With the application of resins in various fields, numerous waste resins that are difficult to treat have been produced. The industrial wastewater containing Cr(Ⅵ) has severely polluted soil and groundwater environmen...With the application of resins in various fields, numerous waste resins that are difficult to treat have been produced. The industrial wastewater containing Cr(Ⅵ) has severely polluted soil and groundwater environments, thereby endangering human health. Therefore, in this paper, a novel functionalized mesoporous adsorbent PPR-Z was synthesized from waste amidoxime resin for adsorbing Cr(Ⅵ). The waste amidoxime resin was first modified with H3PO4 and ZnCl_(2), and subsequently, it was carbonized through slow thermal decomposition. The static adsorption of PPR-Z conforms to the pseudo-second-order kinetic model and Langmuir isotherm, indicating that the Cr(Ⅵ) adsorption by PPR-Z is mostly chemical adsorption and exhibits single-layer adsorption. The saturated adsorption capacity of the adsorbent for Cr(Ⅵ) could reach 255.86 mg/g. The adsorbent could effectively reduce Cr(Ⅵ) to Cr(Ⅲ) and decrease the toxicity of Cr(Ⅵ) during adsorption. PPR-Z exhibited Cr(Ⅵ) selectivity in electroplating wastewater. The main mechanisms involved in the Cr(Ⅵ) adsorption are the chemical reduction of Cr(Ⅵ) into Cr(Ⅲ) and electrostatic and coordination interactions. Preparation of PPR-Z not only solves the problem of waste resin treatment but also effectively controls Cr(Ⅵ) pollution and realizes the concept of “treating waste with waste”.展开更多
To effectively separate and recover Co(Ⅱ) from the leachate of spent lithium-ion battery cathodes,we investigated solvent extraction with quaternary ammonium salt N263 in the sodium nitrite system.NO_(2)^(-)combines ...To effectively separate and recover Co(Ⅱ) from the leachate of spent lithium-ion battery cathodes,we investigated solvent extraction with quaternary ammonium salt N263 in the sodium nitrite system.NO_(2)^(-)combines with Co(Ⅱ) to form an anion [Co(NO_(2))_(3)]^(-),and it is then extracted by N263.The extraction of Co(Ⅱ) is related to the concentration of NO_(2)^(-).The extraction efficiency of Co(Ⅱ) reaches the maximum of99.16%,while the extraction efficiencies of Ni(Ⅱ),Mn(Ⅱ),and Li(Ⅰ) are 9.27%-9.80% under the following conditions:30vol% of N263 and15vol% of iso-propyl alcohol in sulfonated kerosene,the volume ratio of the aqueous-to-organic phase is 2:1,the extraction time is 30 min,and1 M sodium nitrite in 0.1 MHNO_(3).The theoretical stages require for the Co(Ⅱ) extraction are performed in the McCabe–Thiele diagram,and the extraction efficiency of Co(Ⅱ) reaches more than 99.00% after three-stage counter-current extraction with Co(Ⅱ) concentration of 2544mg/L.When the HCl concentration is 1.5 M,the volume ratio of the aqueous-to-organic phase is 1:1,the back-extraction efficiency of Co(Ⅱ)achieves 91.41%.After five extraction and back-extraction cycles,the Co(Ⅱ) extraction efficiency can still reach 93.89%.The Co(Ⅱ) extraction efficiency in the actual leaching solution reaches 100%.展开更多
为从高放射废液(HLLW)中回收钯和银,采用循环伏安法和恒电位沉积法研究钯和银在模拟硝酸溶液中的电化学行为。利用扫描电子显微镜(SEM)和X射线衍射仪(XRD)观察沉积产物的形貌并分析其组成。结果表明,在单独电沉积银时亚硝酸根的生成促...为从高放射废液(HLLW)中回收钯和银,采用循环伏安法和恒电位沉积法研究钯和银在模拟硝酸溶液中的电化学行为。利用扫描电子显微镜(SEM)和X射线衍射仪(XRD)观察沉积产物的形貌并分析其组成。结果表明,在单独电沉积银时亚硝酸根的生成促进银的溶解。当同时电沉积钯和银时,相同时间内更多金属被沉积,且沉积的银没有再出现溶解。在-0.4~-0.6 V (vs MSE)的电位下,溶液中的金属被完全电沉积回收,沉积物组成为银和氢化钯。钯的电沉积可以促进析氢,随后加速亚硝酸根和氢气之间的反应,使溶液中的亚硝酸浓度降低,从而抑制银的再溶解。展开更多
The demand for Li-ion batteries (LIBs) for vehicles is increasing. However, LIBs use valuable rare metals, such as Co and Li, aswell as environmentally toxic reagents. LIBs are also necessary to utilize for a long per...The demand for Li-ion batteries (LIBs) for vehicles is increasing. However, LIBs use valuable rare metals, such as Co and Li, aswell as environmentally toxic reagents. LIBs are also necessary to utilize for a long period and to recycle useful materials. The reduction, reuse,and recycle (3R) of spent LIBs is an important consideration in constructing a circular economy. In this paper, a flowsheet of the 3R of LIBs isproposed and methods to reduce the utilization of valuable rare metals and the amount of spent LIBs by remanufacturing used parts and designingnew batteries considering the concept of 3R are described. Next, several technological processes for the reuse and recycling of LIBs are introduced.These technologies include discharge, sorting, crushing, binder removal, physical separation, and pyrometallurgical and hydrometallurgicalprocessing. Each process, as well as the related physical, chemical, and biological treatments, are discussed. Finally, the problem of developedtechnologies and future subjects for 3R of LIBs are described.展开更多
