Search Results (369)

The swift global proliferation of solar photovoltaic (PV) technology has significantly contributed to the acceleration of the transition to renewable energy. Projections indicate a significant rise in installed capacity by 2050, suggesting that the extensive implementation of solar panels is transforming energy systems while simultaneously highlighting important issues regarding end-of-life waste management and long-term sustainability. The environmental advantages of photovoltaic (PV) systems are overshadowed by the prevalent reliance on landfilling and inadequate recycling practices, revealing a substantial deficiency in sustainable waste management, especially in areas with underdeveloped policy frameworks. This research study examines the solar panel supply chain, highlighting critical stages, sources of waste generation, existing management practices, and potential areas for enhancement. Waste is classified into four categories, solid, hazardous, electronic (WEEE), and environmental, each necessitating specific management strategies. Regions such as Europe exhibit comprehensive legal frameworks and advanced recycling technologies, whereas others, including Latin America and certain areas of Asia, continue to encounter deficits in policy and infrastructure. The research highlights the implementation of the 6R principles—Recycle, Recover, Reduce, Reuse, Repair, and Refine—within a circular economy framework to improve sustainability, optimize resource utilization, and reduce environmental impact. The findings highlight the necessity for coordinated policies, technological innovation, and international collaboration to ensure a sustainable future for solar energy. This study offers important insights for policymakers, industry stakeholders, and researchers focused on enhancing circularity and sustainability within the photovoltaic sector. Full article

The effective recovery of valuable materials from spent LiFePO₄ batteries is crucial for resource sustainability and environmental protection. This study investigates the recovery of phosphorus iron slag from waste LiFePO₄ batteries, focusing on dissolution and impurity removal processes to produce battery-grade iron phosphate. Using high-temperature-activated dissolution, followed by precipitation/dissolution for impurity removal, we optimize conditions to ensure high recovery rates (up to 98.8% for FePO₄ under optimized conditions) and product purity. Our findings demonstrate that the proposed method effectively transforms waste slag into valuable iron phosphate, significantly reducing raw material costs and contributing to sustainable battery recycling practices. The regenerated LiFePO₄ cathode exhibits excellent electrochemical performance, achieving a discharge capacity of 160.7 mAh g⁻¹ at 0.1 C, which meets market standard levels. This research provides a solid foundation for enhancing resource utilization and advancing circular economy principles in the battery industry. Full article

Efficient waste management is instrumental in both reducing waste generation and mitigating CO₂ emissions. The Zero-waste City Pilot (ZWCP) policy, a location-oriented waste governance initiative, aims to minimize waste production, enhance waste management efficiency, and improve resource utilization. Therefore, does the ZWCP policy achieve the dual environmental effect of pollution reduction and carbon mitigation? Based on panel data from 158 cities in China from 2011 to 2021, this paper employed a difference-in-differences (DID) model to empirically assess the impact of the ZWCP policy on solid waste and CO₂ emissions. The results indicate that: (1) The ZWCP policy effectively reduced both solid waste and CO₂ emissions, and the estimation results are robust as shown by robustness testing. (2) The policy achieved pollution reduction and carbon mitigation through two transmission mechanisms: stimulating green technological innovation and strengthening environmental regulation. (3) Heterogeneity analysis revealed that the policy’s effects on pollution reduction and carbon mitigation are more pronounced in central regions, non-resource-based cities, and large cities. (4) The ZWCP policy demonstrated no discernible enterprise exit effect, indicating its success in balancing environmental protection with economic growth, thereby providing a strong rationale for its extension to additional pilot regions. (5) The spatial spillover effect analysis revealed no significant spatial spillover of the ZWCP policy’s dual environmental effects. This may stem from the policy’s urban-centric implementation, uneven resource allocation and weak cross-regional collaboration mechanisms—factors that highlight the necessity for stronger cross-regional governance in waste management strategies. The study’s conclusions carry important policy implications for advancing China’s ecological civilization goals while provide valuable insights for other developing countries seeking to design effective zero-waste strategies. Full article

