With the rapid development of consumer electronics and electric vehicles(EV), a large number of spent lithium-ion batteries(LIBs) have been generated worldwide. Thus, effective recycling technologies to recapture a si...With the rapid development of consumer electronics and electric vehicles(EV), a large number of spent lithium-ion batteries(LIBs) have been generated worldwide. Thus, effective recycling technologies to recapture a significant amount of valuable metals contained in spent LIBs are highly desirable to prevent the environmental pollution and resource depletion. In this work, a novel recycling technology to regenerate a LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 cathode material from spent LIBs with different cathode chemistries has been developed. By dismantling, crushing,leaching and impurity removing, the LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2(selected as an example of LiNi_xCo_yMn_(1-x-y)O_2) powder can be directly prepared from the purified leaching solution via co-precipitation followed by solid-state synthesis. For comparison purposes, a fresh-synthesized sample with the same composition has also been prepared using the commercial raw materials via the same method. X-ray diffraction(XRD), scanning electron microscopy(SEM) and electrochemical measurements have been carried out to characterize these samples. The electrochemical test result suggests that the re-synthesized sample delivers cycle performance and low rate capability which are comparable to those of the freshsynthesized sample. This novel recycling technique can be of great value to the regeneration of a pure and marketable LiNi_xCo_yMn_(1-x-y)O_2 cathode material with low secondary pollution.展开更多
The deep structure,material circulation,and dynamic processes in the Southeast Asia have long been an elusive scientific puzzle due to the lack of systematic scientific observations and recognized theoretical models.B...The deep structure,material circulation,and dynamic processes in the Southeast Asia have long been an elusive scientific puzzle due to the lack of systematic scientific observations and recognized theoretical models.Based on the deep seismic tomography using long-period natural earthquake data,in this study,the deep structure and material circulation of the curved subduction system in Southeast Asia was studied,and the dynamic processes since 100 million years ago was reconstructed.It is pointed out that challenges still exist in the precise reconstruction of deep mantle structures of the study area,the influence of multi-stage subduction on deep material exchange and shallow magma activity,as well as the spatiotemporal evolution and coupling mechanism of multi-plate convergence.Future work should focus on high-resolution land-sea joint 3-D seismic tomography imaging of the curved subduction system in the Southeast Asia,combined with geochemical analysis and geodynamic modelling works.展开更多
Recent trends in road engineering have explored the potential of incorporating recycled solid wastes into infrastructures that including pavements,bridges,tunnels,and accessory structures.The utilization of solid wast...Recent trends in road engineering have explored the potential of incorporating recycled solid wastes into infrastructures that including pavements,bridges,tunnels,and accessory structures.The utilization of solid wastes is expected to offer sustainable solutions to waste recycling while enhancing the performance of roads.This review provides an extensive analysis of the recycling of three main types of solid wastes for road engineering purposes:industrial solid waste,infrastructure solid waste,and municipal life solid waste.Industrial solid wastes suitable for road engineering generally include coal gangue,fly ash,blast furnace slag,silica fume,and steel slag,etc.Infrastructure solid wastes recycled in road engineering primarily consist of construction&demolition waste,reclaimed asphalt pavements,and recycled cement concrete.Furthermore,recent exploration has extended to the utilization of municipal life solid wastes,such as incinerated bottom ash,glass waste,electronics waste,plastic waste,and rubber waste in road engineering applications.These recycled solid wastes are categorized into solid waste aggregates,solid waste cements,and solid waste fillers,each playing distinct roles in road infrastructure.Roles of solid waste acting aggregates,cements,and fillers in road infrastructures were fully investigated,including their pozzolanic properties,integration effects to virgin materials,modification or enhancement solutions,engineering performances.Utilization of these materials not only addresses the challenge of waste management but also offers environmental benefits aiming carbon neutral and contributes to sustainable infrastructure development.However,challenges such as variability in material properties,environmental impact mitigation,secondary pollution to environment by leaching,and concerns regarding long-term performance need to be further addressed.Despite these challenges,the recycled solid wastes hold immense potential in revolutionizing road construction practices and fostering environmental stewardship.This review delves into a bird’seye view of the utilization of recycled solid wastes in road engineering,highlighting advances,benefits,challenges,and future prospects.展开更多
