The copper-lead-zinc (CLZ) smelting industry is one of the major sources of atmospheric heavy metal (HM) pollution. This study developed a newly comprehensive atmospheric emission inventory for five priority-controlled HMs (Pb, Hg, Cr, Cd, and As) from the Chinese CLZ smelting industry during 2013-2023 to analyze spatiotemporal heterogeneity and assessed emission reduction potential driven by industrial development and environmental controls. Results indicated that national emissions of Pb, Hg, Cr, Cd, and As were 238.7 t, 24.7 t, 20.9 t, 21.3 t, and 41.3 t in 2023, respectively. Compared to 2013, emissions of Pb, Hg, Cd, and As decreased by 87.6%, 77.3%, 92.0%, and 92.1%, whereas Cr emissions increased slightly. Atmospheric emissions of HMs displayed significant spatial heterogeneity, predominantly concentrated in nine provinces (Anhui, Hunan, Jiangxi, Yunnan, Gansu, Inner Mongolia, Henan, Shandong, and Shaanxi), contributing 66.2%-76.8% to the national total emissions from 2013 to 2023. However, the contribution of key emission reduction provinces varied across periods: Hunan, Yunnan, and Gansu's emission reductions accounted for 39.7% of the national total during 2013-2018, with this proportion falling to 18.8% in 2018-2023. Additionally, emissions of the five HMs from lead smelting were predicted to decrease significantly across all scenarios by 2050, with reductions ranging from 16.5% to 84.4% compared with 2023. However, without strengthened pollution control measures, emissions of five HMs from copper and zinc smelting were projected to rebound, highlighting the risk without additional controls. Results could provide critical data for precise, region-specific governance of HMs in the industry.

As global warming intensifies, the low-carbon transformation of the iron and steel industry becomes crucial for achieving "dual carbon" goals. This study provided a systematic review of the carbon footprint calculation methods for the iron and steel industry based on life cycle assessment (LCA) principles and demonstrates the application of LCA in the source, process, end-use, as well as in cleaner production stages of steel production through specific cases. Results indicated that raw material acquisition contributed 3.9-8.8 % of carbon emissions (primarily from electricity consumption) throughout the entire life cycle of steel production. The blast furnace process dominated (75.0-82.1 % of carbon emissions) in basic oxygen furnace routes, while carbon emissions of electric arc furnace routes were primarily influenced by the electricity consumption intensity of the electric furnace. In the construction sector, carbon emission intensity of steel products was lower than that of wood when the recycling rate of scrap steel exceeded 70.0 %. While aluminum alloys used in car doors had lower life cycle carbon emissions than steel due to their lightweight properties. Cleaner production technologies, such as carbon dioxide capture and storage (CCS), sensible heat recovery from blast furnace, and slag reuse, demonstrated significant carbon emission reduction potential, providing critical support for the industry's green transition.

Chlorine-containing volatile organic compounds (CVOCs) pose significant risks of the environment and human health due to their high volatility, toxicity, and pollutant potential. Catalytic oxidation of Ce-based catalysts is widely regarded as one of the most effective methods to eliminate CVOCs since cerium oxide (CeOx) has highly efficient active sites of CVOCs catalysis and oxidation. However, challenges of CVOCs deep oxidation, chloride and carbon accumulation and catalytic oxidation mechanism limit the application and optimization of Ce-based catalysts. Based on recent development on the catalytic oxidation of CVOCs, this review systematically summarized the aspects of catalyst modification, reaction product selection, influence factors analysis and oxidation mechanism exploration. This study found the combination of Ce and other metals promoted the CVOCs deep oxidation. The modification of Co, Mn, Cu and noble metals elements improves the oxygen vacancies, reactive oxygen species and acidity/alkalinity property on the surface of Ce-based catalysts. Future research in the field of Ce-based catalysts development could focus on active component interaction modulation and the structural materials development. This paper provides an overview of the recent advances and challenges in CVOCs catalyst research, offering valuable insights for the future development of CVOCs catalytic technologies.

