Efficiency assessment of industrial solid waste generation and treatment processes with carry-over in China

Optimizing material circularity pathways in industrial waste streams: A decision-making model

The increasing pressures of environmental regulation and the introduction of new policy frameworks by various nations have accelerated the popularization of industrial solid waste management and recovery, underscoring the transition towards a circular economy. This paradigm shift emphasizes the importance of material recovery, reuse, and recycling of industrial waste to minimize environmental impact and enhance sustainability. Despite the availability of individual approaches for waste recovery, there exists a significant gap in the systematic selection of optimal recovery pathways that facilitate the reintegration of materials into the production cycle. Addressing this gap, our study introduces a novel optimization model designed to identify the most efficient material circularity routes that leverage both the technical and biological cycles of the circular economy framework. Utilizing the Genetic Algorithm optimization tool in MATLAB, our model prioritizes pathways that maximize material recovery and profit generation simultaneously. This dual-objective function serves as the cornerstone of our analysis, ensuring a balanced approach to environmental sustainability and economic viability. The model's efficacy was tested on pre-calculated quantities of fabric waste generated by the Biyagama Export Processing Zone, providing a practical case study for its application. Our findings reveal diverse scenarios under which the model can allocate varying weights to each objective, demonstrating its flexibility and utility as a decision-making tool for stakeholders in the waste management sector. The results indicate that the model is not only capable of optimizing waste circularity pathways for maximum material recovery and profit generation but also offers a customizable framework that can adapt to the specific priorities of different stakeholders. This research contributes to the existing body of knowledge by filling a critical gap in the selection of sustainable waste recovery pathways, offering a practical, optimized, and scalable solution that can significantly advance the goals of the circular economy in the industrial sector.•Decision-making model for stakeholders in the waste management sector.•Model selects the best material recovery pathways.•Textile industrial fabric waste stream used as a pilot to test the model's effectiveness.

Revealing the solid solution tendency of tungsten ions in phases of Ordinary Portland cement clinker: A study based on experiments and DFT calculations

The collaborative utilization of solid waste through cement kiln represents a highly effective approach in the current era for harnessing solid waste resources. In this paper, density functional theory simulations is used to predict the substitution tendency of tungsten (W) in Ordinary Portland cement (OPC) clinker. By employing experimental design, X-ray diffraction testing, and element distribution spectrum analysis, the doping preference of W ions in OPC clinker was comprehensively investigated. The findings demonstrate that a minor fraction of WO3 firstly infiltrates C4AF through the substitution of Fe atoms, whereas the majority of WO3 infiltrates C3S and C2S secondly by substituting Si atoms, with negligible infiltration observed in C3A finally. The substitution of Fe with W exhibits a lower formation energy compared to other ions, thereby indicating its preference for the formation of solid solutions in C4AF. This preference is primarily determined by the overlapping distribution of WO and FeO bond order-bond length and their similar electron contributions in spatial distribution. However, it should be noted that the newly formed WO bond has weaker strength than the FeO bond, which may explain the limited solubility of W in C4AF. The in-depth investigation of these fundamental issues is expected to offer an effective approach for enhancing solubility of W in OPC clinker through increasing content of C4AF and silicate minerals, thereby providing valuable guidance for synthesizing OPC clinker using W-bearing solid wastes.

Can industrial symbiosis policies be effective? Evidence from the nationwide industrial symbiosis system in China

