Resource Recycling Research Articles

Enhanced ResNet-50 for garbage classification: Feature fusion and depth-separable convolutions.

As people's material living standards continue to improve, the types and quantities of household garbage they generate rapidly increase. Therefore, it is urgent to develop a reasonable and effective method for garbage classification. This is important for resource recycling and environmental improvement and contributes to the sustainable development of production and the economy. However, existing deep learning-based garbage image classification models generally suffer from low classification accuracy, insufficient robustness, and slow detection speed due to the large number of model parameters. To this end, a new garbage image classification model is proposed, with the ResNet-50 network as the core architecture. Specifically, first, a redundancy-weighted feature fusion module is proposed, enabling the model to fully leverage valuable feature information, thereby improving its performance. At the same time, the module filters out redundant information from multi-scale features, reducing the number of model parameters. Second, the standard 3×3 convolutions in ResNet-50 are replaced with depth-separable convolutions, significantly improving the model's computational efficiency while preserving the feature extraction capability of the original convolutional structure. Finally, to address the issue of class imbalance, a weighting factor is added to the Focal Loss, aiming to mitigate the negative impact of class imbalance on model performance and enhance the model's robustness. Experimental results on the TrashNet dataset show that the proposed model effectively reduces the number of parameters, improves detection speed, and achieves an accuracy of 94.13%, surpassing the vast majority of existing deep learning-based waste image classification models, demonstrating its solid practical value.

Commodity Zoning and Identification of Agricultural Practices Using an Agroecological Approach in Selur Village

Selur Village is an agrarian village where most residents rely on the agricultural sector as their primary source of livelihood. However, this sector faces challenges such as limited irrigation access, suboptimal land management, and the impacts of climate change. Agroecology offers an integrative solution combining ecological, social, and cultural aspects to enhance agricultural sustainability. This study aims to delineate superior commodity zoning through agroecological maps tailored to the biophysical potential of the area and to understand local farming practices based on agroecological principles. The research employs a mixed-method approach, with primary data obtained through interviews with 18 farmers, analyzed using Deductive Qualitative Analysis (DQA) to describe current farming practices, which were then interpreted about agroecological principles. Secondary data, including slope, elevation, air temperature, rainfall, and soil type, were spatially analyzed using QGIS to produce agroecological zone maps. Land suitability assessment was conducted using the matching method, aligning land characteristics with crop growth requirements. The results indicate that the majority of land in Selur village is suitable for perennial crops and forestry. Key commodities such as rice, maize, turmeric, and horticultural crops exhibit high compatibility with land conditions. The findings emphasize the application of agroecological principles, including crop diversification, soil conservation, and resource recycling, but highlight the need for further interventions. The study concludes by recommending strategies such as sustainable intensification, land rehabilitation, and enhanced market access to optimize agricultural productivity and resilience in Selur Village.

Crashworthy Performance of Sustainable Filled Structures Using Recycled Beverage Cans and Eco-Friendly Multi-Cell Fillers

The recycling of resources is an important measure to achieve circular economy and sustainable development. In this paper, a sustainable filled structure was proposed and realized by combining recycled empty beverage cans with eco-friendly multi-cell fillers. Quasi-static axial compressions were carried out to characterize the energy absorption performance and synergistic effect of the filled tubes. Experimental results showed that the crashworthiness of sustainable filled structures varied with both filling densities and materials. With the increase in filling density, the specific energy absorption of the filled tubes presented an upward trend. With the variation in filling materials, the filled tubes exhibited different crashworthiness performances. The PLA multi-cell filled tube could withstand larger external force and exhibited higher SEA values, with a maximum value of 9.64 J/g. The PLAS multi-cell filled tube showed excellent loading stability and lower ULC value, with a minimum value of 10%. These findings provided valuable insights for designing novel sustainable energy absorption structures.

Evaluating challenges and policy innovations for renewable energy development in a circular economy: A path to environmental resilience in Saudi Arabia.

