Three-phase centrifuge was used to process oily sludge,and the requirement of mud,oil and water three-phase separation was satisfied through the optimization of parameters. The results showed that when the input quant...Three-phase centrifuge was used to process oily sludge,and the requirement of mud,oil and water three-phase separation was satisfied through the optimization of parameters. The results showed that when the input quantity was lower than 5 m^3/h,the optimal operation parameters of the three-phase centrifuge are shown as follows: the frequency of the main motor and vice motor was 33 and 30 Hz respectively,and the flocculant flow was 0. 7 m^3/h,while the oily sludge temperature was 55 ℃. Water content in the separated sludge decreased from 98% to lower than 70%,and the goal of reduction and harmless treatment of oily sludge could be achieved,which could provide essential conditions for subsequent resource utilization and could be used to guide industrial production.展开更多
[Objectives] To establish the high performance liquid chromatography( HPLC) determination method for oxysophocarpine and optimize the extraction and purification technology of oxysophocarpine from Sophora alopecuroide...[Objectives] To establish the high performance liquid chromatography( HPLC) determination method for oxysophocarpine and optimize the extraction and purification technology of oxysophocarpine from Sophora alopecuroides by inverse three-phase membrane cycle.[Methods]Based on the single-factor experiment,the effects of aqueous phase and organic phase volume ratio,the concentration of sodium hydroxide,concentration of hydrochloric acid and extraction cycle time on extraction process of oxysophocarpine were investigated using orthogonal design method,to determine the optimal extraction process. [Results]The oxysophocarpine was determined by Shim-pack VP-ODS chromatographic column( 4. 6 mm × 250 mm,5 μm),mobile phase was methanol-0. 2% phosphoric acid aqueous solution( 7∶ 93),gradient elution,flow rate was 1 m L/min,the sample size was 5 μm,column temperature was 30℃,detection wavelength was 221 nm. Aqueous phase and organic phase volume ratio was 1∶ 1,hydrochloric acid concentration was 0. 3 mol/L,sodium hydroxide concentration was 0. 75 mol/L,water pump flow rate was 6 m L/min,60 min cycle time. The extraction rate of oxysophocarpine 98. 21 % within 60 min under the best experimental conditions. Oxysophocarpine has good linearity relationship within the range of 0. 01-0. 7 mg/m L( r^2= 0. 9978,n = 6),the respective average recovery rate was 97. 47%( RSD = 1. 95%). [Conclusions] This extraction process is simple in operation,the organic solvent has low consumption,and can be used for extraction of alkaloid.展开更多
Mineral fulvic acid(MFA)was used as an eco-friendly pyrite depressant to recover chalcopyrite by flotation with the use of the butyl xanthate as a collector.Flotation experiments showed that MFA produced a stronger in...Mineral fulvic acid(MFA)was used as an eco-friendly pyrite depressant to recover chalcopyrite by flotation with the use of the butyl xanthate as a collector.Flotation experiments showed that MFA produced a stronger inhibition effect on pyrite than on chalcopyrite.The separation of chalcopyrite from pyrite was realized by introducing 150 mg/L MFA at a pulp pH of approximately 8.0.The copper grade,copper recovery,and separation efficiency were 28.03%,84.79%,and 71.66%,respectively.Surface adsorption tests,zeta potential determinations,and localized electrochemical impedance spectroscopy tests showed that more MFA adsorbed on pyrite than on chalcopyrite,which weakened the subsequent interactions between pyrite and the collector.Atomic force microscope imaging further confirmed the adsorption of MFA on pyrite,and X-ray photoelectron spectroscopy results indicated that hydrophilic Fe-based species on the pyrite surfaces increased after exposure of pyrite to MFA,thereby decreasing the floatability of pyrite.展开更多
Melamine sponge is a major concern for oil-water separation due to its lightweight,high porosity(>99%),cost-effectiveness,impressive mechanical properties,and chemical/thermal stability.However,its amphiphilic natu...Melamine sponge is a major concern for oil-water separation due to its lightweight,high porosity(>99%),cost-effectiveness,impressive mechanical properties,and chemical/thermal stability.However,its amphiphilic nature hinders selective oil absorption in water.Recent strategies to enhance hydrophobicity are reviewed,including synthetic methods and materials,with comprehensive explanations of the mechanisms driven by surface energy and roughness.Key performance indicators for MS in oil-water separation,including adsorption capacity,wettability,stability,emulsion separation,reversible wettability switching,flame retardancy,mechanical properties,and recyclability,are thoroughly discussed.In conclusion,this review provides insights into the future potential and direction of functional melamine sponges in oil-water separation.展开更多