This paper presents the basic principles of three different types of separating methods and a general guideline for choosing the most effective method for sorting plastic mixtures. It also presents the results of the ...This paper presents the basic principles of three different types of separating methods and a general guideline for choosing the most effective method for sorting plastic mixtures. It also presents the results of the tests carried out for separation of PVC, ABS and PET from different kinds of plastic mixtures in order to improve the grade of the raw input used in mechanical or feedstock recycling.展开更多
Generally speaking,anionic metal concentrations in wastewater from industries and mineral processing plants are well above the allowed limits for effluent set by the Ministry of Environment of Japan. Nowadays,the remo...Generally speaking,anionic metal concentrations in wastewater from industries and mineral processing plants are well above the allowed limits for effluent set by the Ministry of Environment of Japan. Nowadays,the removal of anionic ions has been considered difficult and development of new process is desperately needed. In this paper,we report the development of three hydroxide-type adsorbents,illustrating their adsorption efficiency in removing As,Se,Mo and Sb ions from aqueous solutions. The main finding of this work was that the adsorption behavior was influenced very much by both the pH and the adsorbent concentration. Nevertheless,the newly developed hydroxide-type adsorbents were very effective in reducing the concentration of those anionic ions.展开更多
A series of single-phase double perovskite Pr1-xGdxBaCo_(2)-yFeyO_(5+σ)(x=0,0.5 and 1,0≤y≤1)materials were engineered through A/B site co-doping strategy to improve the mechanical,electrical and electrochemical pro...A series of single-phase double perovskite Pr1-xGdxBaCo_(2)-yFeyO_(5+σ)(x=0,0.5 and 1,0≤y≤1)materials were engineered through A/B site co-doping strategy to improve the mechanical,electrical and electrochemical properties as potential cathode materials for the application of intermediate solid oxide fuel cells(IT-SOFCs).The corresponding thermochemical stability,thermal expansion behavior,electrical conductivity and cathodic polarization resistance of the materials were systematically investigated.It was found that the A-site dual lanthanide doped Pr_(0.5)Gd_(0.5)BaCo_(2)O_(5+σ)(PGBCO)exhibits improved electrical conductivity,reduced thermal expansion,and comparatively low electrochemical polarization resistance versus single lanthanide double perovskite,PrBaCo_(2)O_(5+σ)(PBCO)and GdBaCo_(2)O_(5+σ)(GBCO)materials.Further investigation on the effect of B-site Fe-doping on Pr_(0.5)Gd_(0.5)BaCo_(2)-yFeyO_(5)+σ(PGBCF-y,0≤y≤1)reveals that all the PGBCF-y compositions exhibit excellent chemical stability with Gd-doped ceria(GDC)at operating temperatures not higher than 1100℃.Besides,doping of Fe in B-site can effectively reduce the thermal expansion coefficients(TECs)of the Pr_(0.5)Gd_(0.5)BaCo_(2)O_(5)+σceramics at 30e1000℃.And the electrochemical impedance spectra(EIS)results show that the PGBCF-y|GDC|PGBCF-y symmetric cells have acceptable low area specific polarization resistances.Further examination of the cathodic polarization and characteristic capacitance from the AC impedance spectra by employing the relaxation time distribution(DRT)method demonstrated that charge transfer is the dominating subprocess for the oxygen transport through the materials.展开更多