Saudi Arabia is one of the largest greenhouse gas (GHG) emitters due to its heavy reliance on fossil fuels, has begun taking proactive steps to address climate change under Vision 2030. The initiative aims to reduce the country's GHG emissions. As part of this effort, the government is transitioning to renewable energy (RE) to decrease its dependency on oil and support sustainable environmental development. Additionally, the circular economy (CE) model, which promotes resource efficiency, waste reduction, and recycling, aligns with the core principles of RE, further enhancing the country's shift toward sustainability. Saudi Arabia has great potential for RE development but faces some challenges that call for the attention of major policy innovations. Therefore, this study used the fuzzy Decision Making Trial and Evaluation Laboratory (DEMATEL) method to assess the twelve key challenges. The fuzzy Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method is used to prioritize the seven policy actions for RE development within a CE framework in Saudi Arabia. The fuzzy DEMATEL findings indicate that the lack of regulatory support, high investment costs, and lack of skilled workforce are the most critical challenges. While the fuzzy TOPSIS shows that community engagement, diversifying funding sources, and educational partnerships are the top-ranked policy actions. These proposed policy actions are useful for maximizing RE potential, facilitating CE practices, and advancing environmental sustainability in Saudi Arabia. This study present that the policy innovations should be useful for governments and policymakers in adapting challenges and opportunities to achieve the aims of Saudi Vision (2030).

Selective gold extraction from e-waste leachate via sulfur-redox mechanisms using sulfhydryl-functionalized MOFs.

Urban mining of precious metals from electronic waste (e-waste) offers a dual advantage by addressing solid waste management challenges and supplying high-value metals for diverse applications. However, traditional extraction methods generally suffer from poor selectivity and limited capacity in complex acidic leachate. Herein, we present a sulfhydryl-functionalized zirconium-based metal-organic framework (Zr-MSA-AA) as a recyclable and highly selective adsorbent for efficient gold recovery. Specifically, the Zr-MSA-AA exhibits high recovery capacity (1021 mg g-1), remarkable pH-universal, and superb selectivity (Kd of 2.2 × 107 mL g-1) for gold ions across wide pH range and competitive conditions. Comprehensive mechanistic investigations highlight the pivotal role of sulfhydryl groups in selectively capturing gold ions. The redox-transformation of sulfhydryl and sulfonic acid groups mediated the reduction of Au(III) to Au(0) through the nucleation of chlorine-stabilized gold clusters. This unique mechanism, driven by the redox activity of designed sulfhydryl sites, not only mitigates interference from competing cations but also facilitates rapid adsorption kinetics (kf of 1.17 × 10-7 m s-1) for gold ions, surpassing the performance of previous adsorbents. Consequently, Zr-MSA-AA demonstrates exceptional practical applicability, achieving high-purity gold recovery (23.8 Karat) from real e-waste leachate through straightforward physical separation methods. This study introduces an alternative practical strategy for utilizing sulfur's redox activity in adsorbent design, advancing the sustainable recycling of non-renewable metal resources while contributing to environmental conservation.

Study on the preparation of calcium modified coal gangue and its adsorption performance of phosphate

The adsorption of phosphate in the collected water is crucial to alleviate the crisis of phosphorus resources, which is in line with the concept of green and sustainable development of resources. In this study, based on the calcium modification technology of pyrolysis combined with chemical modification, a new type of calcium modified coal gangue (CaMCG) was prepared by using coal gangue as raw material and calcium chloride as modifier for the removal of phosphate.The optimum preparation conditions of CaMCG were obtained by response surface test: mcalcium chloride:mcoal gangue=1, calcination temperature 735℃, calcination time 135 min. Batch adsorption experiments showed that when the phosphate concentration was 100 mg/L, the optimal CaMCG dosage was 0.5 g and the optimal reaction time was 48 h. At pH 3–7, the adsorption capacity of CaMCG for phosphate was always good. The order of the strength of coexisting anions affecting the adsorption of phosphate by CaMCG was: CO32− > SO42− > HCO3− > NO3− ≈ Cl−. Kinetic isotherm analysis showed that the adsorption of phosphate by CaMCG had both physical adsorption and chemical adsorption. The theoretical maximum adsorption capacity of CaMCG for phosphate was 17.85 mg/g. The adsorption process of CaMCG on phosphate conformed to the Langmuir model. The main mechanisms of CaMCG adsorbing phosphate are electrostatic interaction, surface precipitation, adsorption exchange and complexation. This study shows that CaMCG has great potential in adsorbing phosphate, which can provide technical reference for the efficient utilization of coal gangue and the treatment of phosphate wastewater.The phosphate adsorbed by CaMCG can be recycled and reused to achieve efficient and sustainable recycling of phosphorus resources.

