Resource Recycling Research Articles

Novel process for high value utilization of high-alumina fly ash: valuable metals recovery and mesoporous silica in situ preparation.

Extraction of valuable metals besides silica from high-alumina fly ash is one of the most important high-value utilization pathways. However, it is difficult to realize high-efficiency extraction due to the stable structure e.g. of quartz and mullite. In this paper, mineral phase transformation for valuable metal recovery and mesoporous silica in situ preparation from fly ash by a selective acid leaching method was proposed. The mineral phase transformation, dissolution behavior of each metal, and pore structure of fly ash derived mesoporous silica were systematically investigated. The results show that the co-activation of fly ash by Na2CO3-K2CO3 formed the phases of kalsilite and (Na, K)AlSiO4. During the acid leaching process, Al, Li, and Ga could be leached with the efficiencies of 86.17%, 89%, and 80% in the FK system. In the FN system, the efficiencies of Al, Li, and Ga are 92.38%, 95%, and 83%, respectively. The crystal plane (002) was destroyed for kaliophilite while all the crystal planes were destroyed for nepheline. With the increase of HCl solution concentration, the porous silica exhibited the same change order of pore shape. The pore structure of as-prepared porous silica was type IV and the hysteresis loop was type H3, and the specific surface areas could be 565.54, 448.02, and 746.76 m2 g-1, respectively. Finally, the leaching liquors can be used to produce crystal aluminum chloride, lithium carbonate and gallium. This paper might provide technical support for full recycling of high-value resources from fly ash.

Exploring the effect of Brønsted acidity of MFI-type zeolites on catalytic cracking temperature of low density polyethylene

We verified the effects of the zeolite Brønsted acidity (acid strength, acid amount, location of acid sites, etc.) on the catalytic cracking temperature of low density polyethylene.

Green solvents in battery recycling: status and challenges

A green solvent hybrid system will bring about sustainable development in the battery industry by efficiently and environmentally friendly recycling of valuable resources contained in waste batteries.

Analysing the Circular Economies and Waste Management of European Countries via Decision Models

Today, waste management is a highly significant priority for the European Union. In 1975, the EU passed the first legislation on waste management, the Framework Directive on Waste, which laid the foundation for the EU's current waste management strategy. Since then, there have been several updates and revisions to waste management legislation to reduce waste and promote sustainable waste management. Today, developing a more circular economy is one of the main objectives of the EU's waste management policy. In order to do this, a circular model of resource reuse, recycling, and economic reintegration must replace a linear model of resource consumption and disposal. This can decrease the damaging effects of waste on the environment and increase resource efficiency. Efficient waste management cannot be maintained without implementing a circular economy thoroughly. The main goal of the analysis is to evaluate the performance of waste management in European Union nations from the viewpoint of the circular economy. We employ the MOORA and COBRA approaches to evaluate European Union countries’ waste management and circular economy performance. As per analysis findings, Germany and France perform better. Two sub-categories of the MOORA and COBRA method results significantly comply with each other. We may also conclude that the European Union countries that adopt circular economy-oriented policies perform better. This study aims to be a pioneer as it analyses both performance dimensions holistically in European Union countries using MCDM methods.

Research on Quality Grading Evaluation and Performance Prediction of Construction Waste Recycled Materials

The application of construction waste in road engineering is an effective means to improve the level of resource recycling. Due to the lack of specialized sorting equipment for different types of construction waste and the high cost of manual sorting, resource utilization enterprises mainly rely on mixed crushing and regeneration in production, while there is a lack of systematic research on the application technical indicators of recycled aggregates for brick concrete mixed construction waste. This article proposes a quality evaluation model for construction waste coarse aggregates based on the theory of matter element extension, providing new ideas for quantitative evaluation of the quality status of coarse aggregates, and also providing reference for the rational selection of recycled coarse aggregates and the determination of mechanical parameters of coarse aggregates in the construction process, which is conducive to the evaluation and analysis of the quality status of recycled coarse aggregates.

Using waste to treat waste: efficient alcoholysis of PET waste with a shrimp shell derived catalyst using the response surface method

The recycling of post-consumer PET waste is a significant area of scientific research, with great importance for resource recycling and environmental protection.

Resource Recycling Cultivation System in Enhanced-Closure Facilities

Resource Recycling Cultivation System in Enhanced-Closure Facilities

Pyrolysis-free synthesis of a high-loading single-atom Cu catalyst for efficient electrocatalytic CO2-to-CH4 conversion.

