Material Flow Analysis（MFA） is a crucial instrument for sustainable development and creating industrial ecology system.MFA studies could balance and analyze the sources,flows,and consumes of specific materials or su...Material Flow Analysis（MFA） is a crucial instrument for sustainable development and creating industrial ecology system.MFA studies could balance and analyze the sources,flows,and consumes of specific materials or substances.The results of MFA studies could support the strategies or decisions making for energy, resource,and waste management,especially achieving sustainable resource management.At CSC,the dynamic simulating software,STELLA,is used to develop a MFA model for scenario analysis.CSC also uses the freeware STAN 2.0 as a tool for visualizing and simulating material flows and stocks.Case studies of greenhouse gases MFA for integrated steel works are conducted.The results showed that the carbon content of hot-metal is an important hidden flow for balance analysis,and the different GHG emission scenarios and mitigation action scenarios are assessed.In addition,the Iron-making GHG I/O MFA Model,based on worldsteel Global Steel Sector Approach（GSSA）,is developed for calculating the CO2 and energy intensity of coke making,sintering,and BF processes.This MFA model was used to analyze the CO2 reduction potential for iron-making process.The cases conducted for MFA applications at CSC were such as greenhouse gas,zinc,etc.In the future,CSC is going to develop a 'CSC Environment Management and Decision Supporting System' which combine MFA,LCA（life cycle assessment）,and environment risk assessment.This supporting system expects to promoting energy efficiency and best resource use,supporting environment policymaking,creating environmental information value,etc.展开更多
The economic and ecological aspects of a social system are coherently linked and can be examined by its material and energy flows.In this study,we used the material flow analysis(MFA)to model the material input and ou...The economic and ecological aspects of a social system are coherently linked and can be examined by its material and energy flows.In this study,we used the material flow analysis(MFA)to model the material input and output of the Wujin District of Changzhou City,Jiangsu Province in China.It was revealed that:(1)total material input and material input per capita increased with economic development,while the total material out-put and material output per capita decreased consistently;(2)except for water,the total material input continued to increase.Input of solid materials grew faster than that of gaseous materials,while the total material output declined.The gas output accounted for the largest pro-portion of the output resulting in primary environmental pollution as burned fossil fuel;(3)water use in agriculture continued with an increasing trend while that in industrial and residential sectors decreased per capita.The total wastewater discharge and wastewater discharge per capita decreased with a faster decreasing rate of residential was-tewater discharge followed by industrial wastewater discharge;(4)material input per unit GDP fluctuated and material output per unit GDP decreased.A decreasing trend in both water use and wastewater discharge per unit GDP was disclosed.These results suggest that the efficiency of resource use in the Wujin District has improved.This weakened the direct link between economic development and environmental deterioration.Additionally,we discussed the harmonic development between environment and economy.Potential limitations of MFA’s application were also discussed.It is suggested that effective measures should be taken for the enforcement of cir-cular economic strategies and the construction of a resource-saving economy.展开更多
Wood,an essential natural resource in human civilization,remains widely used despite advances in technology and material substitution.The surge in greenhouse gas emissions and environmental concerns accentuates the ne...Wood,an essential natural resource in human civilization,remains widely used despite advances in technology and material substitution.The surge in greenhouse gas emissions and environmental concerns accentuates the need for optimizing wood utilization.Material flow analysis is a powerful tool for tracking material flows and stocks,aiding resource management and environmental decision-making.However,the full extent of its methodological dimensions,particularly within the context of the wood supply chain,remains relatively unexplored.In this study,we delve into the existing literature on wood flow analysis,discussing its primary objectives,materials involved,temporal and spatial scales,data sources,units,and conversion factors.Additionally,data uncertainty,data reconciliation and crucial assumptions in material flow analysis are highlighted in this paper.Key findings reveal the significance of wood cascading and substitution effects by replacing non-wood materials,where they can reduce greenhouse gas emissions more than the natural carbon sink of forests and wood products.The immediate impact of short-term wood cascading might not be as robust as the substitution effect,with energy substitution showcasing better results than material substitution.However,it's crucial to note that these conclusions could experience significant reversal from a long-term and global perspective.Strategies for improving wood efficiency involve maximizing material use,advancing construction technologies,extending product lifespans,promoting cascade use,and optimizing energy recovery processes.The study underscores the need for standardized approaches in wood flow analysis and emphasizes the potential of wood efficiency strategies in addressing environmental challenges.展开更多