Policies directly or indirectly influence the development of industrial symbiosis (IS). Quantitatively analyzing the effects of policies on IS at a national level is necessary, but current research has lagged. Focusing on the symbiotic system that includes the thermal power industry, cement industry, iron and steel industry, and social sector in China, this paper assesses the efficacy of policies on this nationwide IS system between 2015 and 2022. A policy influence framework is proposed, combining a cost-benefit analysis, agent-based model, and comparative analysis. Results show: (1) the symbiosis probability of the nationwide IS system experiences a fluctuating increase. The maximum increments of the symbiosis probability are 5%, and the resulting environmental benefits are equivalent to an emission reduction of 6.99 Mt from blast furnace slag, 20.97 Mt from iron mine tailing, 36.02 Mt from household waste, 25.01 Mt from steel slag, and 22.95 Mt from fly ash. However, the stimulation effects of policies vary across different subsystems. (2) Thermal power-chemical subsystems, thermal power-environmental protection subsystems, iron and steel-environmental protection subsystems, and social sector-cement subsystems need policy support in the future. (3) Approximately 50% of fields in this nationwide IS system is insensitive to current policies; policy approaches should shift from economic stimulation to symbiotic guidance. This paper fills the research gap by quantitatively studying the IS policy efficacy from a national level. The findings can contribute to the improvement of the Chinese IS policy system.

Symbiotic integration of waste disposal capability within a city cluster: The case of the Yangtze River Delta

With the ongoing urbanization in developing regions, integrating regional waste disposal capability is challenging due to unbalanced economic development and rising environmental issues. This research proposed a multi-dimensional symbiotic integration of waste disposal capability. Applying data from the Yangtze River Delta (YRD) in China, we first explore the waste flows and interactions between cities to identify the possibility of inter-municipal collaboration based on the augmented gravity model. We then employ social network analysis to categorize the cities in the collaborative network of waste disposal into subgroups by functionalities. Finally, we proposed the top-down framework of symbiotic networks for waste disposal. Our findings indicate that YRD cities can be classified into four types according to their waste density and disposal efficiency: High-High, Low-High, Low-Low, and High-Low. We also identify three types of inter-municipal collaborative relationships: between high-density and high-efficiency cities, between high-density cities, and between high-efficiency cities. The city subgroups can be categorized into "high-efficiency clusters," "high-density clusters," and "hub clusters," which pave the way for a shared or complementary urban symbiosis in the waste recycling industry. The division of roles among subgroups enables symbiotic activities within the city cluster. This paper extends the spatial scope of industrial symbiosis literature and has practical implications for transitioning to a circular economy in waste management of developing countries.

Efficiency Assessment of Hazardous Waste Disposal in EU Countries: A Three-Stage Super-Efficiency Data Envelopment Analysis Model

Hazardous waste pollutes the air, soil, and water and adversely affects human health if not disposed of safely. Analysis of the efficiency of hazardous waste disposal is essential to sustainable development. This paper uses the three-stage super-efficiency Data Envelopment Analysis model to measure the efficiency of 28 EU countries from 2004 to 2016. To ensure the reliability of the results, the article utilizes a one-way ANOVA statistical test to verify whether DEA results vary significantly across various EU countries. This article discusses "how inputs and outputs can be adjusted to eliminate inefficiencies" to suggest a targeted improvement. The third stage supper efficiency DEA results shows that the efficiency varies significantly across different EU countries. The main reasons for the low efficiency are high generated hazardous waste, management expenditure, greenhouse gas emissions, and inadequate waste disposal volume. Targeted proposals from three aspects are given for policymakers in EU countries: Build a resource recycling system to reduce hazardous waste. Establish a sound fee management system to reduce expenses. Optimization of disposal technology to improve incineration efficiency.

How does financial development alleviate pollutant emissions in China? A spatial regression analysis

Assessing the environmental effects of financial development has an important theoretical and practical reference for the government to achieve the goal of sustainable development. Financial development is affected dramatically by the real economy and typically shows nonlinear characteristics. This study aims to investigate the nonlinearity between financial development and pollutant emissions while considering the various stages of financial development among regions. Also, the spatial transmission mechanism between financial development and pollutant emissions is analyzed theoretically. Industrial sulfur dioxide ([Formula: see text]) and solid waste (SW) emissions are used to quantify pollutant emissions in China. The results show a positive spatial spillover effect on pollutant emissions across various regions. Moreover, a region's pollutant emissions can be influenced by the financial development of its surrounding regions, suggesting that financial development reduces [Formula: see text] emissions in a particular region, but it significantly increases [Formula: see text] emissions in surrounding regions, indicating a strong spillover effect. However, financial development significantly decreases SW emissions of a particular region but does not exert a significant impact on its surrounding regions, implying a weak spillover effect. Our results reveal that whereas the relationship of financial development with [Formula: see text] and SW emissions shows a significant U-shaped pattern, that of economic growth exhibit a significant inverted U-shaped pattern. The investigation can help in designing appropriate environmental policies for promoting financial development.