Quantification of carbon emissions from lead (Pb), zinc (Zn), and copper (Cu) smelting products has garnered increasing attention. However, consistent and comparable estimates across these products remain lacking. To address this gap, we conducted a systematic review and synthesis of life cycle assessment (LCA) studies published between 2000 and 2025. We categorised the approaches into three LCA types: enterprise-specific process-based, region-specific input-output, and hybrid. Thereafter, we built a dedicated carbon accounting framework for Pb, Zn, and Cu smelting products and the carbon emission profiles of the products. We found that the life cycle carbon emissions of Pb, Zn, and Cu smelting products are approximately 1586.9, 1881.1, and 16,587.9 kg CO2e/ t, respectively. Carbon emissions from the Cu smelting products were significantly higher than those from the Pb and Zn smelting products. Furthermore, the smelting stage is the predominant contributor to carbon emissions (51.9-66.1 %), and mainly influenced by smelting processes, energy utilisation efficiency, and raw material quality. These results support the sustainable development of the Pb, Zn, and Cu smelting industries and the formulation of carbon reduction policies.

Complex interdependent relationships exist among smelting quality, energy consumption, and pollutant emissions in basic oxygen furnace steelmaking, making traditional processes unable to achieve multi-objective optimization. This study developed a quality–energy–emission collaborative optimization framework for a 120-t top-bottom combined blowing converter, establishing a three-phase flow heat and mass transfer mathematical model for CO2-enhanced smelting. Using multi-physics CFD coupled with Pareto optimization algorithms, the influence mechanisms of top-blown CO2 ratio and bottom-blown flow rate on dephosphorization, denitrification, energy consumption, and particulate emissions were systematically investigated. CO2's endothermic reaction characteristics effectively regulated molten bath temperature and extended the favorable dephosphorization time window, while bottom-blown CO2 significantly improved denitrification by diluting nitrogen's partial pressure. The optimized configuration (top-blown CO2 ratio, 11.4%; bottom-blown flow rate, 71.88 m3/(h·t)) achieved significant collaborative optimization: steel's phosphorus content decreased by 12.79%, nitrogen content by 11.97%; oxygen savings were 3.70 m3/t steel, with energy recovery increased by 1.91 kgce/t; the particulate generation rate decreased by 2.96 g/s·t and net CO2 emissions decreased by 13.60%. Industrial validation confirmed the effectiveness of this approach, providing theoretical support and practical solutions for steel-industry green transformation.

At present, most reductions in heavy metals (HMs) emissions in the iron and steel industry (ISI) are attributable to synergistic decreases resulting from the implementation of dust removal, desulfurization, and denitrification facilities. However, the correlation between HMs and primary air pollutants (PAPs) emissions remains understudied. In this study, we systematically investigated the spatiotemporal evolutionary dynamics of HMs and PAPs emissions, as well as their synergistic effects, using an established long-time-series HMs and PAPs emission inventory based on a facility-level point source activity database. The results showed that HMs and PAPs emissions from the ISI in China were estimated at 1445.8 t and 1327.1 kt in 2023, respectively. Basic oxygen furnace and electric arc furnace processes were identified as the primary sources of HMs emissions. The Beijing–Tianjin–Hebei region and the Yangtze River Delta were identified as the main areas with high levels of HMs and PAPs emissions. Spring and summer were also identified as the primary seasons associated with elevated HMs and PAPs emissions. From 2013 to 2023, emission reductions of HMs ranged from 21.2% to 81.1%, while reductions of PAPs ranged from 37.0% to 87.0%. Among the PAPs, NOx exhibited the greatest synergistic reduction potential with HMs, whereas PM demonstrated the strongest synergistic effects with HMs. End-of-pipe treatment levels (65.9%–85.7%) and energy intensity (13.5%–33.4%) were identified as the primary drivers of synergistic emission reductions. These findings provide data support for the formulation of targeted policies aimed at achieving synergistic emission reductions of HMs and PAPs in the ISI.