Deeply subducted lithospheric slabs may reach to the mantle transition zone(MTZ,410-660 km depth)or even to the core–mantle boundary(CMB)at depths of^2900km.Our knowledge of the fate of subducted surface material at ...Deeply subducted lithospheric slabs may reach to the mantle transition zone(MTZ,410-660 km depth)or even to the core–mantle boundary(CMB)at depths of^2900km.Our knowledge of the fate of subducted surface material at the MTZ or near the CMB is poor and based mainly on the tomography data and laboratory experiments through indirect methods.Limited data come from the samples of deep mantle diamonds and their mineral inclusions obtained from kimberlites and associated rock assemblages in old cratons.We report in this presentation new data and observations from diamonds and other UHP minerals recovered from ophiolites that we consider as a new window into the life cycle of deeply subducted oceanic and continental crust.Ophiolites are fragments of ancient oceanic lithosphere tectonically accreted into continental margins,and many contain significant podiform chromitites.Our research team has investigated over the last 10 years ultrahigh-pressure and super-reducing mineral groups discovered in peridotites and/or chromitites of ophiolites around the world,including the Luobusa(Tibet),Ray-Iz(Polar Urals-Russia),and 12 other ophiolites from 8orogenic belts in 5 different countries(Albania,China,Myanmar,Russia,and Turkey).High-pressure minerals include diamond,coesite,pseudomorphic stishovite,qingsongite(BN)and Ca-Si perovskite,and the most important native and highly reduced minerals recovered to date include moissanite(Si C),Ni-Mn-Co alloys,Fe-Si and Fe-C phases.These mineral groups collectively confirm extremely high?pressures(300 km to≥660 km)and super-reducing conditions in their environment of formation in the mantle.All of the analyzed diamonds have unusually light carbon isotope compositions(δ13C=-28.7 to-18.3‰)and variable trace element contents that*d i stinguish them from most kimberlitic and UHPmetamorphic varieties.The presence of exsolution lamellae of diopside and coesite in some chromite grains suggests chromite crystallization depths around>380 km,near the mantle transition zone.The carbon isotopes and other features of the high-pressure and super-reduced mineral groups point to previously subducted surface material as their source of origin.Recycling of subducted crust in the deep mantle may proceed in three stages:Stage 1–Carbon-bearing fluids and melts may have been formed in the MTZ,in the lower mantle or even near the CMB.Stage 2–Fluids or melts may rise along with deep plumes through the lower mantle and reach the MTZ.Some minerals,such as diamond,stishovite,qingsongite and Ca-silicate perovskite can precipitate from these fluids or melts in the lower mantle during their ascent.Material transported to the MTZ would be mixed with highly reduced and UHP phases,presumably derived from zones with extremely low f O2,as required for the formation of moissanite and other native elements.Stage 3–Continued ascent above the transition of peridotites containing chromite and ultrahigh-pressure minerals transports them to shallow mantle depths,where they participate in decompressional partial melting and oceanic lithosphere formation.The widespread occurrence of ophiolite-hosted diamonds and associated UHP mineral groups suggests that they may be a common feature of in-situ oceanic mantle.Because mid-ocean ridge spreading environments are plate boundaries widely distributed around the globe,and because the magmatic accretion of oceanic plates occurs mainly along these ridges,the on-land remnants of ancient oceanic lithosphere produced at former mid-ocean ridges provide an important window into the Earth’s recycling system and a great opportunity to probe the nature of deeply recycled crustal material residing in the deep mantle展开更多