Electrocatalytic CO2-to-CH4 conversion provides a promising means of addressing current carbon resource recycling and intermittent energy storage. Cu-based single-atom catalysts have attracted extensive attention owing to their high intrinsic activity toward CH4 production; however, they suffer from uncontrollable metal loading and aggregation during the conventional pyrolysis process of carbon-based substrates. Herein, we developed a pyrolysis-free method to prepare a single-atom Cu catalyst anchored on a formamide polymer substrate with a high loading amount and well atomic dispersion through a mild polycondensation reaction. Owing to the isolation of copper active sites, efficient CO2-to-CH4 conversion is achieved over the single-atom Cu catalyst, along with the significant suppression of C-C coupling. As a result, the optimal single-atom catalyst with 5.87 wt% of Cu offers high CH4 faradaic efficiencies (FEs) of over 70% in a wide current density range from 100 to 600 mA cm-2 in the flow cell, together with a maximum CH4 partial current density of 415.8 mA cm-2. Moreover, the CH4 FE can reach 74.2% under optimized conditions in a membrane electrode assembly electrolyzer. This work provides new insights into the subtle design of highly efficient electrocatalyst for CO2 reduction.

Research Progress on Electrocatalysts for Electrocatalytic Carbon Dioxide Reduction

Electrochemical CO2 reduction reaction (CO2RR) is a vital strategy for achieving carbon neutrality by converting CO2 into high-energy-density, valuable chemical products, thereby facilitating carbon resource recycling and addressing environmental challenges. Herein, this paper emphasizes the role of CO2RR in diminishing the greenhouse effect through the transformation of CO2, with a particular focus on the latest advancements in Cu-based nanocatalysts, metal-organic framework (MOF)-based catalysts, and heteroatom-doped carbon materials, which are key innovations in achieving enhanced photoelectric conversion efficiency and steering CO2 conversion pathways. The paper also outlines the electrochemical principles of CO2RR, and the spectrum of potential reduction products, and navigates through the challenges of stability and production costs. The paper proposes strategies to surmount these hurdles, highlighting the critical role of industrial collaborations and breakthroughs in materials science. Future research should aim to pinpoint cost-effective, efficient catalysts for CO2RR, contributing significantly to mitigating the greenhouse effect and propelling forward sustainable energy solutions.

СТРАТЕГИЧЕСКИЕ ОРИЕНТИРЫ РАЗВИТИЯ ПРОМЫШЛЕННЫХ ПРЕДПРИЯТИЙ ДОНБАССА

The work highlights the guidelines for the development of the industrial complex of Donbass, through alternative economic and organizational tools of technological progress, allowing, in the context of the restoration of industrial enterprises of the Donetsk People’s Republic (hereinafter referred to as the DPR), the development of progressive forms of production organization (PFOP) and advanced management methods. An analysis of the existing practice of the considered areas of the organizational, economic and technical level of the industrial potential of Donbass made it possible to outline the concept of a comprehensive solution for the synthesis of production structures at the stages of reconstruction and technical re-equipment of production. The methodological basis is generally accepted in economic science methods of scientific analysis and synthesis, induction and deduction, generalization, comparison. The paper presents the results of analytical studies of an important component of the scientific and technical potential of industrial sectors of Donbass, which have significant untapped internal potential for activating and restoring its economic and technological structure to a higher neo-industrial competitive level. The main strategic guidelines for the development of industrial enterprises in Donbass are outlined, including: a) the creation of the Unified Fund for the Development of Science and Technology (EDFST); b) development of mini-factories on unused production areas of MMK im. CM. Kirov and Azovstal Iron and Steel Works; c) optimization of business processes of iron-containing components for resource recycling; d) development of progressive forms of production organization and innovative technologies.

Efficient and eco-friendly cadmium ion recycling: Ultrasonic enhancement of aluminum powder replacement for low-temperature industrial applications