The valorization of agricultural residues, particularly corn stover, represents a sustainable approach for resource utilization and protein production in which high-performing microbial strains are essential. This study systematically evaluated fungal lignocellulolytic capabilities during corn stover solid-state fermentation and employed atmospheric and room-temperature plasma (ARTP) mutagenesis to enhance the degradative capacity of Trichoderma longibrachiatum. Comparative screening revealed that T. longibrachiatum exhibited superior comprehensive degradation of the major lignocellulosic components compared to other tested strains. ARTP mutagenesis yielded mutant strain TL-MU07, which displayed significantly enhanced enzymatic capabilities with improvements in FPase (22.1%), CMCase (10.1%), and xylanase (16.1%) activities, resulting in increased cellulose degradation (14.6%) and protein accumulation (14.7%). Proteomic analysis revealed 289 significantly differentially expressed proteins, with pathway enrichment demonstrating enhancement of glycosaminoglycan degradation, amino sugar metabolism, and membrane remodeling. Key mechanistic adaptations included downregulation of Zn(2)-C6 transcriptional repressors, upregulation of detoxification enzymes (ALDH-like proteins), and enhanced secretory pathway components. The ARTP-derived mutant strain TL-MU07 represents a valuable microbial resource for agricultural waste bioconversion, offering enhanced lignocellulolytic capabilities for industrial applications while elucidating specific proteomic changes associated with improved biomass degradation efficiency for sustainable protein production in the circular bioeconomy. Full article

In this work, a novel method for the disposal of ladle furnace slag (LFS) and soda residue (SR) was proposed. By applying geopolymer technology, LFS and SR were used as precursors to manufacture a geopolymer with sufficient fresh and mechanical properties that can be used in construction works, such as in non-structural components like lightweight partition walls. The effects of raw material ratios and Na₂O equivalents on the fresh properties, mechanical properties, microstructure and environmental impact of LFS-SR geopolymer (LSG) were analyzed by rheology, compressive strength, XRD, TG/DTG, SEM, and calculation of embodied carbon. The results showed that the compressive strength of LSGs increased when the SR content decreased or Na₂O equivalent increased, and the maximum compressive strength could reach 12.0 MPa at 28 d. The hydration products of LSG were mainly C-(A)-S-H gel, C₃AH₆, and AFt. Notably, the C-(A)-S-H gels formed a stable cross-linked structure, and the extremely fine granular C₃AH₆ further filled the pores. Furthermore, AFt was generated from the interaction between LFS and CaSO₄ rich in SR during the hydration process. The carbon calculation results indicated that the embodied carbon of LSGs was significantly lower than that of traditional cement, and the LSG containing 20% SR and 12% Na₂O equivalent had the highest sustainability. This study proposed strategies for mitigating the environmental hazards of alkaline solid waste and improving its resource utilization, thereby promoting sustainable development in the construction industry. Full article

Lignocellulosic waste biomass, a versatile natural resource derived from plants, has gained significant attention for its potential in the sustainable production of biobased chemicals. Furfural (FAL), xylo-oligosaccharides (XOSs), and reducing sugars are important platform chemicals, which can be obtained through the valorization of lignocellulosic solid biomass in a green and sustainable way. Waste yellow bamboo (YB) is one kind of abundant, inexpensive, and renewable lignocellulosic biomass resource. In order to improve the high-value utilization rate of raw YB, biochar-based solid acid catalyst (AT-Sn-YB) was utilized to assist the hydrothermal pretreatment for the valorization of YB in water. Under the optimal reaction conditions (200 °C, 60 min, and AT-Sn-YB dosage of 5.4 wt%), the FAL yield reached 60.8%, and 2.5 g/L of XOSs was obtained in the pretreatment system. It was observed that the surface structure of YB became rough and loose, exposing a significant number of pores. The accessibility increased from 101.8 mg/g to 352.6 mg/g after combined treatment. The surface area and hydrophobicity of lignin were 70.7 m²/g and 2.5 L/g, respectively, which were significantly lower than those of untreated YB (195.4 m²/g and 4.1 L/g, respectively). The YB solid residues obtained after treatment were subjected to enzymatic saccharification, achieving an enzymatic hydrolysis efficiency of 47.9%. Therefore, the hydrothermal pretreatment assisted by the AT-Sn-YB catalyst shows potential application value in FAL production and bamboo utilization, providing important references for other biomass materials. Full article