Carbon dioxide（CO2） emissions are a leading contributor to the negative effects of global warming. Globally, research has focused on effective means of reducing and mitigating CO2 emissions. In this study, we examin...Carbon dioxide（CO2） emissions are a leading contributor to the negative effects of global warming. Globally, research has focused on effective means of reducing and mitigating CO2 emissions. In this study, we examined the efficacy of eco-industrial parks（EIPs） and accelerated mineral carbonation techniques in reducing CO2 emissions in South Korea.First, we used Logarithmic Mean Divisia Index（LMDI） analysis to determine the trends in carbon production and mitigation at the existing EIPs. We found that, although CO2 was generated as byproducts and wastes of production at these EIPs, improved energy intensity effects occurred at all EIPs, and we strongly believe that EIPs are a strong alternative to traditional industrial complexes for reducing net carbon emissions. We also examined the optimal conditions for using accelerated mineral carbonation to dispose of hazardous fly ash produced through the incineration of municipal solid wastes at these EIPs. We determined that this technique most efficiently sequestered CO2 when micro-bubbling, low flow rate inlet gas, and ammonia additives were employed.展开更多
Photocatalytic uranium extraction from radioactive nuclear wastewater and seawater is critical for promoting the sustainable advancement of nuclear industry,but the complexity of real-world environments,particularly t...Photocatalytic uranium extraction from radioactive nuclear wastewater and seawater is critical for promoting the sustainable advancement of nuclear industry,but the complexity of real-world environments,particularly the occurrence of anoxic and oxygen-enriched states,presents significant challenges to effective uranium extraction.Here,a layered hollow core–shell structure of Bi_(2)O_(3)/g-C_(3)N_(4)Z-scheme heterojunction photocatalyst has been designed and successfully applied for photocatalytic uranium extraction in both aerobic and oxygen-free conditions,and the extraction efficiency of uranium can reach 98.4%and 99.0%,respectively.Moreover,the photocatalyst still has ultra-high extraction efficiency under the influence of pH,inorganic ions,and other factors.The exceptional capability for uranium extraction is on the one hand due to the distinctive hollow core–shell architecture,which furnishes an abundant quantity of active sites.On the other hand,benefiting from the suitable band gap structure brought by the construction of Z-scheme heterojunction,Bi_(2)O_(3)/g-C_(3)N_(4)exhibits current densities(1.00μA/cm^(2))that are 5.26 and 3.85 times greater than Bi_(2)O_(3)and g-C_(3)N_(4),respectively,and the directional migration mode of Z-scheme carriers significantly prolongs the lifetime of photogenerated charges(1.53 ns),which separately surpass the pure samples by factors of 5.10 and 3.19.Furthermore,the reaction mechanism and reaction process of photocatalytic uranium extraction are investigated in the presence and absence of oxygen,respectively.展开更多
基金supported by the National Natural Science Foundation of China (No.52364022)the Natural Science Foundation of Guangxi Province,China (Nos.2023JJA160192 and 2021GXNSFAA220096)+1 种基金the Guangxi Science and Technology Major Project,China (No.AA23073018)the Guangxi Chongzuo Science and Technology Plan,China (No.2023ZY00503).
文摘With the application of resins in various fields, numerous waste resins that are difficult to treat have been produced. The industrial wastewater containing Cr(Ⅵ) has severely polluted soil and groundwater environments, thereby endangering human health. Therefore, in this paper, a novel functionalized mesoporous adsorbent PPR-Z was synthesized from waste amidoxime resin for adsorbing Cr(Ⅵ). The waste amidoxime resin was first modified with H3PO4 and ZnCl_(2), and subsequently, it was carbonized through slow thermal decomposition. The static adsorption of PPR-Z conforms to the pseudo-second-order kinetic model and Langmuir isotherm, indicating that the Cr(Ⅵ) adsorption by PPR-Z is mostly chemical adsorption and exhibits single-layer adsorption. The saturated adsorption capacity of the adsorbent for Cr(Ⅵ) could reach 255.86 mg/g. The adsorbent could effectively reduce Cr(Ⅵ) to Cr(Ⅲ) and decrease the toxicity of Cr(Ⅵ) during adsorption. PPR-Z exhibited Cr(Ⅵ) selectivity in electroplating wastewater. The main mechanisms involved in the Cr(Ⅵ) adsorption are the chemical reduction of Cr(Ⅵ) into Cr(Ⅲ) and electrostatic and coordination interactions. Preparation of PPR-Z not only solves the problem of waste resin treatment but also effectively controls Cr(Ⅵ) pollution and realizes the concept of “treating waste with waste”.
