Heterogeneous evolution and driving forces of multiple hazardous air pollutants and GHGs emissions from China's primary aluminum industry.

The booming of China's primary aluminum industry (PAI) brought substantial emissions of hazardous air pollutants (HAPs) and greenhouse gases (GHGs). By using life cycle assessment and bottom-up method, a comprehensive emission inventory for multiple typical HAPs and GHGs from China's PAI during 1990-2021 was developed and explored for the first time. Our results show that spatial-temporal emissions trends of HAPs and GHGs from PAI in China diverse significantly. The conventional atmospheric pollutants (including SO2, NOx and particulate matter (PM)), fluoride and per fluorinated compound (PFCs) had been effectively suppressed since 2007 due to the implementation of various environmental policies; while, emissions of CO, VOCs, CH4, heavy metals and CO2 had increased at different rates unexpectedly. From the spatial distribution perspective, Henan, Shanxi, Guizhou, Guangxi and Shandong dominated the emissions of PAI in China, but with consumption expansion and environmental constrains, PAI plants start to expand to northwest and southwest areas where are richer in sufficient and cheaper power resources, thus bring significant emission increasing there, particular for conventional atmospheric pollutants in northwest and CO and VOCs in southwest China. By underlying driving forces of PAI emissions, results show that end-of-pipe control measures at various stages have played different roles to reduce emissions of the concerned species at each period, but its reduction effect diminished gradually. Future reduction should seek underlying changes in production technology and energy system. Under constrains of environmental regulation and resource endowment, promoting circular economic development for PAI would be a key strategy to reduce HAPs and GHGs emissions simultaneously in PAI.

Material flow analysis and statistical entropy evaluation of plastic packaging for express delivery in China.

Encouraging the recycling of plastic packaging materials in express delivery is a necessary step toward environmentally friendly industrial development. In this study, we present a framework for analyzing the flow of materials in express plastic packaging, from production and manufacturing to consumption and recycling. In examining the use of recycled materials in post-consumer express plastic packaging and the destination of consumer packaging waste in 2020 and 2021, we found that 44.4% (1613.6 Gg) of the studied express plastic packaging was incinerated. Additionally, approximately 1296.6 Gg of express plastic packaging flowed into rural areas. Our calculations showed that the ΔRSE in 2020 was 15.1%, and on the condition that 25% separated collection with 80% recycling, ΔRSE would be - 0.5%. Results verified that separated collection is an important step in the recycling strategy for packaging materials. Survey data from universities in Beijing indicate that currently, 26% of college students are participating in the separate collection of packaging.

Analysis of the coupled flows of aluminum and copper in household air conditioning system.

The global "copper-poor and aluminum-rich" situation has made the possibility of "copper saving with aluminum" an important topic. This study established a framework for analyzing multiple substances' coupled flows at the product level based on material flow analysis (MFA), and took the household air conditioning system of the Chinese mainland in 2020 as an example to characterize the coupled flows of aluminum and copper. The results showed that the system consumed 0.69 million tons of aluminum and 2.10 million tons of copper, and discharged 0.17 million tons of aluminum and 0.43 million tons of copper to the environment cumulatively to achieve 13.2 million terajoules of final heat exchanged and serve 1.24 billion square meters during lifetime in mainland China alone, secondary aluminum and copper accounted for only 22.61% and 24.83% of the total consumption, and the in-use stocks increased by 0.19 million tons of aluminum and 0.70 million tons of copper. The external dependency of copper ore was 92.83%, which was significantly higher than the 44.29% of bauxite. The comprehensive utilization efficiency of copper reached 77.88%, which was slightly higher than the 70.80% of aluminum. The conclusion indicates that under the premise of meeting use requirements, promoting "replacing copper with aluminum" can improve the stability and safety of China's material supply chain, but there is a need to further boost the production efficiency of aluminum in primary production.

Analysis of iron composite flow in China.

