Environmental Progress & Sustainable Energy最新文献

Cupola furnace slag (CFS) poses significant challenges for casting industrialists, who must navigate the complexities of its disposal to maintain operational efficiency and environmental responsibility. This study aims to investigate and implement the reuse of CFS in the construction industry which in turn creates a new method for solid waste management. This study clarifies the mechanical and durability properties of concrete that contains CFS-coarse-aggregates (CCA) and cupola-fine-aggregates (CFA), which are natural fine and coarse aggregate substitutes. To accomplish this, compressive strength, split tensile strength, water penetration, impact resistance, surface abrasion loss, and rapid chloride penetration tests were conducted. In M30 grade concrete, the experimental procedures involved varying degrees of weight replacement (0% to 40%) of natural fine-aggregate (FA) and natural coarse-aggregates (CA) with CFA and CCA, respectively. The experimental findings revealed that compressive strength increased with up to 20% replacement of FA, but decreased afterward. Conversely, compressive strength decreased with the replacement of CA, though up to 30%, replacement still met M30 grade concrete requirements. A leachability test was conducted to detect toxic and heavy materials in CFS. SEM, EDX and XRD techniques were also employed. Replacing FA and CA with CFA and CCA, respectively, proved economically beneficial compared to standard concrete.

Solar energy has been a clean and renewable resource that offers a promising solution for water harvesting. Herein, a double slope solar still (DSSS) unified with an external condenser and internal heater was fabricated and tested to enhance freshwater production rates under Malaysian climate conditions. The integrated model was designed to operate both day and night, and its productivity was compared with that of a passive still. The study outcomes revealed that the average increment in the daily production rate of the active still was 56% during the daytime and 510% during the nighttime compared to the passive one. When calculating the cumulative production rates over the five days of the field experiment, the active still demonstrated a notable increase in productivity, reaching approximately 159% as compared to the passive one. This resulted in total production rates of 34.14 and 13.20 kg/m² from the active and passive stills, respectively. Compared to the passive still, the active still had a lower relative humidity due to the external condenser. Additionally, the factors such as water and ambient temperatures and solar radiation intensity significantly impact daily distillate output at which strong correlations were observed between these parameters. Finally, the product water demonstrates a significant improvement in desalinated water quality, meeting safety standards outlined by the World Health Organization (WHO).

The valorization of eggshell waste as a sustainable biofiller offers a promising approach to improve the mechanical properties of biocomposites while addressing environmental concerns. In addition to reducing landfill accumulation, eggshell powder, which is high in calcium carbonate, also acts as a functional hybrid reinforcement in composites made of polymers. At the same time, cigarette butts are the most common litter in the world. They release dangerous pollutants, including hydrogen cyanide, acetaldehydes, heavy metals, and polycyclic aromatic hydrocarbons, which linger in the environment and seriously endanger both aquatic and terrestrial life. Using duck eggshell powder (DEP) as a bio filler, the mechanical behavior of vinyl ester composites reinforced with silane-treated palm fruit fibers (STP) and smoked cigarette filter fibers (CFF) is optimized in this study. Compression molding was used to create hybrid composites with different eggshell powder loadings (0%, 2%, and 4%). The Criteria Importance through Inter-Criteria Correlation (CRITIC) method and the Evaluation Based on Distance from Average Solution (EDAS) methodology were used in an integrated multi-criteria decision-making (MCDM) framework to identify the best formulation. With a tensile strength of 49.71 MPa, flexural strength of 37.88 MPa, and impact strength of 38.67 J/m, the CP9 composite (CFF 40 weight percent + STP 40 weight percent + eggshell powder 2 weight percent) outperformed the other manufactured samples in terms of mechanical qualities. The experimental findings and hybrid optimization analysis verify that eggshell-incorporated bio-composites, especially CP9, exhibit improved mechanical performance and have a great deal of promise for environmentally friendly, sustainable applications.

To mitigate selenium (Se) stress in Cyphomandra betacea, the effects of salicylic acid (SA) on the growth and Se absorption of C. betacea seedlings under Se stress were investigated in this study through a pot experiment. SA was found to enhance the biomass of various organs in C. betacea seedlings, with the optimal concentration being 150 mg/L. Compared to control, the concentration of 150 mg/L SA resulted in a 52.55% increase in root biomass and a 37.68% increase in shoot biomass. Additionally, SA was found to increase the levels of photosynthetic pigments, net photosynthetic rate, transpiration rate, stomatal conductance, and intercellular CO₂ concentration of C. betacea seedlings. SA also led to an increase in the antioxidant enzyme activity and soluble protein content of C. betacea seedlings. Furthermore, SA increased the Se contents in various organs of C. betacea seedlings, with the most effective concentration being 150 mg/L. At this concentration, the contents of root Se and shoot Se increased by 29.74% and 30.69%, respectively, compared to control. Correlation and gray relational analyses indicated that the chlorophyll b content, net photosynthetic rate, and shoot biomass were the most closely related to the shoot Se content. In conclusion, SA can effectively mitigate Se stress in C. betacea, and promote its growth and Se absorption, with the most effective concentration being 150 mg/L.

Rapid urbanization in the Nordic region has intensified municipal solid waste (MSW) accumulation, straining waste management systems and contributing to ecosystem pollution through expanded transportation and industrial activities. This study investigates the effects of waste recycling, MSW, environmental taxes, and urbanization on the ecological footprint in the Nordic countries from 1995 to 2021. Employing second-generation unit root tests, slope homogeneity analysis, and panel cointegration tests, followed by quantile regression, the results reveal that economic growth, MSW, and urbanization increase the ecological footprint, while higher recycling rates reduce it. Environmental taxes exert a mitigating effect on the ecological footprint primarily at higher quantiles. Robustness checks using Driscoll-Kraay standard errors (DKSE), panel-corrected standard errors (PCSE), and system generalized method of moments (GMM) confirm these findings. Dumitrescu-Hurlin (D-H) causality tests indicate bidirectional relationships between MSW and the ecological footprint, recycling rates and the ecological footprint, and urbanization and the ecological footprint. These insights provide valuable guidance for policymakers advancing sustainable development goals (SDGs) in the Nordic region.

This study addresses key research gaps in diesel engine-based combined heat and power (CHP) systems by presenting the very first overall Energy, Exergy, Economic, and Environmental (4E) investigation of compression ratio optimization. Unlike previous research, this research uniquely demonstrates that optimization of the in-built compression ratio in diesel-CHP systems can alone result in significant efficiency, economic, and environmental improvements. This novel 4E analysis and optimization approach opens up a new design pathway via quantification of multi-objective trade-offs of compression ratio modulation, thereby advancing CHP system design beyond peripheral retrofits. It has been demonstrated that raising the compression ratio (14:25) elevates engine power output by 44% and recoverable heat, to as much as 89.5% CHP efficiency. These advantages are realized, however, at severe costs: 6.8% more exergy destruction and 10.3% less carbon emission savings (CDER). To mitigate these trade-offs, a novel multi-objective genetic algorithm framework was developed with normalized objectives. Optimization returns cr = 20.11 as the Pareto-optimal solution, trading off 89.13% CHP efficiency, 0.2469 $/kWh energy cost, moderated exergy destruction (44.7 kJ/kg), and sustainable CDER (0.2389). Above all, the Pareto frontier delineates actionable design regimes: sustainability-focused applications favor cr = 14–18.89 (high emission reduction), while efficiency-focused systems operate at cr = 20.11–25 (peak η_CHP).

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.