Replacing cadmium ions in cadmium-containing solutions with aluminum powder is beneficial for cadmium resource recycling and environmental protection. However, the conventional aluminum powder replacement method requires harsh temperatures and prolonged conditions. In this study, the effect and mechanism of ultrasound on the replacement of cadmium with aluminum powder were investigated at low temperatures. Ultrasound has been proven to promote the etching of alumina films through the use of TEM and XPS, providing mechanistic support for the superiority of the new process. A degree of Cd replacement as high as 95.08 % is achieved at a low temperature (60 ℃) and in a short time (20 min) when using ultrasonicated aluminum powder replacement, which is 42.17 % higher than that of conventional aluminum powder. Compared with conventional aluminum powder replacement conditions with the same effect, the introduction of ultrasound can reduce the temperature by 30℃ and shorten the replacement time by 2/3, which has significant advantages in reaction efficiency and safety. The strengthening mechanism of ultrasound on the replacement effect of aluminum powder at low temperatures is revealed through detailed discussions on the corrosion of alumina films, agglomeration of aluminum powder, and adhesion of replacement products to the surface of aluminum powder, dissolved oxygen in the solution, and redissolution of cadmium. Therefore, a new approach for replacing aluminum powder in solutions with high Cd2+ concentrations at low temperatures is proposed in this work, which is expected to solve the existing harsh and dangerous problems of industrial aluminum powder replacement.

A Novel Colloid Electrophoresis Experiment with the Characteristics of Resource Recycling and Inquiry-Driven Experimental Design

A Novel Colloid Electrophoresis Experiment with the Characteristics of Resource Recycling and Inquiry-Driven Experimental Design

Engaging Creativity as an Alternative for Sustainable Inclusion and Integration in Schools: Visual Participatory Approach

Currently, the creativity approach is seen as one of the strategies used to support education through the teaching and learning process. In this regard, an art-based creative approach was used as a research design, which in recent years has been massively developed and has generated multiple data in research studies. Despite its collaborative feature and benefits, the creative approach is not usually employed in the teaching and learning process in schools, because this approach requires resources and time to accomplish the goals for the teaching and learning process in schools. This paper aims to evidence the use of the creative approach as an alternative for the sustainable inclusion and integration of learners in South African schools, as well as why it should be used as a supportive model in the educational context. To do this, the study presents a creative visual participatory approach which was done using recycled materials. The creative visual participatory approach and focus group interviews were employed with six teachers and six learners in the intermediate and senior phases in selected primary schools. Thematic data analysis enabled us to identify codes and themes that indicated the practical examples for inclusion and integration programs, events and sessions in schools. The data generation methods used met the standards of creativity expectations and extended the possibility of availability of recyclable resources and materials within the school environment. The findings reveal that creativity enhances critical thinking and problem-solving skills; thus, at present, both teachers and learners are benefiting from the use of this innovative strategy. The study also insists that it is crucial to employ the creativity approach for sustainable inclusion and integration of learners in South African school contexts.

A Review of Applications of Numerical Approaches for Unit Processes in Resource Recycling

A Review of Applications of Numerical Approaches for Unit Processes in Resource Recycling

Prospects for the effective use of fly ash in the technological processes of oil and gas production

The problem of efficient use of coal fly ash (CFA) is a global environmental problem that requires urgent attention and immediate action to address it. Research shows that huge amounts of CFA are generated every year, but only 25% of the waste is recycled. To overcome this alarming situation, there is a need to focus on increasing the use of coal ash in various industries. The promising uses of coal ash in construction, electronics, resource recycling, wastewater treatment, agriculture and other industries require further research. Of particular interest is the use of coal ash in industrial processes for the extraction of hydrocarbons. The physical, chemical and mineralogical properties of ash, such as its morphology, surface area, porosity and chemical composition, make it an ideal material for various field processes. Increasing the use of coal ash in various industries and its use in industrial processes for the extraction of hydrocarbon raw materials will significantly increase the level of utilization and reduce the negative impact on the environment. Keywords: coal fly ash; CFA; waste; hydrocarbon production; polymer gels; polymer flooding; enhanced oil recovery; nanoparticles; foam compositions; cementing compositions.

Hydration Characteristics of High Chloride Cement

High-chloride cement, enriched with calcium chloro aluminate (CCA), a compound of CaO-Al<sub>2</sub>O<sub>3</sub>-CaCl<sub>2</sub>, displays a higher Cl content than ordinatry portland cement. This specialized cement, incorporating limestone, clay, siliceous materials, and Cl-abundant cement kiln dust, is known for its superior early strength, making it an attractive option for resource recycling. However, the excessive Cl content can lead to reinforcement corrosion and a decrease in the durability of the hardened cement paste. Current research has primarily focused on its manufacturing characteristics, with studies on hydration reactions for practical application remaining limited. This study aims to explore the hydration reactions of high-chloride cement to determine its practicality. The experimental results reveal that high-chloride cement with abundant CCA significantly promotes the formation of ettringite, an Al-based hydrate, in the initial hydration stages. This process results in the binding of leached Cl ions with monosulfate, forming Friedel’s salt. Although the early formation of expansive hydrates might negatively affect long-term durability, mixing this cement with ordinary Portland cement in appropriate amounts can improve workability and enhance early strength and setting. Furthermore, the transformation of Cl ions into a crystallographically stable form like Friedel’s salt indicates a potential for safer usage, especially in reducing risks such as reinforcement corrosion.