The industrial system should learn from the natural ecosystem. The resource utilization efficiency should be increased and the environmental load should be decreased, depending on the materials recycled in the system....The industrial system should learn from the natural ecosystem. The resource utilization efficiency should be increased and the environmental load should be decreased, depending on the materials recycled in the system. The classification of industrial materials from the viewpoint of large-scale recycling was stated. Recycling of materials, on three different levels, was introduced in the industrial system. The metal flow diagram in the life cycle of products, in the case of no materials recycled, materials partially recycled, and materials completely recycled, was given. The natural resource conservation and the waste emission reduction were analyzed under the condition of materials completely recycled. The expressions for the relation between resource efficiency and material recycling rate, and the relation between eco-efficiency and material recycling rate were derived, and the curves describing the relationship between them were protracted. The diagram of iron flow in the life cycle of iron and steel products in China, in 2001, was given, and the iron resource efficiency, material recycling rate, and iron eco-efficiency were analyzed. The variation of iron resource efficiency with the material recycling rate was analyzed for two different production ratios.展开更多
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-...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.展开更多
Currently,the gradual depletion of fossil resources and the large amount of plastic waste are causing serious harm to the land and marine ecology.The rapid development of wearable smart fibers is accompanied by rapid ...Currently,the gradual depletion of fossil resources and the large amount of plastic waste are causing serious harm to the land and marine ecology.The rapid development of wearable smart fibers is accompanied by rapid growth in the material demand for fibers,and the development of green and high-performance biomass-based fibers has become an important research topic to reduce the dependence on synthetic fiber materials and the harm to the environment.Here,chitosan is first prepared from the waste material by chemical methods.Then the chitosan-based self-powered induction fibers are prepared by electrospinning core wire technique.Chitosan-based self-powered sensing fiber is ultra-light and flexible,which can achieve about 2500 collisions without damaging the surface.Chitosan-based self-powered sensing fiber can also be used in smart home sensing applications to control home appliance switches with a light touch,which has a great application prospect in smart home and wearable fields.展开更多
Alkaline zinc manganese dioxide(Zn–MnO2)batteries are widely used in everyday life. Recycling of waste alkaline Zn–MnO2 batteries has always been a hot environmental concern. In this study, a simple and costeffect...Alkaline zinc manganese dioxide(Zn–MnO2)batteries are widely used in everyday life. Recycling of waste alkaline Zn–MnO2 batteries has always been a hot environmental concern. In this study, a simple and costeffective process for synthesizing Mn3O4/carbon nanotube(CNT) nanocomposites from recycled alkaline Zn–MnO2 batteries is presented. Manganese oxide was recovered from spent Zn–MnO2 battery cathodes. The Mn3O4/CNT nanocomposites were produced by ball milling the recovered manganese oxide in a commercial multi-wall carbon nanotubes(MWCNTs) solution. Scanning electron microscopy(SEM) analysis demonstrates that the nanocomposite has a unique three-dimensional(3D) bird nest structure. Mn3O4 nanoparticles are homogeneously distributed on MWCNT framework. Mn3O4/CNT nanocomposites were evaluated as an anode material for lithium-ion batteries, exhibiting a highly reversible specific capacitance of -580 mA h·g^-1 after 100 cycles. Moreover, Mn3O4/CNT nanocomposite also shows a fairly positive onset potential of -0.15 V and quite high oxygen reducibility when considered as an electrocatalyst for oxygen reduction reaction.展开更多
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 ...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.展开更多
With the rapid development of electronic equipment and communication technology,the demand for polymer composites with high thermal conductivity and mechanical properties has increased significantly.However,its nondeg...With the rapid development of electronic equipment and communication technology,the demand for polymer composites with high thermal conductivity and mechanical properties has increased significantly.However,its nondegradable polymer matrix will inevitably bring more and more serious environmental pollution.Therefore,it is urgent to develop biodegradable thermally conductive polymer composites.In this work,biodegradable poly(butylene adipate-coterephthalate)(PBAT)is used as the matrix material,and vacuum-assisted filtration technology is employed to prepare carbon nanotube(CNT)and cellulose nanocrystal(CNC)networks with high thermal conductivity.Then CNT-CNC/PBAT composites with high thermal conductivity and excellent mechanical properties are prepared by the ultrasonic-assisted forced infiltration method.Both experiment and simulation methods are used to systematically investigate the thermally conductive and dissipation performances of the CNT-CNC/PBAT composites.Above all,a simple alcoholysis reaction is applied to realize the separation of the PBAT matrix and functional fillers without destroying the conductive network skeleton,which makes it possible for the recycling of thermally conductive polymer composites.展开更多