Iron is an important metal material that is crucial to social and national economic development. In order to understand iron's material flow, energy flow, and value flow in China, a composite flow framework is here established. Based on this framework, the concept of price is introduced, and China is taken as an example to study the composite flow of iron in 2018. The results showed the following. First, as iron moved down the industrial chain, its material flow decreased gradually, while the price continued to rise. Second, the annual loss of raw materials from iron processing was 150-200 million tons, and scrap iron had great potential for secondary utilization. Third, China had a trade deficit in terms of importing raw materials and exporting products, but it also had a trade surplus in trade volume. Finally, China imported iron-containing goods at high prices but exported iron-containing goods at low prices. This was due to the lack of high-end science and technology, which made China less competitive in the international market.

Comparative analysis of internal and external characteristics of lead-acid battery and lithium-ion battery systems based on composite flow analysis.

Due to human's diversified requirements and the constraints of external environmental factors, lead-acid batteries and lithium-ion batteries coexist and compete with each other now. However, the difference of internal and external characteristics between the two battery systems is unknown. Based on the analysis of the internal flows and its impact on the external environment, this research established a framework for the relationship between the battery system and the external systems. The internal and external evaluation index system was developed. The external influence results of the two systems in China mainland at 2016 show that when the amount of social service provided by lead-acid battery system (LABS) was 1.6 times more than that of lithium-ion battery system (LIBS), the consumed lead ore was 52 times more than the lithium ore; the total energy consumption of the systems was 23.12 million tce, and that of the LABS accounted for about 63%; waste lead emissions was 2.7 million tons, and the waste lithium emissions was 40,900 tons lithium carbonate equivalent (LCE); the total economic outcomes were 220.23 billion yuan, and the proportion of that in LABS was about 44.4%. The recycle rates of LABS and LIBS were 0.368 and 0, respectively; the energy density of the LIB was 4.4 times of that in LAB; the "price" of the lithium in lithium ore and LIB were about 12 times and 3 times of that in LAB. The management suggestions on sustainable development were put forward from the aspects of waste recycling, product structure in the application field and product performance. What's more, future plan was discussed for the sustainable development.

Historical evolution of lead-acid battery system and its relationship with external environment based on the composite flow.

The quantitative demand for composite flow of lead-acid battery (LAB) system varies with the requirement from human and affects the external environment. A framework with four stages [production of primary lead (PPL), fabrication and manufacturing (F&M), use and waste management and recycling (WMR)] and the external dynamic evaluating system was developed. The historical evolution characteristics of the system in the Chinese mainland from 1990 to 2016 was investigated. For material aspect, the consumption of secondary lead increased faster. All lead ore was consumed in PPL and reduced by the average rate 1.2%. The total lead emissions declined before they increased, that in F&M reduced the most with the average rate 29%; the share of scrap lead in waste LAB was vital, 63%-75%. For energy aspect, the energy consumption in WMR grew faster. And the external performance of energy flow grew, that in PPL reduced the fastest with the average rate 31%, and the share of that in use was approximately 80%. For value aspect, the value of lead in LABs increased faster. The influence from the value flow grew negatively. The index of WMR increased the positively and fastest by average rate 85%, and its proportion of use was largest, about 313%. The evolution of the key internal factors was analyzed, which have a great influence on the system. The overall change of large recycling rate, intermediate recycling rate and lead emissions rate of WMR grew. The lead emissions rates of F&M and PPL increased before decreasing. The reasons influencing the variation, such as policies and technologies, were analyzed.

Quantitative analysis of the material, energy and value flows of a lead-acid battery system and its external performance.

The comprehensive optimization of lead-acid battery system (LABS) can promote the relationship between the development of human-socio-economic system and environment. Based on the lead anthropogenic cycle, LABS is divided into four stages: production of primary lead (PPL), fabrication and manufacture (F&M), use and waste management and recycling (WM&R). According to the relationship between LABS and external environment, a framework is developed for the coupling of composite flow (material flow, energy flow and value flow). The quantitative relations between external performance indicators (lead ore consumption, scrap lead emissions, energy consumption and increase in value) and the internal factors are established, and key factors that affect external performance and their impact level are identified. The results of Chinese LABS in 2014 indicate that the external performance of the material flow reduced as the decrease of the emission rates of PPL (γ1), F&M (γ2) and WM&R (γ4) and the increase of the large recycling rate (ατ) and production ratio. The impact level of the former three was 1.5-2.2 times higher than those of the latter two. γ2, γ4 and ατ had the higher impact level on energy consumption in descending order. The impact level of the emission rates was 2.0-3.0 times higher than that of the recycling rate. γ4, ατ, γ1, γ2, in descending order, were the four higher factors that affected the increase in value, and the impact levels of the farmer two were 1.5-2.0 times higher than those of the latter two. Moreover, γ4 and γ2 were the factors that influenced the whole external environment greater. The decreasing order of influence degree of the above factors on the external performance indicators was increase in value, energy consumption and the external performance indicators of material flow. The impact from coupling coefficients between energy, value and material on external performance is less than the above factors.