Carbon tax and low-carbon credit: Which policy is more beneficial to the capital-constrained manufacturer's remanufacturing activities?

Remanufacturing has attracted much attention for its enormous potential in resource recycling and low-carbon emission reduction. To investigate the effects of different government intervention policies on remanufacturing and carbon emissions, two profit maximization models of the capital-constrained manufacturer under carbon tax and low-carbon credit policies are constructed respectively. Then, through theoretical and numerical analyses, some significant findings are drawn: (1) Both carbon tax and low-carbon credit policies can encourage capital-constrained manufacturers to produce more remanufactured products, but which intervention policy is more advantageous also depends on the carbon emission cost of new products or financing cost of the remanufactured products. (2) Although carbon tax policy can effectively control carbon emissions, it is always at the expense of both capital-constrained manufacturers and consumers; while low-carbon credit policy can help capital-constrained manufacturers achieve the goal of win-win economic and environmental benefits when the remanufacturing carbon savings advantages are more apparent. (3) From the perspective of consumer benefits, carbon tax is more advantageous when the consumer willingness to pay for remanufactured products is higher; otherwise, low-carbon credit policy should be implemented. (4) The higher the environmental damage coefficient is, the more it can highlight the advantages of the two intervention policies in social welfare enhancement, especially the carbon tax policy; and when the environmental damage coefficient is given, the stronger the consumers’ willingness to pay for remanufactured products is, the more it is conducive to reducing the negative effects caused by the carbon tax or low-carbon credit policy in social welfare enhancement, or increasing the corresponding positive effects. Based on above findings, some managerial insights and policy implications are provided to capital-constrained manufacturers and policy-makers.

Investigation Of the Biodegradable Plastic and The Application by Cornstarch and Kappa-Carrageenan

By comparing the manufacturing of conventional plastic with biodegradable plastic, a brief investigation of plastic and future developing trend was done. It is essential to investigate a biodegradable polymer which is produced with low cost and recyclable resources. An experiment was carried with cornstarch and kappa-carrageenan, which aim to produce a natural polymer can be biodegradable and has similar properties to conventional plastic. This experiment focuses on the mechanical properties and solubility of different amount ratio of the dry components to find out whether it has any functions that can be use in daily life. The results show the membrane with higher ratio carrageenan represents lower solubility, better mechanical properties and water resistance, but these properties become weaker in dry environment. The results provide a theoretical basis of the application of this polymer in medical region and food packaging.

Synthesis of X@DRHC (X=Co, Ni, Mn) catalyst from comprehensive utilization of waste rice husk and spent lithium-ion batteries for efficient peroxymonosulfate (PMS) activation

Highly efficient resource recycling and comprehensive utilization play a crucial role in achieving the goal of reducing resource wasting, environmental protection, and achieving goal of sustainable development. In this work, the two kinds waste resources of agricultural rice husk and metal ions (Co, Ni, and Mn) from spent lithium-ion batteries have been skillfully utilized to synthesize novel Fenton-like catalysts. Desiliconized rice husk carbon (DRHC) with rich pore structure and large specific surface area from rice husk has been prepared and used as scalable carrier, and dandelion-like nanoparticles cluster could be grown in situ on the surface of the carrier by using metal ions contained waste water. The designed catalysts (X@DRHC) as well as their preparation process were characterized in detail by SEM, TEM, BET, XRD and XPS, respectively. Meanwhile, their catalytic abilities were also studied by activating potassium peroxomonosulfate (PMS) to remove methylene blue (MB). The results indicate X@DRHC displays excellent degradation efficiency on MB with wide pH range and stable reusability, which is suitable for the degradation of various dyes. This work has realized the recycling and high-value utilization of waste resources from biomass and spent lithium-ion batteries, which not only creates an efficient way to dispose waste resources, but also shows high economic benefits in large-scale water treatment.

Ecological Circular Agriculture and Green Development

1) Identify the ecological and environmental problems facing agriculture; (2) Introduce the need and importance of developing organic farming and green development; (3) Model and technology of organic farming (recycling of waste resources; use of biodiversity; green substitution and reduction of chemical inputs, mitigation of greenhouse gases, etc.); (4) Regulation of policies and laws