Comprehensive utilization of phosphogypsum(PG)has attracted much attention,especially for the recovery of rare earth elements(REEs)and gypsum due to the issues of stockpile,environmental pollution,and waste of associa...Comprehensive utilization of phosphogypsum(PG)has attracted much attention,especially for the recovery of rare earth elements(REEs)and gypsum due to the issues of stockpile,environmental pollution,and waste of associated resources.Traditional utilization methods suffered the issues of low REEs leaching efficiency,huge amount of CaSO_(4)saturated wastewater and high recovery cost.To solve these issues,this study investigated the occurrence of REEs in PG and the leaching of REEs.The results show that REEs in PG are in the forms of(1)REEs mineral inclusions,(2)REEs isomorphous substitution of Ca^(2+)in gypsum lattice,(3)dispersed soluble REEs salts.Acid leaching results demonstrate that(1)the dissolution of gypsum matrix is the control factor of REEs leaching;(2)H_(2)SO_(4)is a promising leachant considering the recycle of leachate;(3)the gypsum matrix suffers a recrystallization during the acid leaching and releases the soluble REEs from PG to aqueous solution.For the recovery of the undissolved REEs mineral inclusions,wet sieving concentrated 37.1 wt%of the REEs in a 10.7 wt%mass,increasing REEs content from 309 to 1071 ppm.Finally,a green process combining gravity separation and hydrometallurgy is proposed.This process owns the merits of wastewater free,considerable REEs recovery(about 10%increase compared with traditional processes),excellent gypsum purification(>95 wt%CaSO_(4)·2H_(2)O,with<0.06 wt%of soluble P_(2)O_(5) and<0.015 wt%of soluble F)and reagent saving(about 2/3less reagent consumption than non-cyclical leaching).展开更多
Copper and cobalt were recovered from SICOMINES mining waste rock in the Democratic Republic of Congo.The process mineralogy of the samples was analyzed using scanning electron microscopy and energy dispersive spectro...Copper and cobalt were recovered from SICOMINES mining waste rock in the Democratic Republic of Congo.The process mineralogy of the samples was analyzed using scanning electron microscopy and energy dispersive spectroscopy.The results showed that copper minerals exhibited various forms and uneven particle sizes,while cobalt existed in the form of highly dispersed asbolane,and large amounts of easily slimed gangue minerals were filled in the samples,making it difficult to separate copper and cobalt minerals.The particle size range plays a decisive role in selecting the separation method for the copper−cobalt ore.Gravity separation was suitable for particles ranging from 43 to 246μm,while flotation was more effective for particles below 43μm.After ore grinding and particle size classification,applying a combined gravity separation(shaking table)−flotation method yielded concentrated minerals with a copper recovery of 72.83%and a cobalt recovery of 31.13%.展开更多
The research,fabrication and development of piezoelectric nanofibrous materials offer effective solutions to the challenges related to energy consumption and non-renewable resources.However,enhancing their electrical ...The research,fabrication and development of piezoelectric nanofibrous materials offer effective solutions to the challenges related to energy consumption and non-renewable resources.However,enhancing their electrical output still remains a significant challenge.Here,a strategy of inducing constrained phase separation on single nanofibers via shear force was proposed.Employing electrospinning technology,a polyacrylonitrile/polyvinylidene difluoride(PAN/PVDF)nanofibrous membrane was fabricated in one step,which enabled simultaneous piezoelectric and triboelectric conversion within a single-layer membrane.Each nanofiber contained independent components of PAN and PVDF and exhibited a rough surface.The abundant frictional contact points formed between these heterogeneous components contributed to an enhanced endogenous triboelectric output,showcasing an excellent synergistic effect of piezoelectric and triboelectric response in the nanofibrous membrane.Additionally,the component mass ratio influenced the microstructure,piezoelectric conformation and piezoelectric performance of the PAN/PVDF nanofibrous membranes.Through comprehensive performance comparison,the optimal mass ratio of PAN to PVDF was determined to be 9∶1.The piezoelectric devices made of the optimal PAN/PVDF nanofibrous membranes with rough nanofiber surfaces generated an output voltage of 20 V,which was about 1.8 times that of the smooth one at the same component mass ratio.The strategy of constrained phase separation on the surface of individual nanofibers provides a new approach to enhance the output performance of single-layer piezoelectric nanofibrous materials.