Analysis of OFDI Industry Linkage Network Based on Grey Incidence: Taking the Jiangsu Manufacturing Industry as an Example

Based on the outward direct investment data of each manufacturing industry segment in Jiangsu Province from 2000 to 2020, this paper establishes a correlation network by constructing a grey incidence model with the average value of absolute grey incidence as the threshold. We further analyze the relationship between each manufacturing industry segment in Jiangsu Province in the process of outward direct investment from two perspectives, namely, point and surface. The study shows that from the perspective of each node, the correlation coefficient between equipment manufacturing and other industries is significantly higher, i.e., the influence of equipment manufacturing on other industries is significantly greater. Chemical raw materials and chemical products manufacturing, general equipment manufacturing, special equipment manufacturing, and transportation equipment manufacturing are the important nodes in the network. From the perspective of the network as a whole, the Jiangsu manufacturing OFDI affiliation network is not concentrated. Still, it has small-world characteristics, which are conducive to disseminating information. In contrast, the close nature of the industry has more commonalities, leading to it being more easily divided into the same module in the network block model analysis.

Simulation of China’s Carbon Emission based on Influencing Factors

China is one of the world’s largest energy consumers and carbon emitters, and the situation of carbon emission reduction is serious. This paper forecasts the future trend of China’s carbon emissions by constructing a system dynamics model of China’s carbon emissions. The results show that China cannot fulfill its commitment to peak its carbon emissions in 2030 as scheduled. Secondly, the Logarithmic Mean Divisia Index model (LMDI) was used to analyze the influencing factors of China’s carbon emissions. The contribution rates of the five factors to China’s carbon emissions are as follows: economic development (226.30%), technological innovation (−105.92%), industrial structure (−26.55%), population scale (11.44%) and energy structure (−5.28%). Finally, this paper formulates five carbon emission reduction paths according to the size and direction of various factors that affect China’s carbon emissions. The paths of carbon emission reduction were simulated by using the system dynamics model of China’s carbon emissions. It is found that technological innovation is the key pathway for China to realize its commitment to carbon emission reduction. Slowing economic growth will delay the arrival time of peak carbon emissions and increase the intensity of carbon emissions. Optimizing the industrial structure, reducing the population scale and adjusting the energy structure can reduce the peak and carbon emissions in China, but the effect is small.

Efficiency Evaluation of Chinese Provincial Industrial System Based on Network DEA Method

The operation process of the Chinese provincial industrial system consists of four stages, namely the production (P) stage, wastewater treatment (WWT) stage, solid waste treatment (SWT) stage, and sulfur dioxide treatment (SDT) stage. Based on this structure, a four-stage data envelopment analysis (DEA) model is developed to evaluate the eco-efficiency, production efficiency, wastewater treatment efficiency, solid waste treatment efficiency, and sulfur dioxide treatment efficiency of provincial industrial systems in China, considering the undesirable output and variable returns to scale (VRS). Based on the objective data from 2011 to 2015, the following conclusions are drawn: Firstly, the eco-efficiency of the Chinese provincial industrial system has not been significantly improved during the study period, and the average eco-efficiency score is low, only 0.3805. Secondly, the reasons for the low eco-efficiency of the industrial system are different in the Eastern, Central, Western, and Northeastern regions. Thirdly, compared with the P stage, industrial WWT stage, and SWT stage, the efficiency of SDT stage is still relatively weak.