Environmental Sustainable Development Goals (SDGs) interact with each other and with socio-economic SDGs in complex ways, involving both positive and negative influences of varying strength. Understanding these interactions is critical for identifying transformative actions that reduce trade-offs, enhance synergies, and accelerate progress toward environmental sustainability. However, the causal interactions remain underexplored, and priorities for coordinated governance actions are still unclear. This study assessed the weighted and directed interactions of 40 environmental targets within the SDG system based on expert elicitation. By using complex network analysis, we systematically analyzed the causal network, focusing on node-level importance, macro-level causal structure, edge vulnerability under multiple scenarios, and latent linkages. Our findings indicate that prioritizing target 13.1 (strengthen capacity to climate-related hazards) could be highly effective. Coordinated action between climate adaptation and marine ecosystem conservation can accelerate overall environmental progress. Furthermore, causal links along multiple shortest paths serve as critical bridges that sustain network resilience; targeted interventions on these links can amplify synergies and reduce trade-offs. Out of 2107 latent causal links predicted, six strongest positive interactions, primarily related to climate policy and forest management, stand out as potential focal points for environmental governance. This study offers new valuable insights for global environmental sustainability governance and supports progress toward achieving the 2030 Agenda.

The iron and steel industry, a predominant contributor to carbon emissions within China's industrial sector, occupies a pivotal role in the nation’s endeavor to achieve “carbon peaking and carbon neutrality”. This study employs a life cycle assessment (LCA) framework to develop a process-based carbon emission accounting model for iron and steel enterprises, comprehensively covering the three stages of raw material procurement, material transportation, and steel production processing (cradle-to-gate scope). The model is subsequently employed to calculate the carbon footprint of a sample Chinese iron and steel enterprise. The findings indicate that the enterprise’s CO2 emission intensity amounted to 2.32 tCO2/t crude steel in 2023. It is noteworthy that the steel production and processing stage emerges as the primary emission source, accounting for 67.15

Ultra-low emission coal-fired industrial boiler (CFIB) wastes, including bottom ash, fly ash, and flue gas desulphurisation (FGD) gypsum, are considered as hazardous substances because of their considerable hazardous trace elements (HTEs) contents. In this study, leaching tests were performed to investigate the leaching behavior of typical HTEs, and to analyse their potential environmental risks. Results showed that the leaching concentrations of Hg, As, Cr, Cd, Pb, Se, and Mn in waste under different leaching conditions did not exceed the standard values and were not classified as hazardous waste. HTEs in bottom ash, fly ash, and FGD gypsum exhibited varying leaching concentration levels at different acid-base conditions and were all characterised by unisexual leaching pattern, demonstrating a significant leaching of HTEs only under strongly acidic or alkaline pH conditions. In addition, higher liquid-to-solid (L/S) ratio conditions enhanced the leaching of HTEs from wastes, resulting in leaching rates of HTEs 67 to 363 % higher at L/S of 20 than at L/S of 5. However, the dependence of Cr, Cd, As, Se, and Mn leaching in ash on the L/S ratio was stronger than that in FGD gypsum due to their strongly acidic pH dependent. The effects of acid-base conditions on the environmental risks of HTEs in bottom ash, fly ash, and FGD gypsum were greater than the L/S ratio conditions. Strongly alkaline conditions were found to promote an increase in the integrated environmental risk values of bottom ash and fly ash by 113.9 %-134.1 % and 307.8 %-336.4 %, respectively, compared to the other conditions. Results could provide basic data for the development of policies for the environmentally safe management of HTE-containing wastes.

High energy consumption and concentrated carbon emissions in steel sintering have become key research priorities for industrial transformation. Existing studies suffer from singular technology assessments, linear simplifications of waste heat transmission, and a lack of quantitative evaluation of waste heat quality for carbon capture. This paper develops a collaborative carbon reduction scheme that integrates gradient energy-saving technologies across source-transport-sink stages. At the source, a CFD model based on gas-solid reactions dynamically integrates flue gas recirculation, dynamic fuel distribution (DFD), and recirculation flue gas control (RFGC), with particle swarm optimization (PSO) for sinter quality enhancement and fuel reduction. The transport stage establishes a pipeline network model simulating optimal temperature and flow attenuation. The sink stage employs MEA absorption-regeneration, with exergy analysis quantifying the impact of waste heat quality on irreversible carbon capture losses. Results show that the coupled process achieves 23.9% fuel reduction per unit sinter, an annual CO2 reduction of 2.11 & times; 105 t, stable 13.9 MW waste heat utilization, and exergy efficiency improvement from 35.1% to 43.1%. This study provides a verifiable pathway for integrated source-transport-sink transformation, contributing to carbon neutrality and energy efficiency enhancement in steel sintering.