Lithium-ion battery(LIB)is the key technology for climate change mitigation.The sustainability of LIB supply chain has caused widespread concern since the material utilization efficiency of LIB supply chain has not be...Lithium-ion battery(LIB)is the key technology for climate change mitigation.The sustainability of LIB supply chain has caused widespread concern since the material utilization efficiency of LIB supply chain has not been well investigated.This study aims to fill this research gap by conducting a dynamic material flow analysis of lithium in China from 2015 to 2021.Results indicate that within the temporal boundary,lithium flow and in-use stock grew significantly in China due to the rapid development of the EV market,with lithium flow in domestic production of basic chemicals increasing by 614%to 100 kt,end-use consumption increasing by 160%to 35 kt,and in-use stock increasing by 62%to 195 kt.China has been a net importer of lithium,of which cumulative imports and exports were 343 kt and 169 kt,respectively.In addition,103 kt of lithium was converted to inventories or was lost during the processing from 2015 to 2021.By optimizing inventory and processing,developing substitutes for lithium for non-battery applications,and improving lithium recycling,China's net import dependency of lithium could be reduced from 27%-86%to 0%-16%.Our study demonstrates that it is urgent to improve material utilization efficiency so that the lithium resource supply can be secured.展开更多
Promoting the sustainable intensification of cultivated land use(SICL) has become crucial for ensuring a sufficient supply of grain and important agricultural products, as well as for the sustainable use of resources....Promoting the sustainable intensification of cultivated land use(SICL) has become crucial for ensuring a sufficient supply of grain and important agricultural products, as well as for the sustainable use of resources. Taking widely used areas of Shandong Province in China as examples, an analytical scale and level framework for SICL is constructed in this study. It measures the level of SICL through material flow analysis, constructs Tobit models to analyze the influencing factors of SICL at the farming household scale,and analyzes the transition mechanisms of SICL. The results show that the overall level of SICL in Shandong Province is low, and the spatial distribution is uneven. There are relatively more farmers participating in unsustainable intensification than in medium or low levels of SICL, with farmers working at a high level of SICL making up the smallest proportion. The factors that determine the level of SICL at which farmers work vary significantly. More male farmers operate at a low SICL level than female farmers, while females outnumber males at a high SICL level. This is mainly related to the regional distribution of age and population. Meanwhile, with larger cultivated land areas, there is a lower degree of land fragmentation, with a higher level of SICL corresponding to a smaller distance to the nearest town closer within 1–5 km from the town center. We can see the level of SICL and its processes themselves are closely related to time and space scales. Based on the above analysis, it is necessary to clarify the standard processes of SICL to adapt them to local conditions. This includes instructing managers on how to improve resource utilization, increase the sustainable development of cultivated land and establish a comprehensively efficient and functional SICL mechanism. The sustainable intensification of cultivated land use and its specific application in the new era are conducive to enriching the frontier theories and methodology of sustainable development, and are of great significance to the advancement of green agriculture and the decision-making of rural high-quality development.展开更多
At present,the research on circular economy has made a lot of substantive results both at home and abroad.But for the papermaking enterprise,which is the representative of the light industry,few studies have analyzed ...At present,the research on circular economy has made a lot of substantive results both at home and abroad.But for the papermaking enterprise,which is the representative of the light industry,few studies have analyzed the evaluation index system of circular economy.Since the current material flow analyses have limitations that the researchers cannot calculate materials with different units.The authors take advantage of the intrinsic correlation between the basic principle of value flow analysis and circular economy,and then analyze the dynamic changes of material flow and value flow through enterprises internal production process.Considering the resource output,the authors set up the layered structure of the evaluation index system,and then preliminarily determine the index form.Next,the authors use the frequency statistics analysis method to adjust indicators,forming a preliminary index system.After that,the principal component analysis and independent analysis are applied for screening.Finally,the authors build a circular economy evaluation index system for papermaking enterprise to provide scientific guidance for the process of circular economy.展开更多