Carbon Emissions from Food Consumption and Reduction Potential in Urban Residents: A Case Study of Provincial Capitals in the Middle and Lower Reaches of the Yellow River

Existing studies have established reliable methods for estimating carbon emissions from food consumption, yet there remains a lack of quantitative analysis on the decarbonization effects of energy transition and resource recycling. This study integrates lifecycle analysis and scenario analysis, based on data from 2006 to 2020, to conduct an empirical investigation of four provincial capital cities (Zhengzhou, Xi’an, Jinan, and Taiyuan) in the lower and middle reaches of the Yellow River, exploring the potential for reducing carbon emissions from food consumption and examining the driving effects of energy transition and resource recycling. The results indicate the following: (1) Per capita carbon emissions from food consumption decreased after 2016. (2) Incineration for power generation has a significantly higher carbon reduction effect than landfilling. The proportion of carbon emissions from food waste disposal decreased from 20% to around 6%, with the decarbonization potential of recycling transformation being 8.8%, 8.3%, 11.5%, and 14.4% in Zhengzhou, Xi’an, Jinan, and Taiyuan, respectively. Our findings suggest that promoting the widespread adoption of new-energy vehicles, increasing the share of renewable energy in power generation, optimizing food recycling technologies, and reducing food waste are crucial for achieving future reductions in carbon emissions from urban food consumption. The proposed methodology for assessing carbon emissions and reduction potential in food consumption can also be applied to other regions with varying geographical, economic, and policy contexts.

Shaping sustainable perceptions: The role of metaphors in Olympic news discourse.

The dissemination of sustainable development concepts in large international events like the Olympics has garnered great attention. As a major international sports event, the Beijing Winter Olympics served as an important platform for showcasing China's sustainable development philosophy through its official news coverage. In this context, metaphor, as a powerful cognitive tool, plays a crucial role in shaping public perception and facilitating the dissemination of values by mapping concrete source domains onto abstract target domains. This paper constructs a critical metaphor analysis framework for sustainable development, analyzing the mechanisms by which metaphors map the concepts of social, economic, and ecological sustainability, and their multifaceted roles in conveying policy proposals, ideologies, cultural values, and social group behaviors. The findings indicate that metaphors effectively facilitate public understanding of sustainability by concretizing abstract concepts. In the social dimension, metaphors emphasize fairness, cultural diversity, and social solidarity; in the economic dimension, they highlight resource recycling, technological innovation, and industrial upgrading; while in the ecological dimension, the focus is on environmental protection and the harmonious coexistence of humanity and nature. Metaphors play a crucial role in shaping public perceptions of policy, reflecting specific values and socio-cultural contexts, facilitating cultural communication and understanding, and enhancing public responsibility and participation awareness.

EOL‐NiMH Batteries: An Alternative for Critical Raw Materials. Chemical Characterization by WD‐XRF

ABSTRACTNickel‐metal hydride (NiMH) batteries hold not only the base metals but valuable rare earth elements (RREs) like La, Ce, Pr, and Nd. Given the importance of resource recycling and assured supply of the contained metals in such wastes, the present study has focused on the development of an XRF method able to fully characterize these residues. In this study, a robust method for the chemical characterization of the anode and cathode by wavelength‐dispersive x‐ray fluorescence spectrometry was developed. For that, NiMH batteries were manually disassembled to obtain the active materials used in the anode and cathode, where critical raw materials are used. The results showed that NiMH batteries' anode is valuable due to the high concentrations of La, Ce, Nd, and Pr, apart from Ni. Besides, the cathode is quite rich in Ni. The different composition of these two materials justifies the need for a recycling process that separates these fractions in order not to dilute the number of RREs and Ni that can be recovered from these batteries when they are disposed of.

CO₂-enhanced methane production by integration of bamboo biochar during anaerobic co-digestion

This study investigates the enhancement of methane production in anaerobic co-digestion (AcoD) through the introduction of exogenous CO₂ and the application of bamboo biochar. Exogenous CO₂ boosts biogas yield by providing an additional carbon source, which requires optimized solubility and pH buffering to ensure effective methanation. Biochar serves as an electron shuttle and pH stabilizer, facilitating CO2 solubility and syntrophic interactions that enhance microbial stability. When combined, biochar and CO₂ (R2) achieved a significant synergistic effect, increasing specific methane production (SMP) by 42.56% compared to the control (R0). Independent additions of biochar (R1) and CO₂ (R3) also improved SMP, with increases of 35.50% and 28.01%, respectively. This enhancement is likely due to the elevated activity of homoacetogenic bacteria and hydrogenotrophic methanogens, with increased acsB gene expression 2.4-fold with biochar+CO₂ and 1.5-fold with CO₂ alone compared to the control. Additionally, biochar facilitated syntrophic metabolism mediated by Cytochrome-C, promoting electron transfer. The study also demonstrated that biochar and CO2 could enhance enzyme activity, including acetyl-CoA synthase, mhpF, and mhpE. Such improvements bolster AcoD efficiency and promote resource recycling within the circular economy framework.