It is a long-term pursuit,and also,a challenge to significantly improve the mechanical strength of thermoplastic polymers using readily dispersed polymers as nanofillers.In this study,we demonstrated that in situ form...It is a long-term pursuit,and also,a challenge to significantly improve the mechanical strength of thermoplastic polymers using readily dispersed polymers as nanofillers.In this study,we demonstrated that in situ formed carboxylic acid-functionalized poly(aryl ether sulfone)(PAES-COOH)/polyvinylpyrrolidone(PVPON)complex nanoparticles can significantly enhance the mechanical strength of PAES-COOH by mixing PAES-COOH with a small fraction of PVPON.The PAES-COOH/PVPON10%composite,which contained∼10 wt%PVPON,exhibited a tensile strength of∼104.8 MPa and Young’s modulus of∼932.2 MPa,which were∼2.0 and∼1.7 times higher than those of the PAES-COOH,respectively.The PAES-COOH/PVPON nanoparticles which were uniformly dispersed in PAES-COOH matrices and had strong hydrogen-bonding interactions with PAES-COOH,served as nanofillers to reinforce the mechanical strength of the PAES-COOH.The PAES-COOH/PVPON_(10%)composites possessed excellent solvent-assisted healability,and the fractured composites could be healed to restore their original mechanical strength.Meanwhile,the PAES-COOH/PVPON_(10%)composites could be recycled multiple times,and yet retained their shape integration and their original mechanical strength.展开更多
基金supported by the National Natural Science Foundation of China(No.51274075)the National Environmental Technology Special Project(No.201009028)Guangdong Province-department University-industry Collaboration Project(Grant No.2012B091100315)
文摘With the rapid development of consumer electronics and electric vehicles(EV), a large number of spent lithium-ion batteries(LIBs) have been generated worldwide. Thus, effective recycling technologies to recapture a significant amount of valuable metals contained in spent LIBs are highly desirable to prevent the environmental pollution and resource depletion. In this work, a novel recycling technology to regenerate a LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 cathode material from spent LIBs with different cathode chemistries has been developed. By dismantling, crushing,leaching and impurity removing, the LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2(selected as an example of LiNi_xCo_yMn_(1-x-y)O_2) powder can be directly prepared from the purified leaching solution via co-precipitation followed by solid-state synthesis. For comparison purposes, a fresh-synthesized sample with the same composition has also been prepared using the commercial raw materials via the same method. X-ray diffraction(XRD), scanning electron microscopy(SEM) and electrochemical measurements have been carried out to characterize these samples. The electrochemical test result suggests that the re-synthesized sample delivers cycle performance and low rate capability which are comparable to those of the freshsynthesized sample. This novel recycling technique can be of great value to the regeneration of a pure and marketable LiNi_xCo_yMn_(1-x-y)O_2 cathode material with low secondary pollution.
基金Support by the National Natural Science Foundation of China(No.92258303)the Project of Donghai Laboratory(No.DH-2022ZY0005)。
文摘The deep structure,material circulation,and dynamic processes in the Southeast Asia have long been an elusive scientific puzzle due to the lack of systematic scientific observations and recognized theoretical models.Based on the deep seismic tomography using long-period natural earthquake data,in this study,the deep structure and material circulation of the curved subduction system in Southeast Asia was studied,and the dynamic processes since 100 million years ago was reconstructed.It is pointed out that challenges still exist in the precise reconstruction of deep mantle structures of the study area,the influence of multi-stage subduction on deep material exchange and shallow magma activity,as well as the spatiotemporal evolution and coupling mechanism of multi-plate convergence.Future work should focus on high-resolution land-sea joint 3-D seismic tomography imaging of the curved subduction system in the Southeast Asia,combined with geochemical analysis and geodynamic modelling works.