The issue of low resource utilization rate and high treatment cost in the disposal of construction waste and solid waste was a challenging problem. In order to seek a synergistic and efficient treatment method, based on the similarity of microstructural characteristics between clay, solid waste, and lithium slag particles, a dual-layer theory and model was used to conduct adaptive analysis at the electrochemical level, studying the solid–liquid–solid dual-layer theoretical model suitable for silicon–aluminum-phase materials. At the same time, the phenomenon of particle interface contact and the influence mechanism of ion adsorption on the surface of particles in the liquid phase were discussed, analyzing the ion selection mechanism for regulating the dual-layer of silicon–aluminum-phase materials and studying the method of clay-modified stabilization based on solid waste. Further laboratory tests and microscopic analyses were conducted to determine the engineering properties of the soil stabilized by the clay–solid waste synergistic stabilization and verified the effectiveness of the method. The research results showed that the trial soil stabilized by the theoretical model guidance was significantly stronger in unconfined compressive strength (1.44 MPa at 28 days) than the undisturbed clay (0.26 MPa at 28 days), and the scanning electron microscope (SEM) microscopic analysis results showed that the microscopic morphology of the modified stabilized soil specimen was tightly woven with a high-strength network-like structure. The research provided a theoretical basis and experimental reference for the synergistic treatment and resource utilization of waste soft soil and solid waste engineering problems. Full article

Glass and ceramics have a fundamental and crucial role in our lives due to their properties and aesthetic decoration. However, they create serious environmental problems, mainly due to their high occupation of landfills and harmful emissions. Both wastes could be utilized to reduce the natural resources’ adverse environmental effects and exhaustion. With increasing environmental concerns to reduce solid waste as much as possible, the concrete industry has adopted several methods to achieve this goal. Hence, this study examines the performance of self-compacted concrete (SCC) utilizing various percentages of recycled waste materials such as those deposited from glass and ceramic industries. The idea of utilizing recycled waste materials in concrete manufacturing has gained massive attention due to their impressive results in rheological and mechanical states. Recycled glass (RG) and ceramic waste powder (CWP) were utilized to replace fine aggregate and cement, respectively. Five mixes were designed, including the control mix, and the other four mixes had different dosages of RG and CWP as fine aggregate and cement replacement ranging between 5 and 25%. Mixes were tested for both rheological and mechanical properties to evaluate their compliance with SCC requirements as per codes and guidelines. The results revealed that 20% CWP or less as cement replacement and 10% or less of RG as a fine aggregate replacement would provide suitable rheological properties along with mechanical ones. Utilizing recycled glass and ceramic waste powder provides strength similar to the mix designed with natural resources, which helps us keep structures economically and environmentally friendly. Full article

Urban carbon emissions account for 75% of the total social emissions and are a key area for achieving the country’s “dual carbon” goals. This study takes the Sino-Singapore Tianjin Eco-City as a case, constructs a multi-dimensional carbon emission accounting model, integrates six systems, including buildings, transportation, water systems, solid waste, renewable energy, and carbon sinks, and proposes a comprehensive research method that takes into account both long-term prediction and a short-term dynamic analysis. The long-term emission trends under different scenarios are simulated through the KAYA model. It is found that under the enhanced low-carbon scenario, the Eco-City will reach its peak in 2043 (2.253 million tons of CO₂) and drop to 2.182 million tons of CO₂ in 2050. At the same time, after comparing models, such as random forest and support vector machine, the XGBoost algorithm is adopted for short-term prediction (R² = 0.984, MAE = 0.195). The results show that it is significantly superior to traditional methods and can effectively capture the dynamic changes in fields, such as buildings and transportation. Based on the prediction results, the study proposes six types of collaborative emission-reduction paths: improving building energy efficiency (annual emission reduction of 93800 tons), promoting green travel (58,900 tons), increasing the utilization rate of non-conventional water resources (3700 tons), reducing per capita solid waste generation (14,400 tons), expanding the application of renewable energy (288,200 tons), and increasing green space carbon sinks (135,000 tons). The total annual emission-reduction potential amounts to 594,000 tons. This study provides a valuable reference for developing carbon reduction strategies in urban areas. Full article