Resource depletion and environmental degradation have fueled a burgeoning discipline of anthropogenic circularity since the 2010s.It generally consists of waste reuse,remanufacturing,recycling,and recovery.Circular ec...Resource depletion and environmental degradation have fueled a burgeoning discipline of anthropogenic circularity since the 2010s.It generally consists of waste reuse,remanufacturing,recycling,and recovery.Circular economy and“zero-waste”cities are sweeping the globe in their current practices to address the world’s grand concerns linked to resources,the environment,and industry.Meanwhile,metal criticality and carbon neutrality,which have become increasingly popular in recent years,denote the material's feature and state,respectively.The goal of this article is to determine how circularity,criticality,and neutrality are related.Upscale anthropogenic circularity has the potential to expand the metal supply and,as a result,reduce metal criticality.China barely accomplished 15%of its potential emission reduction by recycling iron,copper,and aluminum.Anthropogenic circularity has a lot of room to achieve a win-win objective,which is to reduce metal criticality while also achieving carbon neutrality in a near closed-loop cycle.Major barriers or challenges for conducting anthropogenic circularity are deriving from the inadequacy of life-cycle insight governance and the emergence of anthropogenic circularity discipline.Material flow analysis and life cycle assessment are the central methodologies to identify the hidden problems.Mineral processing and smelting,as well as end-of-life management,are indicated as critical priority areas for enhancing anthropogenic circularity.展开更多
China’s aluminum(Al)production has released a huge amount of greenhouse gas(GHG)emissions.As one of the biggest country of primary Al production,China must mitigate its overall GHG emission from its Al industry so th...China’s aluminum(Al)production has released a huge amount of greenhouse gas(GHG)emissions.As one of the biggest country of primary Al production,China must mitigate its overall GHG emission from its Al industry so that the national carbon neutrality target can be achieved.Under such a background,the study described in this paper conducts a dynamic material flow analysis to reveal the spatiotemporal evolution features of Al flows in China from 2000 to 2020.Decomposition analysis is also performed to uncover the driving factors of GHG emission generated from the Al industry.The major findings include the fact that China’s primary Al production center has transferred to the western region;the primary Al smelting and carbon anode consumption are the most carbonintensive processes in the Al life cycle;the accumulative GHG emission from electricity accounts for 78.14% of the total GHG emission generated from the Al industry;China’s current Al recycling ratio is low although the corresponding GHG emission can be reduced by 93.73% if all the primary Al can be replaced by secondary Al;and the total GHG emission can be reduced by 88.58% if major primary Al manufacturing firms are transferred from Inner Mongolia to Yunnan.Based upon these findings and considering regional disparity,several policy implications are proposed,including promotion of secondary Al production,support of clean electricity penetration,and relocation of the Al industry.展开更多
This study investigated antibiotics in pig feed and drinking water and their excretion together with manure and wastewater at a typical pig farm in Thailand.Among the 21 antibiotics analyzed,tetracyclines,macrolides,b...This study investigated antibiotics in pig feed and drinking water and their excretion together with manure and wastewater at a typical pig farm in Thailand.Among the 21 antibiotics analyzed,tetracyclines,macrolides,b-lactams,aminoglycosides,quinolones,sulfonamides,pleuromutilin,and florfenicol classes,were found as active ingredients in feed and drinking water and excreted together with pig wastes.Among them,doxycycline,tilmicosin,and amoxicillin were detected higher concentrations in wastewater(12.9e459.1 mg L^(-1)),sediment(0.074e0.62 mg kg^(-1)),and pig manure(0.45e4.1 mg kg^(-1)).During wastewater treatment,those major antibiotics were remaining in pond water and settled sludge up to 79.5 mg L-1 and 24.2 mg kg^(-1),respectively.The normalized excretion mass of total antibiotics was determined as 11.2 mg head-1 day-1,contributed mainly from doxycycline(5.9 mg head-1 day-1),tilmicosin(2.8 mg head-1 day-1),and amoxicillin(2.2 mg head-1 day-1).Based on total pig production in Thailand,the excreted mass of antibiotics was estimated at 79.3 tons year-1.展开更多