基金A number of financial funding including the National Natural Science Foundation of China(Nos.52278455,52268068,52078018,52208434)National Key R&D Program of China(2022YFE0137300)+5 种基金the ShuGuang Program of Shanghai Education Development Foundation and Shanghai Municipal Education Commission(No.21SG24)China Postdoctoral Science Foundation(No.2022M711079)Provincial Natural Science Foundation/Postdoctoral Research Grant/Science and Technology Project(Nos.222300420142,202103107,192102310229)have to be acknowledged for supporting this manuscript.As well,some university's funding including Chang'an University(No.CHD300102213507)Changsha University of Science and Technology(No.KFJ230206)Henan University of Technology(No.21420156)are also appreciated.Meanwhile,the strong supports from the Editor Office of Journal of Road Engineering have to be highly acknowledged for their kindly inviting,guiding,assisting,and improving on the manuscript of current review.
文摘Recent trends in road engineering have explored the potential of incorporating recycled solid wastes into infrastructures that including pavements,bridges,tunnels,and accessory structures.The utilization of solid wastes is expected to offer sustainable solutions to waste recycling while enhancing the performance of roads.This review provides an extensive analysis of the recycling of three main types of solid wastes for road engineering purposes:industrial solid waste,infrastructure solid waste,and municipal life solid waste.Industrial solid wastes suitable for road engineering generally include coal gangue,fly ash,blast furnace slag,silica fume,and steel slag,etc.Infrastructure solid wastes recycled in road engineering primarily consist of construction&demolition waste,reclaimed asphalt pavements,and recycled cement concrete.Furthermore,recent exploration has extended to the utilization of municipal life solid wastes,such as incinerated bottom ash,glass waste,electronics waste,plastic waste,and rubber waste in road engineering applications.These recycled solid wastes are categorized into solid waste aggregates,solid waste cements,and solid waste fillers,each playing distinct roles in road infrastructure.Roles of solid waste acting aggregates,cements,and fillers in road infrastructures were fully investigated,including their pozzolanic properties,integration effects to virgin materials,modification or enhancement solutions,engineering performances.Utilization of these materials not only addresses the challenge of waste management but also offers environmental benefits aiming carbon neutral and contributes to sustainable infrastructure development.However,challenges such as variability in material properties,environmental impact mitigation,secondary pollution to environment by leaching,and concerns regarding long-term performance need to be further addressed.Despite these challenges,the recycled solid wastes hold immense potential in revolutionizing road construction practices and fostering environmental stewardship.This review delves into a bird’seye view of the utilization of recycled solid wastes in road engineering,highlighting advances,benefits,challenges,and future prospects.
文摘Deeply subducted lithospheric slabs may reach to the mantle transition zone(MTZ,410-660 km depth)or even to the core–mantle boundary(CMB)at depths of^2900km.Our knowledge of the fate of subducted surface material at the MTZ or near the CMB is poor and based mainly on the tomography data and laboratory experiments through indirect methods.Limited data come from the samples of deep mantle diamonds and their mineral inclusions obtained from kimberlites and associated rock assemblages in old cratons.We report in this presentation new data and observations from diamonds and other UHP minerals recovered from ophiolites that we consider as a new window into the life cycle of deeply subducted oceanic and continental crust.Ophiolites are fragments of ancient oceanic lithosphere tectonically accreted into continental margins,and many contain significant podiform chromitites.Our research team has investigated over the last 10 years ultrahigh-pressure and super-reducing mineral groups discovered in peridotites and/or chromitites of ophiolites around the world,including the Luobusa(Tibet),Ray-Iz(Polar Urals-Russia),and 12 other ophiolites from 8orogenic belts in 5 different countries(Albania,China,Myanmar,Russia,and Turkey).High-pressure minerals include diamond,coesite,pseudomorphic stishovite,qingsongite(BN)and Ca-Si perovskite,and the most important native and highly reduced minerals recovered to date include moissanite(Si C),Ni-Mn-Co alloys,Fe-Si and Fe-C phases.These mineral groups collectively confirm extremely high?pressures(300 km to≥660 km)and super-reducing conditions in their environment of formation