Prediction of China’s Industrial Solid Waste Generation Based on the PCA-NARBP Model

Industrial solid waste (ISW) accounts for the most significant proportion of solid waste in China. Improper treatment of ISW will cause significant environmental pollution. As the basis of decision-making and the management of solid waste resource utilization, the accurate prediction of industrial solid waste generation (ISWG) is crucial. Therefore, combined with China’s national conditions, this paper selects 14 influential factors in four aspects: society, economy, environment and technology, and then proposes a new prediction model called the principal component analysis nonlinear autoregressive back propagation (PCA-NARBP) neural network model. Compared with the back propagation (BP) neural network model and nonlinear autoregressive back propagation (NARBP) neural network model, the mean absolute percentage error (MAPE) of this model reaches 1.25%, which shows that it is more accurate, includes fewer errors and is more generalizable. An example is given to verify the effectiveness, feasibility and stability of the model. The forecast results show that the output of ISW in China will still show an upward trend in the next decade, and limit the total amount to about 4.6 billion tons. This can not only provide data support for decision-makers, but also put forward targeted suggestions on the current management situation in China.

Organic solid waste: Biorefinery approach as a sustainable strategy in circular bioeconomy

Waste generation is associated with numerous environmental consequences, making it a point of discussion in the environmental arena. Efforts have been made around the world to develop a systematic management approach coupled with a sustainable treatment technology to maximize resource utilization of organic solid waste. Biorefineries and bio-based products play a critical role in lowering total emissions and supporting energy systems. However, economic viability of biorefineries, on the other hand, is a stumbling hurdle to their commercialization. This communication provides a thorough study of the concept of biorefinery in waste management, as well as technological advancements in this field. In addition, the notion of techno-economic assessment, as well as challenges and future prospects have been covered. To find the most technologically and economically viable solution, further techno-economic study to the new context is required. Overall, this communication would assist decision-makers in identifying environmentally appropriate biorefinery solutions ahead of time.

A review on the industrial solid waste application in pelletizing additives: Composition, mechanism and process characteristics

Reducing the cost of pellet additives as a substitute for reducing bentonite binder is an important research direction of new pellet additives. There are some industrial solid wastes that have the similar physical and chemical properties to bentonite, and SiO₂ content of them may be much lower than bentonite, but also contains a lot of Fe₂O₃, Al₂O₃, MgO, B₂O₃ and other components beneficial to the quality of pellets, which have been paid more attention by many pellet workers. In this review, the effect mechanism of Fe₂O₃, Na₂O/K₂O, Al₂O₃, SiO₂, CaO, MgO and B₂O₃ in the industrial solid wastes on the fired strength and reduction expansion of pellets were systematically summarized. At the same time, the influences of five representative large scale modified industrial solid waste additives including iron tailings, bauxite tailings, fly ash, red mud and boron sludge on the properties of green pellets and finished pellets were described in detail. It can be seen that the applications of industrial solid waste in pellet additives can partially or completely replace bentonite binder, especially fly ash, red mud and boron sludge, which can not only improve the quality of pellets, but also decrease the cost, save energy and reduce pollution, with significant economic benefits.

How to Restrain Regulatory Capture and Promote Green Innovation in China. An Analysis Based on Evolutionary Game Theory

In response to severe environmental challenges, green innovation (GI) has been thoroughly considered by various governments. Although China has promulgated many environmental policies to promote environmental governance, regulatory capture and the lack of independent external supervisors lead to a challenging future. This study employs an evolutionary game method to explore how the policy burden and media affect decision-making between local governments and manufacturing enterprises. On this basis, the simulation method is used to examine critical factors that affect regulatory capture and GI. The results show that the policy burden is the main factor that causes regulatory capture. When the policy burden exceeds a certain threshold, it will cause regulatory capture and hinder GI. Moreover, media, as an external supervisor, can restrain regulatory capture and promote GI significantly. Specifically, when the capacity of media supervision is high enough, due to the positive role of the media, it will inhibit the negative effects of policy burdens. Finally, combined with the different development stages of China’s green industry, the corresponding policy recommendations are given. These results extend the research of regulatory capture and provide a reference for governments to promote environmental governance in practice.