Biochar is a material derived from biomass pyrolysis that is used in urban applications.The environmental impacts of new biochar products have however not been assessed.Here,the life cycle assessments of 5 biochar pro...Biochar is a material derived from biomass pyrolysis that is used in urban applications.The environmental impacts of new biochar products have however not been assessed.Here,the life cycle assessments of 5 biochar products(tree planting,green roofs,landscaping soil,charcrete,and biofilm carrier)were performed for 7 biochar supply-chains in 2 energy contexts.The biochar products were benchmarked against reference products and oxidative use of biochar for steel production.Biochar demand was then estimated,using dynamic material flow analysis,for a new city district in Uppsala,Sweden.In a decarbonised energy system and with high biochar stability,all biochar products showed better climate performance than the reference products,and most applications outperformed biomass use for decarbonising steel production.The climate benefits of using biochar ranged from−1.4 to−0.11 tonne CO_(2)-eq tonne−1 biochar in a decarbonised energy system.In other environmental impact categories,biochar products had either higher or lower impacts than the reference products,depending on biochar supply chain and material substituted,with trade-offs between sectors and impact categories.However,several use-phase effects of biochar were not included in the assessment due to knowledge limitations.In Uppsala’s new district,estimated biochar demand was around 1700 m^(3)year^(−1)during the 25 years of construction.By 2100,23%of this biochar accumulated in landfill,raising questions about end-of-life management of biochar-containing products.Overall,in a post-fossil economy,biochar can be a carbon dioxide removal technology with benefits,but biochar applications must be designed to maximise co-benefits.展开更多
Introduction:In-use product and material stocks are the amount of concerned manufactured products and materials in active use,and are essential components of urban ecosystem.Methods:This study estimates the dynamic in...Introduction:In-use product and material stocks are the amount of concerned manufactured products and materials in active use,and are essential components of urban ecosystem.Methods:This study estimates the dynamic in-use stocks of steel-containing products and steel in the city of Xiamen,China,during 1980–2015 by applying a bottom-up accounting approach.We incorporate 55 categories of steel-containing products that are classified into five end-use sectors(i.e.,buildings,infrastructure,transportation equipment,machinery,and domestic appliances).Outcomes and Discussion:In-use stocks of 51%of the studied products kept increasing during 1980–2015,especially after 2000.Steel stocks have grown up to 4.9±1.4 tons per capita(t/cap)in 2015,from 0.5±0.2 t/cap in 1980.Buildings are the largest reservoirs,although its share decreased from 89%in 1980 to 68%in 2015.The dynamic spatial distribution indicates that steel stocks gradually expanded from urban core to suburban areas.Conclusion:Theresults help to explore how a city’s urbanization is sustained by the in-use stocks growth.In-use steel stocks,of which the growth is highly correlated to and probably driven by the population growth,GDP increase,and urban built-up area expansion,may serve as a supplementary indicator for urbanization.展开更多
文摘Material Flow Analysis（MFA） is a crucial instrument for sustainable development and creating industrial ecology system.MFA studies could balance and analyze the sources,flows,and consumes of specific materials or substances.The results of MFA studies could support the strategies or decisions making for energy, resource,and waste management,especially achieving sustainable resource management.At CSC,the dynamic simulating software,STELLA,is used to develop a MFA model for scenario analysis.CSC also uses the freeware STAN 2.0 as a tool for visualizing and simulating material flows and stocks.Case studies of greenhouse gases MFA for integrated steel works are conducted.The results showed that the carbon content of hot-metal is an important hidden flow for balance analysis,and the different GHG emission scenarios and mitigation action scenarios are assessed.In addition,the Iron-making GHG I/O MFA Model,based on worldsteel Global Steel Sector Approach（GSSA）,is developed for calculating the CO2 and energy intensity of coke making,sintering,and BF processes.This MFA model was used to analyze the CO2 reduction potential for iron-making process.The cases conducted for MFA applications at CSC were such as greenhouse gas,zinc,etc.In the future,CSC is going to develop a 'CSC Environment Management and Decision Supporting System' which combine MFA,LCA（life cycle assessment）,and environment risk assessment.This supporting system expects to promoting energy efficiency and best resource use,supporting environment policymaking,creating environmental information value,etc.