Anthropogenic antimony flow analysis and evaluation in China.

China is facing a shortage of antimony (Sb) resources, and Sb emissions are worsening. In exploring solutions to these issues, this paper attempts to apply substance flow analysis (SFA) to track Sb flow among the lithosphere, anthroposphere, and biosphere in China. The results are as follows: (1) China's Sb ore faces the risk of depletion. Although China has the largest Sb reserves in the world, the import of Sb concentrate accounted for a large proportion of the total material input during the production stage, which has increased from 9.78% in 2006 to 30.22% in 2016. Moreover, since 2013, the net export rate of Sb products during the manufacture and fabrication (M&F) stage has been growing, reaching 21.32% in 2016. (2) The Sb industry is highly dependent on ores. Moreover, the resource efficiency and cycling ratio of Sb are quite low. (3) Sb emissions cannot be ignored in industrial processes, particularly Sb emissions from the M&F and usage stages. Sb emissions discharged into the biosphere reached 1915.58 Gg in the period from 2006 to 2016.

Quantitative analysis of the coupling coefficients between energy flow, value flow, and material flow in a Chinese lead-acid battery system.

To reveal the historic characteristics of the material flow, energy flow and value flow in a lead-acid battery (LAB) system, a framework for the coupling relationship among the three flows was established based on material flow analysis and the characteristics of the energy and value flows. The coupling coefficients between energy and material (CCEM) and value and material (CCVM) were also defined. The investigation used by China as a case to study changes in stages and the historic evolution. The results show that the CCEM for lead in LABs was highest in the usage stage, approximately 5-16 times greater than in the other stages. The CCEM for production was almost twice as high for primary lead as for secondary lead, and the CCEM was lowest for the fabrication and product manufacture stage. The CCVM for lead in LABs was 2.5-6 times higher than for other types of lead. The CCVM was lower for scrap lead than for lead ore, and the CCVM was approximately 1.7 times higher for refined lead than for scrap and refined lead. For lead trade, CCVM was correlated with domestic and overseas markets. From 1990 to 2014, the CCEM for each stage was in decline, whereas the opposite was the case for CCVM. The influencing factors were analyzed in terms of resources, the environment, and markets. Increasing the circulation rate of scrap lead is an effective way to rapidly save resources, reduce lead pollution, and promote a circular economy. The limitations and potential value of the study are also highlighted, and future research is outlined.

Quantitative analysis of the spatio-temporal evolution of the anthropogenic transfer of lead in China.

The redistribution of lead to meet human needs reflects the relationship between humans and land, and the redistribution process will influence the future evolution of the land surface. An analysis of the spatial transfer of lead was undertaken to determine the regional distribution of lead in each phase of its life cycle during 1990-2014 using the administrative unit of each province in Mainland China as the spatial unit. A quantitative analysis of the spatio-temporal evolution of the anthropogenic transfer of lead in China was conducted through a comparison of the differences in the spatio-temporal distribution of lead at different stages of its life cycle. The results showed that during 1990 to 2014, the mining of lead ore was gradually transferred from southern China to the northwest inland area and northern China, and lead within products was finally transferred to the eastern coastal area of China to complete its life cycle. The distribution of natural and social resources, supply and demand of markets, and foreign trade affect the lead anthropogenic transfer.

Source analysis of global anthropogenic lead emissions: their quantities and species.