Analysis of driving factors on China's industrial solid waste generation: Insights from critical supply chains

Industrial solid waste (ISW) poses a huge potential threat to human health and the environment. To prevent pollution at its source, it is necessary to analyze the socioeconomic drivers and identify the key supply chains that cause changes in ISW generation. In this study, based on monetary input-output tables (MIOTs) in China from 2011 to 2015, structural decomposition analysis (SDA) was used to study the influence of socioeconomic drivers on common industrial solid waste (CISW) and hazardous waste (HW) generation. Structural path decomposition (SPD) was used to further trace the effects of drivers at the supply chain level and obtain more meaningful results for policy formulation. Economic expansion was found to play the most crucial role in the increase in total ISW generation while the reduction of generation intensity effectively slowed the growth trend. From the final demand perspective, fixed capital formation contributed the most to ISW generation growth, accounting for 65.05% of the total final demand effect. Construction was the primary trigger. For CISW, the supply chain with the greatest overall influence was "metal ore mining industry → fixed capital formation" (including intermediate consumption of metal smelting, general and special machinery, and construction), reflecting how fixed capital formation indirectly affected the metal ore mining industry. The supply chain with the greatest influence on HW generation was "paper industry → exports." Based on the findings, corresponding policy adjustments are proposed.

Exploring the industrial solid wastes management system: Empirical analysis of forecasting and safeguard mechanisms

Industrial solid wastes (ISWs) not only destroys the ecological environment, but also seriously affects human health, which is one of the main obstacles to sustainable development. Consequently, Effective management of ISWs is essential to support efforts to achieve cleaner production and ecological upgrading of industrial structure. In this study, metabolic grey model (MGM (1,1)) is adopted to forecasting the ISWs generation and treatment in China. Meanwhile, we develop an ISWs management system involving its safeguard mechanisms. Forecasting results show that China's ISWs generated have been a slowly increasing trend from 2018 to 2025, which will be controlled between 389819 million tons and 488002 million tons, and the utilization, disposal and storage of ISWs have a significant upward trend. However, the ratio of ISWs utilized will eventually remain at around 50% in the future. According to the prediction results, the application of this ISWs management system can increase the efficiency of waste recycling and reuse, and make ISWs become renewable resources. Research results also illustrate that the safeguard mechanisms, including government policy tools, collaborative agents of the industry-university, green technology innovation, and circulation of green products, have ensured a highly efficient recycling and beneficial waste management to create more added values for the ISWs materials.

The Unified Efficiency Evaluation of China's Industrial Waste Gas Considering Pollution Prevention and End-Of-Pipe Treatment

With the deepening of industrialization and urbanization in China, air pollution has become the most serious environmental issue due to huge energy consumption, which threatens the health of residents and the sustainable development of the country. Increasing attention has been paid to the efficiency evaluation of industrial system due to its fast development and severe air pollution emissions, but the efficiency evaluation on China’s industrial waste gas still has scope for improvement. This paper proposes a global non-radial Network Data Envelopment Analysis (NDEA) model from the perspective of pollution prevention (PP) and end-of-pipe treatment (ET), to explore the potential reduction of generation and emission of air pollutants in China’s industrial system. Given the differences of different air pollution treatment capacities, the ET stage is further subdivided into three parallel sub-stages, corresponding to SO₂, NO_X, and soot and dust (SD), respectively. Then, grey relation analysis (GRA) is adopted to figure out the key factor affecting the unified efficiency. The main findings are summarized as follows: firstly, the unified efficiency of China’s industrial waste gas underperformed nationwide, and most provinces had the potential to reduce the generation and emission of industrial waste gas. Secondly, the PP efficiency outperformed the ET efficiency in many provinces and the efficiency gap between two stages increasingly narrowed except in 2014. Thirdly, the unified efficiency in the eastern area performed well, while the area disparities increased significantly after 2012. Fourthly, significant differences were found in three ET efficiencies and the ET efficiency of NO_X was higher than that of SO₂ and SD in the sample period. Finally, the results of GRA indicated that different air pollutants had distinct influence on the improvement of the unified efficiency in three areas. To promote the unified efficiency of industrial waste gas, some pertinent policy suggestions are put forward from the perspectives of sub-stages, air pollutants and areas.