This paper presents an innovative semi-surrogate model based on autoencoders, which corrects coarse mesh data to fine mesh data in computational fluid dynamics (CFD) using neural networks. In the offline training phase, coarse mesh data serves as input features, while fine mesh data is the target output. In the online phase, CFD calculations use coarse mesh data at a ratio of 1/5 (high-precision) or 1/10 (high-speed), invoking the saved network for correction to achieve either high-speed or high-precision modes. Testing results show that in high-speed mode, the acceleration ratio reaches 19.2 times, with an R2 accuracy coefficient exceeding 0.8; in high-precision mode, the acceleration ratio is 6 times, with an R2 coefficient exceeding 0.95. Additionally, to address the impact of hyperparameters on training outcomes, this study employs an Improved Dung Beetle Optimization (IDBO) algorithm to enhance accuracy in high-speed mode to above 0.85. Compared to traditional semi-surrogate methods, the proposed approach maintains good predictive accuracy under both interpolation and extrapolation conditions, providing new prospects for machine learning applications in fluid mechanics.

Coal-fired industrial boilers (CFIBs) are a priority for air pollution control and the leading sources of mercury (Hg) emissions. However, specific quantitative research on its impact on emission reduction remains limited. The spatial and temporal evolution of atmospheric Hg emissions from CFIBs in China was investigated in detail by establishing atmospheric Hg emission inventories at the technology level and facility level for the years 2000-2019 and 2020-2060. In addition, the impacts of various measures on atmospheric Hg emissions were quantitatively assessed. Results indicated that there was a 54 % rise in atmospheric Hg emissions between 2000 and 2012, followed by an 87 % decline between 2012 and 2020. During this period, the proportion of atmospheric Hg emissions increased by 10.3 % during the winter months. From 2020-2060, atmospheric Hg emissions were projected to decline annually, resulting in a total reduction ranging from 37.2 % to 58.8 %. The rate of decline was higher in general areas than in focus areas during this period. Our findings offer a more precise and detailed atmospheric Hg emission inventory from Chinese CFIBs, enabling the development of targeted control strategies and the management of atmospheric Hg emissions with regional differentiation.

Coal-fired industrial boilers (CFIBs) constitute a priority area of the China's Clean Air Plans. This study first detailed the effects of two Clean Air Plans implemented during 2012-2020 on the air pollutant emissions of Chinese CFIBs based on the establishment of an up-to-date emission inventory covering primary air pollutant species. Specifically, we analysed the spatiotemporal heterogeneity of air pollutant reductions, quantified the measure-specific emission reductions, and further investigated the synergistic effects for hazardous trace elements (HTEs) in the base years 2012, 2017 and 2020. Results showed that national emission reductions in PM, M2.5, SO2, NOx, and HTEs (sum of Hg, As, Cd, Cr, and Pb) were 3678.8 kt, 942.0 kt, 6672.5 kt, 1446.1 kt, and 5981.7 t from 2012 to 2020, respectively, with the largest reductions occurred in the period 2012-2017 (66.4-90.5 %). East China, Northeast China, and South-Central China were the most beneficial regions to achieve emission reductions of air pollutants, and their share of the contribution to emission reductions ranged from 80.1 % to 86.9 %. The measure of phase-out boilers resulted in the highest reductions in air pollutant emissions from 2012 to 2017 with the share of 58.7-66.3 % over the entire period, while its contribution was weakened by the upgrading of air pollution control devices during 2017-2020. The synergistic effect of NOx on HTEs was weaker than that of PM, PM2.5, and SO2 with the lowest cross-elasticity coefficient, and the degree of synergistic effects also exhibited stage-specific heterogeneity. The findings could provide new insights into the effectiveness of air pollution control policies in reducing pollutant emissions in major sectors.