Lead emissions originate primarily from the anthropogenic lead cycle, and research into their characteristics, such as species type, provides essential information for pollution control. A dynamic model for global lead emissions has been established, and their emissions and temporal accumulations were estimated in this study based on the evolution of the lead cycle over 70 years. An inventory of the emissions species was obtained after identifying their physiochemical transformations. The 2010 emissions were 3.56 Mt, with 65 % coming from waste management and recycling. The main species were PbSO4 (42.5 %), PbO2 (16.2 %), and PbS (8.3 %). Between 1930 and 2010, the total lead emissions were 173.8 Mt, mainly from waste management and recycling (48 %), production (26 %), and use (20 %). The main species were PbSO4, PbO, Pb, and PbS, and together, they accounted for 61.2 % of the total emissions. Over time, species, such as tetraethyl lead and Pb, declined, but PbO2 and PbSO4 increased.

[Reasons for the changes in anthropogenic lead flows of China].

In recent years, accompanied by a series of comprehensive improvement actions on lead pollution, anthropogenic lead flows of China have somewhat changed; by exploring the reasons, some references can be provided for further improvement in resource utilization and environment quality. In this paper, based on the framework of lead flow analysis, the causes of changes in lead flows were identified and divided into scale factors and technical factors. Based on that and taking indices such as the quantities of lead production and recovered lead scraps, and lead recycling rate and emission rates as the scale and technical indices, respectively, the reasons for the changes of lead flow in our country were analyzed from the aspects of consumption, trade, technology, management and so on. The results showed: the domestic consumption of lead products has been gro wing quickly at an average annual rate of 24.7%, which pulled the growth of domestic lead consumption; The growth of lead consumption further increased the growth of lead production at an average annual rate of 14.2%, which finally pulled the growth of domestic lead ore resource consumption, lead concentrates net imports and lead scraps recovering; The increases in domestic consumption ratio of final lead products promoted the improvement of the lead recycling rate; As national management was strengthened, most lead-enterprises with small scale and old-dated technologies were closed, meanwhile, some advanced technologies were encouraged to be employed, thus the general resource utilization rate was improved and environmental lead emissions rate was reduced.

[Quantitative analysis on the changes in anthropogenic lead flows of China].

In recent years, a series of measures have been taken to improve the lead anthropogenic flow. Knowledge of the changes that happened to anthropogenic lead flows can not only examine the effectiveness of these measures, but also help us to understand the current status of lead flows in China, which can provide us quantitative fundamental reference for further improvement in source utilization and environment quality. In this study, the material flow analysis method based on stock and flow (STAF) was employed to analyze the current anthropogenic lead flows in 2010. Based on that, some indices such as lead ore consumption, environmental lead emission, resource efficiency, environmental efficiency, recycling rate, and so on, were taken to evaluate the changes occurred to anthropogenic lead flows during the last decade by comparing their values in 2010 to those in 2000. The results showed that the lead resource efficiency and environmental efficiency in 2010 were 1.3 times and 1.07 times respectively as high as those of 2000, while the lead recycling rate was also increased by 29.57%. However, the quantity of lead ore consumption and environmental lead emissions continued increasing, and were increased by 1.97 and 2.57 times respectively as compared to those of 2000 due to the scale expansion of China in lead production and consumption, which indicates a future heavy task in the improvement of anthropogenic lead flows of China.

[Speciation analysis of lead losses from anthropogenic flow in China].

Lead pollutants in the environment origin from lead losses in the anthropogenic lead cycle, and the diversity of lead loss species indicates different starting points for transferring and transformation in the environmental medium. The knowledge of lead lose species from anthropogenic flow can help lay a scientific and sound foundation for future environmental risk assessment and source management. The anthropogenic lead flow was tracked down in the research, and with the methodology of physical and chemical analysis, the species of lead losses in all life-cycle stages were recognized. The year 2010 was used as a case study for quantitative speciation analysis of total lead losses. It turns out that PbSO4 is most, which contributes 23.4% of the total losses; followed by PbO, Pb and PbCO3, and these three species together occupy 46.2%. In addition, for every 1 kt refined lead consumed domestically, lead losses total 547.9 t, of which 73.3% are from use and waste management & recycling. In view of speciation, PbSO4 is 128.2 t and mainly occurs in production and waste management & recycling; while most PbO, Pb and PbCO3 are separately from waste management & recycling, use and production.

