daylight savings are assessed, with particular attention to the thermal conductivity, thickness, and configuration of movable insulations. A new daylight savings equation, integrating both roof and window contributions, showed a 72.66% improvement over previous approaches that neglected the contributions of the south-facing window. Comparative simulations revealed that applying movable insulation only during off-sunshine hours effectively prevents nighttime heat loss while avoiding daytime overheating. Additionally, optimizing the number of air changes from N = 1 to N = 5 reduced peak indoor temperatures from 40.88°C to 24.45°C, enhancing thermal comfort. The results confirm that decreasing U-values from 8.36 to 2.902 W/m²°C directly correlates with improved insulation performance, leading to greater energy efficiency and occupant comfort.

This study investigates the assessment of the water quality and microbial quality of the Nile River water within the Beni-Suef governorate in Egypt. Twenty water samples were collected seasonally from Autumn 2023 to Summer 2024. The findings showed a significant increase in nitrate, ammonium, and orthophosphate concentrations, especially in the vicinity of agricultural drainage points. Place, season, and inter-group interactions were attributed to the significant differences seen in the analysis of variance for all bacterial groups. Canadian Council of Ministers of the Environment-water quality index was used to assess each location's overall water quality. The majority of physicochemical characteristics were found to be within allowable bounds for irrigation, drinking water, and the protection of aquatic life. Extreme caution is advised in the Beni-Suef governorate's River Nile, even though the levels of water contamination are below WHO-acceptable thresholds. To preserve this essential water resource, recommendations include implementing sustainable agricultural practices, enforcing stronger regulations on polluting sources, and launching public awareness initiatives. These precautions include limiting the excessive use of organic fertilizers, establishing pollutant industries, and avoiding the use of wastewater and sewage sludge in agriculture.