Preliminary Research on Regional Material Flow Analysis:A Case Study of Chengyang District in Qingdao

The method ＂Material Flow Analysis （MFA）＂ is one of the effective tools to study law and quantification of material flow between economic system and ecological system. On the national level, economy-wide material flow analysis has been published for a number of countries. However, published studies on the regional or local level are still very limited and a standardized method does not exist yet. On the basis of framework of Material Flow Analysis proposed by Eurostat, the paper collected related data and analyzed material input and output for the Chengyang district in Qingdao. The results showed that DMI （Direct Material Input） and TMR （Total Material Requirement） in absolute number increased about 3.6 and 3.9 times, respectively from 1995 to 2004. Fossil fuel and mineral contributed to about 50.3%-76.3% of DMI. Imports of material increased about 5.0 times and became the most important Contributor to DMI, which showed that local economic growth was highly dependent on resources from other regions and countries. DPO （Domestic Processed Output） and TDO （Total Domestic Output） represent slow increasing trend, and DPO contributed to 22.2%-58.1% of TDO, suggesting local hidden flows were of obvious effect on TDO. The biggest component of DPO is CO2, approximately accounting for 90% of DPO. The material productivity increased 57.7% in last decade, reflecting improvement of efficiency of resources utilization in some extent. However, compared to developed countries and regions, material productivity of Chengyang district was relatively low. Therefore, in order to promote the sustainability, it is essential to develop circular economy and enhance materials productivity.

Current status and future trends for material flow analysis applications at CSC

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 CO_2 and energy intensity of coke making,sintering,and BF processes.This MFA model was used to analyze the CO_2 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.

Enhancing wood efficiency through comprehensive wood flow analysis:Methodology and strategic insights

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.

End-of-life batteries management and material flow analysis in South Korea

Consumers increasingly have worn-out batteries as electrical and electronic equipment with new technical developments are introduced into the market and quickly replace older models. As a result, large amounts of end-of-life （EOL） or waste batteries are generated. Such batteries may contain a variety of materials that includes valuable resources as well as toxic elements. Thus, the proper recycling and management of batteries is very important from the perspective of resource conservation and environmental effect. The collection and recycling of EOL batteries is relatively low in South Korea compared to other countries, although an extended producer responsibility （EPR） policy was adopted for battery recycling in 2003. In this study, the management and material flow of EOL batteries is presented to determine potential problems and quantitative flow, based on literature review, site visits to battery recycling facilities, and interviews with experts in the Korea Battery Recycling Association （KBRA）, manufacturers, and regulators in government. The results show that approximately 558 tons of manganese-alkaline batteries, the largest fraction among recycling target items, was disposed in landfills or incinerators in 2015, while approximately 2,000 tons of batteries were recovered at a recycling facility by simple sorting and crushing processes. By raising environmental awareness, more diverse and effective collection systems could be established for consumers to easily dispose of EOL batteries in many places. Producers, retailers and distributors in South Korea should also play an important role in the collection of EOL batteries from consumers. Lithium-ion batteries from many electronic devices must be included in the EPR system for resource recovery.

Material flow analysis(MFA)of an eco-economic system:a case study of Wujin District,Changzhou,China

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.

Exploring the potential for improving material utilization efficiency to secure lithium supply for China's battery supply chain

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.

Estimation and prediction of plastic waste annual input into the sea from China

Marine plastic debris has been a pervasive issue since the last century, and research on its sources and fates plays a vital role in the establishment of mitigation measures. However, data on the quantity of plastic waste that enters the sea on a certain timescale remain largely unavailable in China. Here, we established a model using material flow analysis method based on life cycle assessment to follow plastic product from primary plastic to plastic waste with statistical data and monitoring data from accurate sources. This model can be used to estimate and forecast the annual input of plastic waste into the sea from China until 2020. In 2011, 0.547 3-0.751 5 million tons of plastic waste entered the seas in China, with a growth rate of 4.55% per year until 2017. And the amount will decrease to 0.257 1 to 0.353 1 million tons in 2020 under the influence of governmental management. The amount of plastic waste discharged from coastal areas calculated in this study was much larger than that from river, thus it is suggested to strengthen the governance and control of plastic waste in coastal fishery activities in China in order to reduce the amount of marine plastic waste input.

Sulfur Flow Analysis for New Generation Steel Manufacturing Process

Sulfur flow for new generation steel manufacturing process is analyzed by the method of material flow analysis, and measures for SO2 emission reduction are put forward as assessment and target intervention of the results. The results of sulfur flow analysis indicate that 90 % of sulfur comes from fuels. Sulfur finally discharges from the steel manufacturing route in various steps, and the main point is BF and BOF slag desulfurization. In sintering process, the sulfur is removed by gasification, and sintering process is the main source of SO2 emission. The sulfur content of coke oven gas （COG） is an important factor affecting SO2 emission. Therefore, SO2 emission reduction should be started from the optimization and integration of steel manufacturing route, sulfur burden should be reduced through energy saving and consumption reduction, and the sulfur content of fuel should be controlled. At the same time, BF and BOF slag desulfurization should be optimized further and coke oven gas and sintering exhausted gas desulfurization should be adopted for SO2 emission reduction and reuse of resource, to achieve harmonic coordination of economic, social, and environmental effects for sustainable development.

Sustainable Intensification of Cultivated Land Use and Its Influencing Factors at the Farming Household Scale: A Case Study of Shandong Province, China

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.