[Method for grading industrial sectors in energy consumption and its application].

Energy is mainly consumed by the urban industry system, thus grading industrial sectors for their energy consumption may help to identify the concerned industrial sectors and provide necessary information for industrial energy management in China's industrialization and urbanization. In present article, based on a review of the fundamental relationships between energy consumption and industrial sectors, the contribution rates and energy efficiency of industrial sectors are chosen as typical parameters for energy consumption. The concept of distance index of industrial sectors for energy consumption is defined through China's average level as a reference base. The grade of industrial sectors in energy consumption is classed into 9 types from extreme advantage to extreme disadvantage according to the scope of distance index values, and the types of industrial sectors that need to be more concerned are pointed out. Taking Chongqing as a case study, the application for grading industrial sectors for their energy consumption was exhibited, by which, the main industrial sectors are grated and the industrial sectors that should be special concerned in energy management are determined.

[Eco-efficiency of Jiaozuo industry sectors].

Jiaozuo city was taken as a representative industry city and its industry energy consumption and industry emissions such as wastewater,solid waste, SO2, dust and so on were selected as corresponding environmental loads. The contribution rate to the environmental loads and eco-efficiencies of Jiaozuo industry sectors were analyzed quantitatively. The results show that, the industry sector with the highest energy eco-efficiency is Mining and Processing of Ferrous Metal Ores (FMM), 43.19 x 10(4) yuan x tce(-1), and its contribution rate is 0.003%; the one with the highest wastewater-related eco-efficiency is Manufacture of Transport Equipment (TRM), 3.58 x 10(4) yuan x t(-1), and its contribution rate is 0.0001%; the one with the highest solid waste-related eco-efficiency is Manufacture of Special Purpose Machinery( SMM), 323.22 x 10(4) yuan x t(-1), and its contribution rate is 0.005%; the one with the highest SO2 emission-related eco-efficiency is Manufacture of Special Purpose Machinery (SMM), 19.74 x 10(4) yuan x kg(-1), and its contribution rate is 0.0001%; the one with the highest dust emission-related eco-efficiency is Manufacture of Rubber (RUM), 6.75 x 10(4) yuan x kg(-1), and its contribution rate is 0.001%. It can be seen that the industry sector with high value of eco-efficiency always contributes less to its environmental load, which results that the industry sectors with high eco-efficiencies only play a weak role in leading the overall industry eco-efficiency. A succinct distance index (SDI) was proposed to estimate the differences between Jiaozuo and China average for their eco-efficiency of every industrial sector. The values of SDI range from -1 to 63.45, and the absolute value of SDI with positive value is much greater than that with negative value, which indicates that the values of eco-efficiencies for the advanced industry sectors of Jiaozuo city are much higher than those for China's industry sectors average.

[Eco-efficiency of industry sectors for China].

Industry is the main source of resource consumption and environmental emissions of China, and the analyzing of eco-efficiencies for industrial sectors may provide essential information for the restructure of industrial system and the improvement of environmental quality of China. The industry composition was analyzed and the relationship between the industry and its environment was established. The energy consumption and the main environmental emissions such as wastewater, solid waste, industry SO2, smog, dust were chosen as the environmental impact categories, the corresponding eco-efficiencies of industry were defined and estimated for China in 2007. The results are as follows: the energy efficiency is 615.5 x 10(4) yuan x ktce(-1), the wastewater and solid waste related eco-efficiencies are 54.3 x 10(4) yuan x kt(-1) and 1.9 x 10(4) yuan x t(-1), respectively; industry SO2, smog, dust related eco-efficiencies are 59.6 x 10(4), 169.2 x 10(4) and 184.6 x 10(4) yuan x t(-1), respectively. The eco-efficiencies of 39 industry sectors were analyzed extensively and the results showed that, the distribution of industrial sectors in above eco-efficiencies is uneven, and the order of industrial sector in industry will vary with industry sector and eco-efficiency category. Meanwhile, for the same category of eco-efficiency, the values for different industry sectors may change from centuplicate to several thousand folds, therefore a great possibility for the improvement of industry eco-efficiency is exist in the restructure of industry system.