The valorization of agricultural and industrial solid by-products as secondary resources in the development of value-added materials can contribute to environmental health protection, particularly in the climate change era. Current advances in environmental legislation also encourage manufacturers to optimize waste management, upgrading and utilization towards resource conservation, energy efficiency and cost reduction in the context of a circular economy. In the present research, the elaboration of novel sustainable ceramics is investigated by sintering (at 800 °C for 2 or 6 h) of compacted mixtures composed of lignite fly ashes along with biomass ash (olive kernel ash) at different proportions. It appears that the chemical, mineralogical and morphological characteristics of these by-products promote their use as starting materials in ceramic engineering. Characterization and evaluation of the ceramics obtained via XRD and SEM-EDX analysis, as well as Vickers microhardness measurements, confirm the effectiveness of the consolidation process. In fact, the material derived from an 85% Class-C fly ash and 15% biomass ash compact, after 6 h sintering, exhibited greater results in terms of ceramic microstructure and microhardness (380 Hv), while a sintering time of 2 h was barely acceptable. The materials developed can be considered for use in various applications. Full article

This study successfully prepared MIL-101(Fe)@MoS₂ composite photocatalysts via hydrothermal methods to address the efficient removal of refractory organic dyes in dye wastewater. Characterization using X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) confirmed that molybdenum disulfide (MoS₂) was uniformly loaded onto the surface of MIL-101(Fe), forming a heterojunction that significantly enhanced light absorption capacity and charge separation efficiency. In a visible-light-driven photo-Fenton system, this material exhibited excellent degradation performance for Congo red (CR). At an initial CR concentration of 50 mg/L, a catalyst dosage of 0.2 g/L, 4 mL of added H₂O₂, and pH 7, CR was completely degraded within 30 min, with the total organic carbon (TOC) removal reaching 72.5%. The material maintained high degradation efficiency (>90%) across a pH range of 3–9, overcoming the traditional Fenton system’s dependency on acidic media. Radical-trapping experiments indicated that superoxide radicals (·O₂⁻) and photogenerated holes (·h⁺) were the primary active species responsible for degradation, revealing a synergistic catalytic mechanism at the heterojunction interface. Recyclability tests showed that the material retained 90.8% degradation efficiency after five cycles, and an X-ray photoelectron spectroscopy (XPS) analysis demonstrated the stable binding of Fe and Mo, preventing secondary pollution. This study provides a scientific basis for developing efficient, stable, and wide-pH adaptable photo-Fenton catalytic systems, contributing significantly to the advancement of green water treatment technologies. Full article

The high-value-added and resourceful reuse of solid waste is regarded as a promising technological approach within the construction industry, playing a vital role in advancing sustainable development and ecological civilization. In this study, VOSviewer and CiteSpace were utilized to systematically perform a bibliometric analysis of research related to the reutilization of solid waste in the construction sector, using data from the Web of Science Core Collection and Scopus databases. The analysis focused on publication volume over the last decade, global collaboration networks, thematic journals, keyword co-occurrence, and timeline clustering. The results reveal that: (1) The number of publications related to solid waste in construction has steadily increased over the last decade; (2) Significant research contributions have been observed from China. However, a cohesive core of contributing authors has yet to emerge, and broader, more equitable international collaboration remains necessary; (3) Research foundations span disciplines such as environmental science, materials science, physics, and chemistry, indicating a clear trend of interdisciplinary integration; (4) Current research primarily explores the performance and environmental impacts of concrete and waste-derived materials. Over time, topics have expanded from early explorations to include environmental assessments, waste management, and the circular economy, increasingly advanced technologies to investigate high-performance and diverse material applications. In the future, the energy efficiency and green sustainability of solid waste are expected to draw continued attention, with emerging technologies such as 3D printing and artificial intelligence likely to foster more interdisciplinary research in optimizing material performance. Full article