基金financially supported by the National Natural Science Foundation of China(No.51804084)the Natural Science Foundation of Guangxi Province,China(No.2021GXNSFAA220096)the Science and Technology Major Project of Guangxi Province,China(No.AA17204100)。
文摘To effectively separate and recover Co(Ⅱ) from the leachate of spent lithium-ion battery cathodes,we investigated solvent extraction with quaternary ammonium salt N263 in the sodium nitrite system.NO_(2)^(-)combines with Co(Ⅱ) to form an anion [Co(NO_(2))_(3)]^(-),and it is then extracted by N263.The extraction of Co(Ⅱ) is related to the concentration of NO_(2)^(-).The extraction efficiency of Co(Ⅱ) reaches the maximum of99.16%,while the extraction efficiencies of Ni(Ⅱ),Mn(Ⅱ),and Li(Ⅰ) are 9.27%-9.80% under the following conditions:30vol% of N263 and15vol% of iso-propyl alcohol in sulfonated kerosene,the volume ratio of the aqueous-to-organic phase is 2:1,the extraction time is 30 min,and1 M sodium nitrite in 0.1 MHNO_(3).The theoretical stages require for the Co(Ⅱ) extraction are performed in the McCabe–Thiele diagram,and the extraction efficiency of Co(Ⅱ) reaches more than 99.00% after three-stage counter-current extraction with Co(Ⅱ) concentration of 2544mg/L.When the HCl concentration is 1.5 M,the volume ratio of the aqueous-to-organic phase is 1:1,the back-extraction efficiency of Co(Ⅱ)achieves 91.41%.After five extraction and back-extraction cycles,the Co(Ⅱ) extraction efficiency can still reach 93.89%.The Co(Ⅱ) extraction efficiency in the actual leaching solution reaches 100%.
基金the financial supports from the National Natural Science Foundation of China (No. 11975082)。
文摘为从高放射废液(HLLW)中回收钯和银,采用循环伏安法和恒电位沉积法研究钯和银在模拟硝酸溶液中的电化学行为。利用扫描电子显微镜(SEM)和X射线衍射仪(XRD)观察沉积产物的形貌并分析其组成。结果表明,在单独电沉积银时亚硝酸根的生成促进银的溶解。当同时电沉积钯和银时,相同时间内更多金属被沉积,且沉积的银没有再出现溶解。在-0.4~-0.6 V (vs MSE)的电位下,溶液中的金属被完全电沉积回收,沉积物组成为银和氢化钯。钯的电沉积可以促进析氢,随后加速亚硝酸根和氢气之间的反应,使溶液中的亚硝酸浓度降低,从而抑制银的再溶解。
文摘The demand for Li-ion batteries (LIBs) for vehicles is increasing. However, LIBs use valuable rare metals, such as Co and Li, aswell as environmentally toxic reagents. LIBs are also necessary to utilize for a long period and to recycle useful materials. The reduction, reuse,and recycle (3R) of spent LIBs is an important consideration in constructing a circular economy. In this paper, a flowsheet of the 3R of LIBs isproposed and methods to reduce the utilization of valuable rare metals and the amount of spent LIBs by remanufacturing used parts and designingnew batteries considering the concept of 3R are described. Next, several technological processes for the reuse and recycling of LIBs are introduced.These technologies include discharge, sorting, crushing, binder removal, physical separation, and pyrometallurgical and hydrometallurgicalprocessing. Each process, as well as the related physical, chemical, and biological treatments, are discussed. Finally, the problem of developedtechnologies and future subjects for 3R of LIBs are described.
基金JSPS Postdoctoral Fellowship Program 21st Century COE Program, "Mechanical System Innovation"
文摘This paper presents the basic principles of three different types of separating methods and a general guideline for choosing the most effective method for sorting plastic mixtures. It also presents the results of the tests carried out for separation of PVC, ABS and PET from different kinds of plastic mixtures in order to improve the grade of the raw input used in mechanical or feedstock recycling.
基金21st century of COE program, Mechanical Systems Innovation, by the Ministry Education, Culture, Sports, Science and Technology, Japan.
文摘Generally speaking,anionic metal concentrations in wastewater from industries and mineral processing plants are well above the allowed limits for effluent set by the Ministry of Environment of Japan. Nowadays,the removal of anionic ions has been considered difficult and development of new process is desperately needed. In this paper,we report the development of three hydroxide-type adsorbents,illustrating their adsorption efficiency in removing As,Se,Mo and Sb ions from aqueous solutions. The main finding of this work was that the adsorption behavior was influenced very much by both the pH and the adsorbent concentration. Nevertheless,the newly developed hydroxide-type adsorbents were very effective in reducing the concentration of those anionic ions.
基金supported by the National Natural Science Foundation of China(Grant No.52062002 and 51961006)the Open Foundation of Guangxi Key Laboratory of Processing for Nonferrous Metals and Featured Materials,Guangxi University,China(2021GXYSOF01).