in the mantle.All of the analyzed diamonds have unusually light carbon isotope compositions(δ13C=-28.7 to-18.3‰)and variable trace element contents that*d i stinguish them from most kimberlitic and UHPmetamorphic varieties.The presence of exsolution lamellae of diopside and coesite in some chromite grains suggests chromite crystallization depths around>380 km,near the mantle transition zone.The carbon isotopes and other features of the high-pressure and super-reduced mineral groups point to previously subducted surface material as their source of origin.Recycling of subducted crust in the deep mantle may proceed in three stages:Stage 1–Carbon-bearing fluids and melts may have been formed in the MTZ,in the lower mantle or even near the CMB.Stage 2–Fluids or melts may rise along with deep plumes through the lower mantle and reach the MTZ.Some minerals,such as diamond,stishovite,qingsongite and Ca-silicate perovskite can precipitate from these fluids or melts in the lower mantle during their ascent.Material transported to the MTZ would be mixed with highly reduced and UHP phases,presumably derived from zones with extremely low f O2,as required for the formation of moissanite and other native elements.Stage 3–Continued ascent above the transition of peridotites containing chromite and ultrahigh-pressure minerals transports them to shallow mantle depths,where they participate in decompressional partial melting and oceanic lithosphere formation.The widespread occurrence of ophiolite-hosted diamonds and associated UHP mineral groups suggests that they may be a common feature of in-situ oceanic mantle.Because mid-ocean ridge spreading environments are plate boundaries widely distributed around the globe,and because the magmatic accretion of oceanic plates occurs mainly along these ridges,the on-land remnants of ancient oceanic lithosphere produced at former mid-ocean ridges provide an important window into the Earth’s recycling system and a great opportunity to probe the nature of deeply recycled crustal material residing in the deep mantle
基金National Key Fundamental Research and Development Project of China (2005CB724206) National NaturalScience Foundation of China (50334020)
文摘The industrial system should learn from the natural ecosystem. The resource utilization efficiency should be increased and the environmental load should be decreased, depending on the materials recycled in the system. The classification of industrial materials from the viewpoint of large-scale recycling was stated. Recycling of materials, on three different levels, was introduced in the industrial system. The metal flow diagram in the life cycle of products, in the case of no materials recycled, materials partially recycled, and materials completely recycled, was given. The natural resource conservation and the waste emission reduction were analyzed under the condition of materials completely recycled. The expressions for the relation between resource efficiency and material recycling rate, and the relation between eco-efficiency and material recycling rate were derived, and the curves describing the relationship between them were protracted. The diagram of iron flow in the life cycle of iron and steel products in China, in 2001, was given, and the iron resource efficiency, material recycling rate, and iron eco-efficiency were analyzed. The variation of iron resource efficiency with the material recycling rate was analyzed for two different production ratios.
文摘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.
基金The authors are grateful for the support received from National Natural Science Foundation of China(Grant No.22109012)Natural Science Foundation of the Beijing Municipality(Grant No.2212052)the Fundamental Research Funds for the Central Universities(Grant No.E1E46805).
文摘Currently,the gradual depletion of fossil resources and the large amount of plastic waste are causing serious harm to the land and marine ecology.The rapid development of wearable smart fibers is accompanied by rapid growth in the material demand for fibers,and the development of green and high-performance biomass-based fibers has become an important research topic to reduce the dependence on synthetic fiber materials and the harm to the environment.Here,chitosan is first prepared from the waste material by chemical methods.Then the chitosan-based self-powered induction fibers are prepared by electrospinning core wire technique.Chitosan-based self-powered sensing fiber is ultra-light and flexible,which can achieve about 2500 collisions without damaging the surface.Chitosan-based self-powered sensing fiber can also be used in smart home sensing applications to control home appliance switches with a light touch,which has a great application prospect in smart home and wearable fields.