Industrial boilers are an important anthropogenic source of CO2 emissions globally due to their considerable energy consumption. This study investigated the spatio-temporal heterogeneity and future reduction potential of CO2 emissions using the first established long time-series CO2 emission inventory of Chinese industrial boilers based on the updated localised emission factors and sub-fuel type activity level databases. Results showed that CO2 emissions from Chinese industrial boilers were estimated at 786.9 Mt in 2022, with coal-fired industrial boilers (CFIBs) contributing the most at 83.15 %, followed by gas-fired industrial boilers (11.71 %) and oil-fired industrial boilers (5.14 %). The hotspots with high CO2 emissions were primarily located in the northern regions with high heating demand and in the eastern coastal regions with a developed industrial economy. In addition, CO2 emissions exhibited an evolution of fluctuating increase followed by a decline from 1980 to 2022, with CO2 emissions peaking at 1637 Mt in 2012. Intense changes were observed in the structure of CO2 emissions of industrial boilers, with the contribution of CFIBs dropped yearly despite the historical dominance of CFIBs in CO2 emissions. CO2 emissions were predicted to maintain a downward trend under energy adjustment and environmental control scenarios. CFIBs would be the leading sector for achieving future CO2 emission reductions, with the potential expected to be 17-132 Mt, 141-302 Mt, and 223-588 Mt in 2030, 2050, and 2060, respectively. The results could provide the data basis for the scientific formulation of pollution reduction and carbon reduction policies for industrial boilers.

With the rapid development of adsorbents for removal of elemental mercury (Hg0) from coal combustion flue gas, the preparation of adsorbents with superior performance, lower cost and environmental friendliness remains an important challenge. An incipient wetness impregnation method followed by in-situ selenization was used to load copper selenide (CuSe) onto the surface of optimal magnetic biochar (OMBC). The results showed that CuSe significantly enhanced the Hg0 removal performance of the OMBC, and CuSe loading ratio of 10 % (10CuSe/OMBC) had the best Hg0 removal performance. 10CuSe/OMBC maintained its Hg0 removal efficiency above 95 % for 150 min at 30-150 degrees C, and it had a good resistance to SO2. The equilibrium adsorption capacity of 10CuSe/OMBC could reach up to 8.73 mg/g, which was close to the theoretical value 12.99 mg/g, and the adsorption rate was up to 20.33 mu g/(g min) Meanwhile,10CuSe/OMBC had strong magnetism that is not permanently magnetized, which could be separated from desulfurization gypsum and recycled many times. Characterization results demonstrated that Se 2 2- , Cu 2+ and O beta played essential roles in the oxidation of Hg0, and Se 2 2- and Se2-can immobilize Hg 2+ to HgSe.10CuSe/OMBC has important guiding significance for practical application because of its low cost, high performance and low mercury leaching characteristic to form HgSe. (c) 2025 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.

Carbon monoxide (CO) is an important air pollutant generated from the incomplete combustion of fossil fuels, particularly in industrial processes such as iron and steel smelting, power generation, and waste incineration, posing environmental challenges that demand effective removal strategies. Recent advances in noble metal catalysts for catalytic oxidation of CO, particularly Pt-, Pd-, and Rh-based systems, have been extensively studied. However, there is still a lack of systematic review on noble metal-based catalytic oxidation of CO, especially regarding the effects of different active components of the catalysts and the mechanism of sulfur resistance. Based on extensive research and literature findings, this study comprehensively concluded the advances in noble metal-based catalytic oxidation of CO. The effects of preparation methods, supports, and physicochemical properties on the catalytic performance of CO were explored. In addition, the mechanism of the catalytic oxidation of CO were further summarized. Furthermore, given the prevalence of SO2 in the flue gas, the mechanism of sulfur poisoning deactivation of catalysts and the anti-sulfur strategies were further reviewed. Exploration of new supporting materials, catalyst surface reconstruction, doping modification, and other catalyst design strategies demonstrate potential in improving sulfur resistance and catalytic efficiency. This study provides valuable insights into the design and optimization of noble metal-based catalysts for the catalytic oxidation of CO.