Dynamic phosphorus budget for lake-watershed ecosystems

Lake eutrophication caused by excess phosphorus （P） loading from point sources （PS） and nonpoint sources （NPS） is a persistent and serious ecological problem in China. A phosphorus budget, based on material flow analysis（MFA） and system dynamic （SD）, is proposed and applied for the agriculture-dominated Qionghai Lake watershed located in southwestern China. The MFA-SD approach will not only cover the transporting process of P in the lake-watershed ecosystems, but also can deal with the changes of P budget due to the dynamics of watershed. P inflows include the fertilizer for agricultural croplands, soil losses, domestic sewage discharges, and the atmospheric disposition such as precipitation and dust sinking. Outflows are consisted of hydrologic export, water resources development, fishery and aquatic plants harvesting. The internal P recycling processes are also considered in this paper. From 1988 to 2015, the total P inflows for Lake Qionghai are in a rapid increase from 35.65 to 78.73 t/a, which results in the rising of P concentration in the lake. Among the total P load 2015, agricultural loss and domestic sewage account for 70.60% and 17.27% respectively, directly related to the rapid social-economic development and the swift urbanization. Future management programs designed to reduce P inputs must be put into practices in the coming years to ensure the ecosystem health in the watershed.

The Building of Papermaking Enterprise's Recycling Economy Evaluation Index System Based on Value Flow Analysis

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.

Characteristics of metal flow in cold extrusion under electric-hydraulic chattering

An experimental setup for cold extrusion process with electric-hydraulic chattering was developed and its working principle was introduced. The finite element （FE） model for a kind of cup part （material： 20Cr） was built by using the software Deform-3D. FE simulation experiments with and without electric-hydraulic chattering were carried out to analyze the velocity fields and the metal grid flow lines. The extrusion ex- periments of the cup part were also performed under different conditions. The difference of metal flow lines with and without electric-hydraulic chattering was discussed via a scanning electron microscope （SEM） and the Keyence super-depth three-dimensional microscopic system. The results showed that with the electric-hydraulic chattering, the velocity of material flow increases, whereas deformation resistance decreases. Electric hydraulic chattering results in easy metal flow, small bending degree of metal flow lines, slender and dense metal grains, and thereby an improved quality of the deformed parts.

Win-Win:Anthropogenic circularity for metal criticality and carbon neutrality

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.

Spatiotemporal evolution and driving factors for GHG emissions of aluminum industry in China

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.

Occurrence of antibiotics in typical pig farming and its wastewater treatment in Thailand

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.

Sinks of steel in China-addition to in-use stock, export and loss

China has become the largest producer of crude steel in the world since 1996, which places the country under huge pressure in terms of resources, energy, and the environment. Examining the driver of steel demand is of great significance to the structural adjustment and sustainable development of the steel industry. The researchers calculate the steel demand in China from 2000 to 2009 based on three sinks （steel stock, export, and loss） by taking the four stages of steel life cycle （production, fabrication and manufacturing, use, and waste manage- ment and recycling） as the study object. The researchers conclude that addition to in-use stock is the main driver of steel demand and that the 10-year average addition to in- use stock accounted for 77% of the steel sinks, in which 55% of the addition occurs in the building sector, and the steel for this segment is of low strength with large consumption. Based on the analysis of existing policies, the researchers propose that the steel demand structure will develop toward diversification and that the building sector will realize the upgrade of products as soon as possible to improve construction quality. Under the pressure of rising cost for imported resources, the export ratio of steel products should be controlled appropriately. Thus, recy- cling economy should be developed to reduce steel losses.

Temporal Causal Relationship between Resource Use and Economic Growth in East China

The present paper attempts to combine cointegration theory and the material flow analysis approach to examine the causal relationship between resource use and real GDP in Jiangsu Province in East China. The study considers the period from 1990 to 2007. We use direct material input as the proxy variable for resource use. Our estimation indicates that real GDP and resource use are cointegrated and there is only unidirectional long-run Granger causality running from resource use to real GDP, but not vice versa. The estimation results mean that resources are a limiting factor in terms of economic growth, and, therefore, strategies should be adopted for more vigorous economic development and consistent resource use in East China. Furthermore, the novel idea and methodology involved in the present study can be readily extended to cover other regions for the analysis of the relationship between resource use and economic growth.

Life cycle assessment of urban uses of biochar and case study in Uppsala,Sweden

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.

Improvement potential of today＇s WEEE recycling performance： The case of LCD TVs in Belgium

Waste of electrical and electronic equipment （WEEE） constitutes one of the most relevant waste streams because of the quantity and presence of valuable materials. However, there is limited knowledge on the resource potential of urban mining WEEE, as data on material composition, and the efficiency of current recycling treatments are still scarce. In this article, an evaluationof the recycling performance at a national level for one of the fastest growing e-waste streams： LCD TVs is carried out through the following four steps. Firstly, material characterisation is performed by means of sampling of the waste stream. Secondly, a material flow analysis is conducted by evaluating the separation performance of a recycling plant in Belgium..Thirdly, the recovered economic value and avoided environmental impact （EI） of the analysed recycling system is assessed. Finally, the potential of urban mining for Belgium is forecasted. The analysis shows that while recycling performance for ferrous metals and aluminium are relatively high; there is substantial room to better close the material loops for precious metals （PM） and plastics. PMs and plastics account for 66 % of the economic value in LCD TVs and 57% of the El. With the current, commonly applied recycling technology only one-third of the PM and housing plastics are recycled; meaning that for＇these material＇s, at a national level for Belgium, there is a potential for improvement that represents 3.3 million euros in 2016 and 6.8 million euros in 2025.

In-use product and steel stocks sustaining the urbanization of Xiamen, China

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.