文摘The economic and ecological aspects of a social system are coherently linked and can be examined by its material and energy flows.In this study,we used the material flow analysis(MFA)to model the material input and output of the Wujin District of Changzhou City,Jiangsu Province in China.It was revealed that:(1)total material input and material input per capita increased with economic development,while the total material out-put and material output per capita decreased consistently;(2)except for water,the total material input continued to increase.Input of solid materials grew faster than that of gaseous materials,while the total material output declined.The gas output accounted for the largest pro-portion of the output resulting in primary environmental pollution as burned fossil fuel;(3)water use in agriculture continued with an increasing trend while that in industrial and residential sectors decreased per capita.The total wastewater discharge and wastewater discharge per capita decreased with a faster decreasing rate of residential was-tewater discharge followed by industrial wastewater discharge;(4)material input per unit GDP fluctuated and material output per unit GDP decreased.A decreasing trend in both water use and wastewater discharge per unit GDP was disclosed.These results suggest that the efficiency of resource use in the Wujin District has improved.This weakened the direct link between economic development and environmental deterioration.Additionally,we discussed the harmonic development between environment and economy.Potential limitations of MFA’s application were also discussed.It is suggested that effective measures should be taken for the enforcement of cir-cular economic strategies and the construction of a resource-saving economy.
基金The China Scholarship Council finances this research (Grant number CSC202010220001)。
文摘Wood,an essential natural resource in human civilization,remains widely used despite advances in technology and material substitution.The surge in greenhouse gas emissions and environmental concerns accentuates the need for optimizing wood utilization.Material flow analysis is a powerful tool for tracking material flows and stocks,aiding resource management and environmental decision-making.However,the full extent of its methodological dimensions,particularly within the context of the wood supply chain,remains relatively unexplored.In this study,we delve into the existing literature on wood flow analysis,discussing its primary objectives,materials involved,temporal and spatial scales,data sources,units,and conversion factors.Additionally,data uncertainty,data reconciliation and crucial assumptions in material flow analysis are highlighted in this paper.Key findings reveal the significance of wood cascading and substitution effects by replacing non-wood materials,where they can reduce greenhouse gas emissions more than the natural carbon sink of forests and wood products.The immediate impact of short-term wood cascading might not be as robust as the substitution effect,with energy substitution showcasing better results than material substitution.However,it's crucial to note that these conclusions could experience significant reversal from a long-term and global perspective.Strategies for improving wood efficiency involve maximizing material use,advancing construction technologies,extending product lifespans,promoting cascade use,and optimizing energy recovery processes.The study underscores the need for standardized approaches in wood flow analysis and emphasizes the potential of wood efficiency strategies in addressing environmental challenges.
基金This study is sponsored by the National Key R&D Program of China(2019YFC1908501)National Natural Science Foundation of China(72122010,71774100,72088101,71810107001).