Anaerobic digestion (AD) of high-solid mono-chicken manure (CM) holds great promise for resource utilization. However, the effects of substrate overload (high-solid mixture inside the reactor) on AD performance at various temperatures are still unclear, moreover, the metabolic processes with and without inoculation are also seldom reported. In this study, three key impact factors of different temperatures (4 °C, 35 °C, 55 °C and 75 °C), total solids (TS) inside, and inoculation were conducted to comprehensively explore the process variation. EEM-FRI results revealed that high temps boost coenzyme F_420, while TS predominately driver the microbial production. High TS and temperature synthetically result in high free ammonia (FA) (>600 mg/L) associated with free volatile fatty acid (FVFA) (>450 mg/L), reducing CH₄ production but increasing VFAs accumulation (12 g/L at 55 °C). Notably, intestinal microbiota alone without inoculation even achieved 11 g/L of VFA. The cross-feeding symbiosis between fermentative bacteria (Caldicoprobacter, Bacteroidetes, Tepidimicrobium) and hydrogenotrophic Methanobacterium enhanced CH₄ production (68 mL/gVS at 35 °C). Moreover, high temperatures reduced microbial diversity but made heat-resistant hydrolytic bacteria dominant. This study precisely analyzes the effects of temperature and inoculation factors on the acidification efficiency of high-solid CM digestion, providing a crucial scientific basis for optimizing the resource utilization of CM waste. Full article

The substantial release of industrial carbon dioxide has been identified as a key factor in the development of various environmental issues. In addressing these concerns, the utilization of photocatalytic technology for carbon reduction has garnered significant attention. The disadvantage of CO₂ photoreduction is the problem of product yield and selectivity. It is known that MIL-125(Ti) with a high specific surface area (S_BET) possesses more active sites using Ti as a node. The calcination of MIL-125(Ti) in a reducing atmosphere has been shown to introduce oxygen vacancies (O_V), thereby enhancing the material’s surface and internal pores. This process has been demonstrated to result in a significant increase in the S_BET and an enhancement of the Ti³⁺/Ti⁴⁺ ratio. The increased Ti³⁺ centers have been found to improve the material’s reducing properties. The results demonstrate that the O_V-rich MIL-125-2H material exhibits the high-performance and highly selective photoreduction in CO₂. Full article

As an innovative inorganic cementitious material, geopolymer holds significant application potential in the field of road engineering. Based on the theoretical basis of industrial solid waste resource utilization and combined with geopolymerization technology, this study investigates the feasibility of applying lead–zinc-tailing-based geopolymer–stabilized aggregate (LZT-GSA) in road engineering through systematic mechanical property tests, durability assessment, and microstructural characterization. The study focuses on the influence of cementitious material admixture on the unconfined compressive strength, splitting tensile strength, compressive resilient modulus, drying shrinkage, and freeze–thaw cycle resistance of LZT-GSA. The experimental results demonstrated that LZT-GSA exhibited excellent properties in terms of mechanical performance and durability, which were remarkably better than those of conventional cement-stabilized aggregates (CSA). However, the incorporation of a small amount of lead–zinc tailing alone can weaken the mechanical properties of CSA. The drying shrinkage of LZT-GSA was slightly higher than that of CSA due to the difference in the intrinsic reaction mechanism between LZT-GSA and CSA. The effective cementing and wrapping effect of geopolymer gel on discrete aggregate dramatically improves the structural compactness of LZT-GSA. The leaching concentration of heavy metals in LZT-GSA is far below the requirements of environmental protection standards. These research results not only provide theoretical support for the resource utilization of lead–zinc tailings, but also lay a technical foundation for its practical application in road engineering. Full article