Dual benefits of resource recycling and pollution mitigation: Enhanced cadmium adsorption using modified biochar from traditional Chinese medicine straw

Dual benefits of resource recycling and pollution mitigation: Enhanced cadmium adsorption using modified biochar from traditional Chinese medicine straw

Green Innovation: The Key Role of Sustainable Design in Product Development

This study delves into the pivotal role of sustainable design in product development and how it fosters corporate innovation and competitiveness. Through literature review, case analysis, and mixed-methods research, the study reveals the positive impact of sustainable design on consumer behavior and the environment. Findings indicate that sustainable design not only propels the green transformation of product development processes but also stimulates innovation in material selection, production processes, and product lifecycle management within enterprises. The growing consumer demand for sustainable products further drives the market towards a more environmentally friendly direction. Additionally, the positive environmental impact of sustainable design is reflected in reduced resource consumption, decreased pollution emissions, and increased resource recycling rates. The research findings provide valuable insights and recommendations for policymakers, designers, and businesses to promote the widespread application of sustainable design globally.

Exploration of Practical Teaching of Resource Recycling Science and Engineering Major Based on the Training of Applied Talents

Resource recycling science and engineering is a new interdisciplinary subject. In order to meet the needs of the development of the circular economy, it is highly necessary to improve students’ innovative abilities and practical skills. This paper analyzes the problems existing in the practical teaching of this major and puts forward some approaches to the construction of practical teaching of resource-based major from the aspects of content system construction of practical teaching of resource recycling major, deep cooperation between schools and enterprises, construction of dual-teacher teams, and integration teaching of industry-university-research competition. It has effectively improved the training quality of applied talents in the resource recycling major.

Eggshell Waste to Wonder: A Novel Approach to Sustainable Cementitious Materials

Abstract: Eggshells, a widely available byproduct of food consumption, are generated in vast quantities globally, with significant waste accumulation in domestic and industrial settings. Despite their high calcium carbonate content, eggshells are often discarded, leading to environmental concerns such as landfill congestion and methane emissions. This study explores the potential of repurposing powdered eggshells as a partial replacement for cement in concrete production, addressing both waste management challenges and the sustainability of cement manufacturing. In this experimental investigation, cement was replaced by eggshell powder in varying proportions of 2.5%, 5%, 7.5%, and 10%. Concrete mixes were prepared, and the resulting properties, including mechanical strength and durability, were evaluated. The results showed that the mix with 10% eggshell powder replacement exhibited the best performance, demonstrating optimal mechanical strength and durability. This study underscores the feasibility of utilizing eggshells as a sustainable alternative material in concrete, contributing to circular economy practices. By reducing reliance on mined limestone and decreasing carbon emissions associated with traditional cement production, the use of eggshells offers an eco-friendly solution to both waste management and industrial sustainability. The findings support the growing recognition of eggshells as a recyclable resource in various industries, including construction, and highlight their potential to reduce waste accumulation while promoting sustainable development.

UV-Cured Robust and Transparent Double-Layer Membrane on Windows for Water Harvesting and Room Cooling.

The increasing demand for energy in cooling systems due to global warming presents a significant challenge. Conventional air-conditioning methods exacerbate climate change by contributing to heightened carbon emissions. Glass facades, renowned in modern architecture for their versatility and aesthetic appeal, inadvertently trap solar radiation, resulting in heat buildup and the greenhouse effect. To tackle these issues, we utilized roll-to-flat and light-curing technology to develop a hydrogel coating on a glass substrate with the assistance of ultraviolet (UV) adhesive. This water-contained hydrogel selectively absorbs ultraviolet and infrared light while allowing visible light transmission, thereby maintaining glass transparency. Leveraging the absorption of partial ultraviolet and infrared as active cooling and the liquid-to-gaseous phase change enthalpy of water as passive cooling, the hydrogel significantly reduces room temperatures by up to 8.1 °C under 0.75 sun irradiation, corresponding to a total room cooling power of about 192.6 W m-2. This study introduces a novel approach to transparent and energy-saving cooling in glass buildings, with the added potential for water resource recycling.

Surface Oxygen Vacancies on Copper-Doped Titanium Dioxide for Photocatalytic Nitrate-to-Ammonia Reduction.