文摘Lithium-ion battery(LIB)is the key technology for climate change mitigation.The sustainability of LIB supply chain has caused widespread concern since the material utilization efficiency of LIB supply chain has not been well investigated.This study aims to fill this research gap by conducting a dynamic material flow analysis of lithium in China from 2015 to 2021.Results indicate that within the temporal boundary,lithium flow and in-use stock grew significantly in China due to the rapid development of the EV market,with lithium flow in domestic production of basic chemicals increasing by 614%to 100 kt,end-use consumption increasing by 160%to 35 kt,and in-use stock increasing by 62%to 195 kt.China has been a net importer of lithium,of which cumulative imports and exports were 343 kt and 169 kt,respectively.In addition,103 kt of lithium was converted to inventories or was lost during the processing from 2015 to 2021.By optimizing inventory and processing,developing substitutes for lithium for non-battery applications,and improving lithium recycling,China's net import dependency of lithium could be reduced from 27%-86%to 0%-16%.Our study demonstrates that it is urgent to improve material utilization efficiency so that the lithium resource supply can be secured.
基金Under the auspices of the National Natural Science Foundation of China(No.41671176,42071226)Liaoning Revitalization Talents Program(No.XLYC1807060)。
文摘Promoting the sustainable intensification of cultivated land use(SICL) has become crucial for ensuring a sufficient supply of grain and important agricultural products, as well as for the sustainable use of resources. Taking widely used areas of Shandong Province in China as examples, an analytical scale and level framework for SICL is constructed in this study. It measures the level of SICL through material flow analysis, constructs Tobit models to analyze the influencing factors of SICL at the farming household scale,and analyzes the transition mechanisms of SICL. The results show that the overall level of SICL in Shandong Province is low, and the spatial distribution is uneven. There are relatively more farmers participating in unsustainable intensification than in medium or low levels of SICL, with farmers working at a high level of SICL making up the smallest proportion. The factors that determine the level of SICL at which farmers work vary significantly. More male farmers operate at a low SICL level than female farmers, while females outnumber males at a high SICL level. This is mainly related to the regional distribution of age and population. Meanwhile, with larger cultivated land areas, there is a lower degree of land fragmentation, with a higher level of SICL corresponding to a smaller distance to the nearest town closer within 1–5 km from the town center. We can see the level of SICL and its processes themselves are closely related to time and space scales. Based on the above analysis, it is necessary to clarify the standard processes of SICL to adapt them to local conditions. This includes instructing managers on how to improve resource utilization, increase the sustainable development of cultivated land and establish a comprehensively efficient and functional SICL mechanism. The sustainable intensification of cultivated land use and its specific application in the new era are conducive to enriching the frontier theories and methodology of sustainable development, and are of great significance to the advancement of green agriculture and the decision-making of rural high-quality development.
基金supported by the National Natural Science Foundation of China (Grant No.71303263)the State Key Program of National Natural Science Foundation of China (Grant No.71431006)+6 种基金the Key Projects of Philosophy and Social Sciences of the Ministry of Education of China (Grant No.13JZD016)the Major Program of the National Social Science Foundation of China (Grant No.11&ZD166)the Humanities and Social Sciences Program Foundation of the Ministry of Education of China (Grant No.11YJC790312)the Doctoral Foundation of the Ministry of Education of China (Grant No.20130162120045)the Energysaving and Emission Reduction Demonstration Project of Changsha City (Grant No.CSCG-HNSZ-DY20131002,Procurement of [2013D] 0012-1 Changsha Finance)the Social Sciences Program Foundation of Hunan Province (Grant No.13YBA353)the Soft Science Program of Hunan Province (Grant No.2014ZK3124)
文摘At present,the research on circular economy has made a lot of substantive results both at home and abroad.But for the papermaking enterprise,which is the representative of the light industry,few studies have analyzed the evaluation index system of circular economy.Since the current material flow analyses have limitations that the researchers cannot calculate materials with different units.The authors take advantage of the intrinsic correlation between the basic principle of value flow analysis and circular economy,and then analyze the dynamic changes of material flow and value flow through enterprises internal production process.Considering the resource output,the authors set up the layered structure of the evaluation index system,and then preliminarily determine the index form.Next,the authors use the frequency statistics analysis method to adjust indicators,forming a preliminary index system.After that,the principal component analysis and independent analysis are applied for screening.Finally,the authors build a circular economy evaluation index system for papermaking enterprise to provide scientific guidance for the process of circular economy.