The capture of elemental mercury (Hg0) is the crucial step for synergetic control of mercury emission via dust removal equipment. Micropore structure, oxygen-containing groups and adding active elements are three key factors in the biochars activation for mercury capture. Previous studies usually focused on single modification factor. This study aims to evaluate and contrast the influence of the three key factors on the mercury capture of biochars. Physical activation (microwave and steam), H2O2 modification and NH4Cl impregnation were used to directionally develop pore structure, form new oxygen-containing groups and introduce halogen active sites. The testing results showed that physical activation causes distinct increase in the Vmicro ratio by 420 % yet just modest increase in the highest mercury removal efficiency (eta) of C6W by only 43.0 %. The 30 % H2O2 modification and 5 % NH4Cl impregnation distinctly increased eta by 82.6 % and 116.2 %, respectively. Moreover, synergetic activation of H2O2 modification with physical activation and that of NH4Cl impregnation with physical activation further increased eta by 159.5 % and 180.6 %, respectively. The pore structure development was not the key factor in mercury removal, yet it improved the chemical modification effectiveness. Physicochemical characterization methods, molecular adsorption kinetic models and mercury desorption energy calculation were used to analyze the mercury capture active sites and investigate the mercury adsorption mechanism. The H2O2 modification and NH4Cl impregnation formed chemisorption sites of C-O, C=O and C-Cl groups. The mercury desorption energy increased from 32.2-33.0 kJ center dot mol-1 of physisorption to 60.2-70.7 kJ center dot mol-1 of chemisorption. This paper provides guides for future preparation of highly effective mercury removal sorbents.

The eight Sustainable Development Goals (SDGs) related to resources (2, 6, 7), economy (8, 9), and environment (12, 13, 15), collectively known as REE, form the core of the human-nature system. Understanding their complex interactions is crucial for identifying transformative and effective governance actions. However, the causal mechanisms underlying the REE-related SDGs remain elusive. We used expert elicitation to assess weighted, directed interactions among 69 targets of these SDGs and applied network analysis and machine learning to identify their higher-order impacts, capacity to maintain network robustness, community structures, similarities, and systemic and structural roles. Additionally, we used causal emergence analysis and link prediction to examine potential characteristics of the causal network at macro and micro scales, respectively. The results indicate that prioritizing target 9.4 (sustainable & clean industries) can accelerate overall SDG progress while enhancing synergies and maintaining systemic resilience. In the macro-network, where causal emergence occurs, macronode E dominated by ecological targets plays the strongest facilitating role. In the micro-network, four predicted links with the highest weights indicate that strengthening scientific research and technological innovation is expected to be a potential focal point for positive impact. However, its possible negative effects warrant careful consideration. Additionally, significant trade-offs may arise between energy development and species conservation in the REE nexus that should be avoided. This study offers new insights into the causal mechanisms and priorities of the SDGs in REE, promoting global human-nature system coupling and accelerating the achievement of the 2030 Agenda.

With the acceleration of global industrialization, the issue of carbon dioxide (CO2) emissions has become increasingly severe, highlighting the urgent need to develop effective CO2 capture and utilization technologies. CO2 absorption-mineralization technology, as an emerging method, can convert CO2 into solid minerals, achieving both long-term storage and emission reduction goals. This paper systematically reviews the latest research progress in CO2 absorption-mineralization technology, with a particular focus on its application potential and sustainability in the steel industry. Additionally, it summarizes the research status and optimization strategies of various monoamine and mixed amine absorbents and explores the main process technologies, reaction mechanisms, and key parameters of industrial CO2 mineralization. Through multiscale modeling analysis, the study delves into the reaction mechanisms and influencing factors of the mineralization process, providing theoretical support for the industrial application of the technology. The research indicates that CO2 absorption-mineralization technology not only effectively reduces greenhouse gas emissions but also offers raw materials for industries such as construction, thus promoting sustainable resource development. Although this technology shows good application prospects, it still faces key challenges in economic viability and technical feasibility during practical implementation. This paper aims to clarify the current research hotspots and challenges, providing theoretical and practical support for future large-scale application.