Photocatalytic transformation of nitrate (NO3-) in wastewater into ammonia (NH3) is a challenge in the detoxification and recycling of limited nitrogen resources. In particular, previously reported photocatalysts cannot promote the reaction using water as an electron donor. Herein, we report that copper-doped titanium dioxide (Cu-TiO2) powders, prepared via the sol-gel method and subsequent calcination, promote NO3--to-NH3 reduction in water. The Cu2+ doping into TiO2 creates a large number of surface oxygen vacancies (OVsurf), which are stable even under aerated conditions. The Ti3+ and Cu2+ atoms adjacent to OVsurf behave as active sites for the NO3--to-NH3 reduction. Doping with an appropriate amount of Cu2+ and calcination at an appropriate temperature produce the catalysts with a large number of OVsurf, while maintaining a high conductivity, and exhibit a high photocatalytic activity.

Optimization Strategies for Electrocatalytic CO2 Reduction Based on Atomically Dispersed Copper: A Review

AbstractThe electroreduction reaction of CO2 (eCO2RR) is considered an effective pathway for clean fuel production, greenhouse gas reduction, and resource recycling. Atomically dispersed catalysts exhibit excellent catalytic activity due to the high dispersion of atoms, especially for atomically dispersed copper (AD Cu). Although copper‐based materials are considered major single component materials capable of producing multi‐carbon products, the reaction mechanism is usually not very clear. For AD Cu catalysts, the dynamic transformation of Cu species in the form of single atoms, (nano)clusters, and ions during the reaction process significantly has an effect on the performance of eCO2RR. The core issue that needs to be addressed is how to control and tune the aggregation of Cu atoms to make it most favorable for the desired product or reaction pathways. This review summarizes the optimization strategies for AD Cu in recent years from three main perspectives: interface engineering, electrode engineering, and external field coupling.

Research Progress on Oil-Water Separation Materials Based on Polyurethane Modification.

Numerous oil-water mixtures produced through industrial production processes and daily activities pollute the ecological environment and pose risks to human health. The development of materials with high oil-water mixture separation efficiency can promote the recycling of oil and water resources and effectively prevent environmental pollution caused by their direct discharge. Most of the current oil-water separation materials consist of foam, aerogel, and other porous materials. Among these materials, polyurethane exhibits good biodegradability, mechanical properties, large pore volume, low cost, wear resistance, and water resistance in oil-water mixture separation applications. However, pure polyurethane foam is characterized by low adsorption separation efficiency, insufficient recyclability, and high flammability. Therefore, modifying polyurethane to improve the oil-water mixture separation efficiency is vital. In this review, the methods and mechanisms of polyurethane modified materials used for oil-water mixture separation are reviewed, and their future research and application directions are prospected.

Strategic Resource Extraction and Recycling from Waste: A Pathway to Sustainable Resource Conservation

This study examines calcium extraction from Bottom Ash (BA) and the use of Solid Residue (SR) as a substitute for White Lump Clay (WLC) in brick production. Experimental analyses identified calcium and silicon as the main elements in BA, with 50% of calcium carbonate recovered through leaching. SR was a viable alternative to WLC in ceramic bricks, as SEM-EDS and FTIR analyses revealed changes in composition and microstructure. This approach promotes circular economy principles by recovering resources and reducing waste. Calcium extraction from BA can produce 29,000 tons of CaCO3 annually for industrial use, while substituting SR for WLC in brick production could replace 30% of clay, saving 1500 tons of clay and producing millions of bricks annually. Less than 50% of incinerated Municipal Solid Waste (MSW) would require landfilling. The process supports sustainable construction by conserving natural resources, reducing landfill waste, and lowering CO2 emissions. It offers annual cost savings of 2,639,250 USD and preserves 74,812.5 tons of resources through waste and clay reduction. By demonstrating a scalable model for waste valorization, this research aligns with global goals for sustainable development, resource efficiency, and ecological balance.

A novel stereoscopic mode of planting and breeding shed

A novel stereoscopic mode of planting and breeding shed has been designed. The shed body comprises of a steel frame structure inserted with 4 transverse beams along the length direction of the shed through the middle part of the shed body. The transverse beams are covered with a partition. The top of the shed body is covered with 300 and 80 solar panels, while the lower and upper sides are covered with the first and second transparent materials. The partition is provided with 200 and 40 breeding cages, where the 200 and 40 manure drains connected to the breeding cages (each manure drain connected to one breeding cage) are vertically arranged under the partition. The 2 manure collection pipes are connected to the manure drains at a slope of 60?. The transverse beams have 80 adjustable hammocks, which serve as space-saving hanging pots to grow plants. The lower side of the partition is provided with eighty spray heads through the pipes. The inner side of the shed body is provided with twenty heating devices. The novel planting and breeding shed can effectively utilize space, achieving the recycling of resources and waste, maximizing economic benefits and realizing the concept of low-carbon and green environmental protection.