基金supported by the National Natural Sciences Foundation of China(No.92062111)the National Key R&D Program of China(No.2019YFC1908501).
文摘Resource depletion and environmental degradation have fueled a burgeoning discipline of anthropogenic circularity since the 2010s.It generally consists of waste reuse,remanufacturing,recycling,and recovery.Circular economy and“zero-waste”cities are sweeping the globe in their current practices to address the world’s grand concerns linked to resources,the environment,and industry.Meanwhile,metal criticality and carbon neutrality,which have become increasingly popular in recent years,denote the material's feature and state,respectively.The goal of this article is to determine how circularity,criticality,and neutrality are related.Upscale anthropogenic circularity has the potential to expand the metal supply and,as a result,reduce metal criticality.China barely accomplished 15%of its potential emission reduction by recycling iron,copper,and aluminum.Anthropogenic circularity has a lot of room to achieve a win-win objective,which is to reduce metal criticality while also achieving carbon neutrality in a near closed-loop cycle.Major barriers or challenges for conducting anthropogenic circularity are deriving from the inadequacy of life-cycle insight governance and the emergence of anthropogenic circularity discipline.Material flow analysis and life cycle assessment are the central methodologies to identify the hidden problems.Mineral processing and smelting,as well as end-of-life management,are indicated as critical priority areas for enhancing anthropogenic circularity.
基金financially supported by the National Key R&D Program of China(Grant No.2019YFC1908501)the National Natural Science Foundation of China(Grant Nos.72088101,71810107001,and 71690241)+2 种基金the Postdoctoral Science Foundation of China(Grant No.2018M641989)Philosophy and Social Science Foundation of Jiangsu Province(Grant No.2020SJA2358)the China Scholarship Council Program(Grant No.202008320101).
文摘China’s aluminum(Al)production has released a huge amount of greenhouse gas(GHG)emissions.As one of the biggest country of primary Al production,China must mitigate its overall GHG emission from its Al industry so that the national carbon neutrality target can be achieved.Under such a background,the study described in this paper conducts a dynamic material flow analysis to reveal the spatiotemporal evolution features of Al flows in China from 2000 to 2020.Decomposition analysis is also performed to uncover the driving factors of GHG emission generated from the Al industry.The major findings include the fact that China’s primary Al production center has transferred to the western region;the primary Al smelting and carbon anode consumption are the most carbonintensive processes in the Al life cycle;the accumulative GHG emission from electricity accounts for 78.14% of the total GHG emission generated from the Al industry;China’s current Al recycling ratio is low although the corresponding GHG emission can be reduced by 93.73% if all the primary Al can be replaced by secondary Al;and the total GHG emission can be reduced by 88.58% if major primary Al manufacturing firms are transferred from Inner Mongolia to Yunnan.Based upon these findings and considering regional disparity,several policy implications are proposed,including promotion of secondary Al production,support of clean electricity penetration,and relocation of the Al industry.
基金the Office of National Higher Education Science Research and Innovation Policy Council via the Program Management Unit for Human Resource&Institutional Development,Research and Innovation(PMU-B),grant number B16F630088.