文摘A series of single-phase double perovskite Pr1-xGdxBaCo_(2)-yFeyO_(5+σ)(x=0,0.5 and 1,0≤y≤1)materials were engineered through A/B site co-doping strategy to improve the mechanical,electrical and electrochemical properties as potential cathode materials for the application of intermediate solid oxide fuel cells(IT-SOFCs).The corresponding thermochemical stability,thermal expansion behavior,electrical conductivity and cathodic polarization resistance of the materials were systematically investigated.It was found that the A-site dual lanthanide doped Pr_(0.5)Gd_(0.5)BaCo_(2)O_(5+σ)(PGBCO)exhibits improved electrical conductivity,reduced thermal expansion,and comparatively low electrochemical polarization resistance versus single lanthanide double perovskite,PrBaCo_(2)O_(5+σ)(PBCO)and GdBaCo_(2)O_(5+σ)(GBCO)materials.Further investigation on the effect of B-site Fe-doping on Pr_(0.5)Gd_(0.5)BaCo_(2)-yFeyO_(5)+σ(PGBCF-y,0≤y≤1)reveals that all the PGBCF-y compositions exhibit excellent chemical stability with Gd-doped ceria(GDC)at operating temperatures not higher than 1100℃.Besides,doping of Fe in B-site can effectively reduce the thermal expansion coefficients(TECs)of the Pr_(0.5)Gd_(0.5)BaCo_(2)O_(5)+σceramics at 30e1000℃.And the electrochemical impedance spectra(EIS)results show that the PGBCF-y|GDC|PGBCF-y symmetric cells have acceptable low area specific polarization resistances.Further examination of the cathodic polarization and characteristic capacitance from the AC impedance spectra by employing the relaxation time distribution(DRT)method demonstrated that charge transfer is the dominating subprocess for the oxygen transport through the materials.
基金supported by the Global COE Program, "Global Center of Excellence for Mechanical Systems Innovation"the Ministry of Education, Culture, Sports, Science, and Technology, Grant-in-Aid for Scientific Research (A)
文摘Carbon dioxide（CO2） emissions are a leading contributor to the negative effects of global warming. Globally, research has focused on effective means of reducing and mitigating CO2 emissions. In this study, we examined the efficacy of eco-industrial parks（EIPs） and accelerated mineral carbonation techniques in reducing CO2 emissions in South Korea.First, we used Logarithmic Mean Divisia Index（LMDI） analysis to determine the trends in carbon production and mitigation at the existing EIPs. We found that, although CO2 was generated as byproducts and wastes of production at these EIPs, improved energy intensity effects occurred at all EIPs, and we strongly believe that EIPs are a strong alternative to traditional industrial complexes for reducing net carbon emissions. We also examined the optimal conditions for using accelerated mineral carbonation to dispose of hazardous fly ash produced through the incineration of municipal solid wastes at these EIPs. We determined that this technique most efficiently sequestered CO2 when micro-bubbling, low flow rate inlet gas, and ammonia additives were employed.
基金supported by the National Natural Science Foundation of China(Nos.12075066 and 21866007)the Innovation Project of Guangxi Graduate Education(No.YCBZ2022017).
文摘Photocatalytic uranium extraction from radioactive nuclear wastewater and seawater is critical for promoting the sustainable advancement of nuclear industry,but the complexity of real-world environments,particularly the occurrence of anoxic and oxygen-enriched states,presents significant challenges to effective uranium extraction.Here,a layered hollow core–shell structure of Bi_(2)O_(3)/g-C_(3)N_(4)Z-scheme heterojunction photocatalyst has been designed and successfully applied for photocatalytic uranium extraction in both aerobic and oxygen-free conditions,and the extraction efficiency of uranium can reach 98.4%and 99.0%,respectively.Moreover,the photocatalyst still has ultra-high extraction efficiency under the influence of pH,inorganic ions,and other factors.The exceptional capability for uranium extraction is on the one hand due to the distinctive hollow core–shell architecture,which furnishes an abundant quantity of active sites.On the other hand,benefiting from the suitable band gap structure brought by the construction of Z-scheme heterojunction,Bi_(2)O_(3)/g-C_(3)N_(4)exhibits current densities(1.00μA/cm^(2))that are 5.26 and 3.85 times greater than Bi_(2)O_(3)and g-C_(3)N_(4),respectively,and the directional migration mode of Z-scheme carriers significantly prolongs the lifetime of photogenerated charges(1.53 ns),which separately surpass the pure samples by factors of 5.10 and 3.19.Furthermore,the reaction mechanism and reaction process of photocatalytic uranium extraction are investigated in the presence and absence of oxygen,respectively.