基金financially supported by the National Natural Science Foundation of China(Nos.21671096 and 21603094)the Shenzhen Peacock Plan(No.KQCX2014052215 0815065)+1 种基金the Natural Science Foundation of Shenzhen(Nos.JCYJ20150630145302231 and JCYJ20150331101823677)the Science and Technology Innovation Foundation for the Undergraduates of South University of Science and Technology of China(Nos.2016S10,2016S20,2015x19 and 2015x12)
文摘Alkaline zinc manganese dioxide(Zn–MnO2)batteries are widely used in everyday life. Recycling of waste alkaline Zn–MnO2 batteries has always been a hot environmental concern. In this study, a simple and costeffective process for synthesizing Mn3O4/carbon nanotube(CNT) nanocomposites from recycled alkaline Zn–MnO2 batteries is presented. Manganese oxide was recovered from spent Zn–MnO2 battery cathodes. The Mn3O4/CNT nanocomposites were produced by ball milling the recovered manganese oxide in a commercial multi-wall carbon nanotubes(MWCNTs) solution. Scanning electron microscopy(SEM) analysis demonstrates that the nanocomposite has a unique three-dimensional(3D) bird nest structure. Mn3O4 nanoparticles are homogeneously distributed on MWCNT framework. Mn3O4/CNT nanocomposites were evaluated as an anode material for lithium-ion batteries, exhibiting a highly reversible specific capacitance of -580 mA h·g^-1 after 100 cycles. Moreover, Mn3O4/CNT nanocomposite also shows a fairly positive onset potential of -0.15 V and quite high oxygen reducibility when considered as an electrocatalyst for oxygen reduction reaction.
文摘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.
基金Basic Science Center Program,Grant/Award Number:51988102National Natural Science Foundation of China,Grant/Award Numbers:52003019,52073011+1 种基金National Natural Science Foundation of China,Sinopec Key Projects,Grant/Award Number:420043-6Talents Introduction Project in Beijing University of Chemical Technology,Grant/Award Number:buctrc201909。
文摘With the rapid development of electronic equipment and communication technology,the demand for polymer composites with high thermal conductivity and mechanical properties has increased significantly.However,its nondegradable polymer matrix will inevitably bring more and more serious environmental pollution.Therefore,it is urgent to develop biodegradable thermally conductive polymer composites.In this work,biodegradable poly(butylene adipate-coterephthalate)(PBAT)is used as the matrix material,and vacuum-assisted filtration technology is employed to prepare carbon nanotube(CNT)and cellulose nanocrystal(CNC)networks with high thermal conductivity.Then CNT-CNC/PBAT composites with high thermal conductivity and excellent mechanical properties are prepared by the ultrasonic-assisted forced infiltration method.Both experiment and simulation methods are used to systematically investigate the thermally conductive and dissipation performances of the CNT-CNC/PBAT composites.Above all,a simple alcoholysis reaction is applied to realize the separation of the PBAT matrix and functional fillers without destroying the conductive network skeleton,which makes it possible for the recycling of thermally conductive polymer composites.
基金This work was supported by the National Natural Science Foundation of China(NSFC grant 20935004 and 21774049).
文摘It is a long-term pursuit,and also,a challenge to significantly improve the mechanical strength of thermoplastic polymers using readily dispersed polymers as nanofillers.In this study,we demonstrated that in situ formed carboxylic acid-functionalized poly(aryl ether sulfone)(PAES-COOH)/polyvinylpyrrolidone(PVPON)complex nanoparticles can significantly enhance the mechanical strength of PAES-COOH by mixing PAES-COOH with a small fraction of PVPON.The PAES-COOH/PVPON10%composite,which contained∼10 wt%PVPON,exhibited a tensile strength of∼104.8 MPa and Young’s modulus of∼932.2 MPa,which were∼2.0 and∼1.7 times higher than those of the PAES-COOH,respectively.The PAES-COOH/PVPON nanoparticles which were uniformly dispersed in PAES-COOH matrices and had strong hydrogen-bonding interactions with PAES-COOH,served as nanofillers to reinforce the mechanical strength of the PAES-COOH.The PAES-COOH/PVPON_(10%)composites possessed excellent solvent-assisted healability,and the fractured composites could be healed to restore their original mechanical strength.Meanwhile,the PAES-COOH/PVPON_(10%)composites could be recycled multiple times,and yet retained their shape integration and their original mechanical strength.