文摘This study investigated antibiotics in pig feed and drinking water and their excretion together with manure and wastewater at a typical pig farm in Thailand.Among the 21 antibiotics analyzed,tetracyclines,macrolides,b-lactams,aminoglycosides,quinolones,sulfonamides,pleuromutilin,and florfenicol classes,were found as active ingredients in feed and drinking water and excreted together with pig wastes.Among them,doxycycline,tilmicosin,and amoxicillin were detected higher concentrations in wastewater(12.9e459.1 mg L^(-1)),sediment(0.074e0.62 mg kg^(-1)),and pig manure(0.45e4.1 mg kg^(-1)).During wastewater treatment,those major antibiotics were remaining in pond water and settled sludge up to 79.5 mg L-1 and 24.2 mg kg^(-1),respectively.The normalized excretion mass of total antibiotics was determined as 11.2 mg head-1 day-1,contributed mainly from doxycycline(5.9 mg head-1 day-1),tilmicosin(2.8 mg head-1 day-1),and amoxicillin(2.2 mg head-1 day-1).Based on total pig production in Thailand,the excreted mass of antibiotics was estimated at 79.3 tons year-1.
基金Sweden's innovation agency(VINNOVA)under grant number 2016-03392.
文摘Biochar is a material derived from biomass pyrolysis that is used in urban applications.The environmental impacts of new biochar products have however not been assessed.Here,the life cycle assessments of 5 biochar products(tree planting,green roofs,landscaping soil,charcrete,and biofilm carrier)were performed for 7 biochar supply-chains in 2 energy contexts.The biochar products were benchmarked against reference products and oxidative use of biochar for steel production.Biochar demand was then estimated,using dynamic material flow analysis,for a new city district in Uppsala,Sweden.In a decarbonised energy system and with high biochar stability,all biochar products showed better climate performance than the reference products,and most applications outperformed biomass use for decarbonising steel production.The climate benefits of using biochar ranged from−1.4 to−0.11 tonne CO_(2)-eq tonne−1 biochar in a decarbonised energy system.In other environmental impact categories,biochar products had either higher or lower impacts than the reference products,depending on biochar supply chain and material substituted,with trade-offs between sectors and impact categories.However,several use-phase effects of biochar were not included in the assessment due to knowledge limitations.In Uppsala’s new district,estimated biochar demand was around 1700 m^(3)year^(−1)during the 25 years of construction.By 2100,23%of this biochar accumulated in landfill,raising questions about end-of-life management of biochar-containing products.Overall,in a post-fossil economy,biochar can be a carbon dioxide removal technology with benefits,but biochar applications must be designed to maximise co-benefits.
基金This study was sponsored by the National Key Research and Development Program of Ministry of Science and Technology(2017YFC0505703)the Leading Project of Fujian Science and Technology Department(2016Y01010094)+2 种基金the Frontier Science Research Project of Chinese Academy of Sciences(QYZDB-SSW-DQC012)the Geological Surveying Project of China Geological Survey(No.121201103000150015)Wei-Qiang Chen acknowledges the Chinese Academy of Sciences Pioneer Hundred Talents Program.
文摘Introduction:In-use product and material stocks are the amount of concerned manufactured products and materials in active use,and are essential components of urban ecosystem.Methods:This study estimates the dynamic in-use stocks of steel-containing products and steel in the city of Xiamen,China,during 1980–2015 by applying a bottom-up accounting approach.We incorporate 55 categories of steel-containing products that are classified into five end-use sectors(i.e.,buildings,infrastructure,transportation equipment,machinery,and domestic appliances).Outcomes and Discussion:In-use stocks of 51%of the studied products kept increasing during 1980–2015,especially after 2000.Steel stocks have grown up to 4.9±1.4 tons per capita(t/cap)in 2015,from 0.5±0.2 t/cap in 1980.Buildings are the largest reservoirs,although its share decreased from 89%in 1980 to 68%in 2015.The dynamic spatial distribution indicates that steel stocks gradually expanded from urban core to suburban areas.Conclusion:Theresults help to explore how a city’s urbanization is sustained by the in-use stocks growth.In-use steel stocks,of which the growth is highly correlated to and probably driven by the population growth,GDP increase,and urban built-up area expansion,may serve as a supplementary indicator for urbanization.