展开更多
Membrane technology holds significant potential for augmenting or partially substituting conventional separation techniques,such as heatdriven distillation,thereby reducing energy consumption.Organic solvent nanofiltr...Membrane technology holds significant potential for augmenting or partially substituting conventional separation techniques,such as heatdriven distillation,thereby reducing energy consumption.Organic solvent nanofiltration represents an advanced membrane separation technology capable of discerning molecules within a molecular weight range of approximately 100-1000 Da in organic solvents,offering low energy requirements and minimal carbon footprints.Molecular separation in non-polar solvent system,such as toluene,n-hexane,and n-heptane,has gained paramount importance due to their extensive use in the pharmaceutical,biochemical,and petrochemical industries.In this review,we presented recent advancements in membrane materials,membrane fabrication techniques and their promising applications for separation in nonpolar solvent system,encompassing hydrocarbon separation,bioactive molecule purification and organic solvent recovery.Furthermore,this review highlighted the challenges and opportunities associated with membrane scale-up strategies and the direct translation of this promising technology into industrial applications.展开更多
This paper focuses on the preparation of rare earth oxide products from rare earth chloride solutions during the rare earth extraction and separation processes,as well as the recycling of magnesium chloride solutions....This paper focuses on the preparation of rare earth oxide products from rare earth chloride solutions during the rare earth extraction and separation processes,as well as the recycling of magnesium chloride solutions.It proposes the idea of introducing spray pyrolysis technology into the rare earth extraction and separation processes.This paper briefly describes the development history of chloride spray pyrolysis technology,focusing on the research status and application progress of rare earth chloride solution and magnesium chloride solution spray pyrolysis technology,as well as spray pyrolysis equipment.The paper also analyzes the challenges and technical intricacies associated with applying spray pyrolysis technology to chloride solutions in the rare earth extraction and separation processes.Additionally,it explores future trends and proposes strategies to facilitate the full recycling of acids and bases,streamline the process flow,and enhance the prospects for green and low-carbon rare earth metallurgy.展开更多
Separating oil/water mixtures via superhydrophobic stainless steel mesh(SSM)is a kind of efficient methods of treating oily wastewater,and the superhydrophobic SSM with a low cost,simple fabrication process and robust...Separating oil/water mixtures via superhydrophobic stainless steel mesh(SSM)is a kind of efficient methods of treating oily wastewater,and the superhydrophobic SSM with a low cost,simple fabrication process and robust usability remains a challenge.Herein,urushiol-based benzoxazine(U-D)with a strong substrate adhesion and low surface free energy was used to anchor SiO_(2) particles on the SSM surface to obtain a durable superhydrophobic SSM(PU-D/SiO_(2)/SSM)through a simple dip-coating process,meanwhile,epoxy resin was also introduced to further improve the adhesion between coating and SSM.PU-D/SiO_(2)/SSM could successfully separate various immiscible oil-water mixtures with a separation efficiency of over 96%and a flux up to 27100 L/m^(2) h only by gravity,respectively.Especially,the modified SSM could effectively remove water from water-in-oil emulsion with a separation efficiency of 99.7%.Moreover,PU-D/SiO_(2)/SSM had an outstanding reusability,whose water contact angle and separation efficiency only slightly decreased after 20 cycles of separating oil/water mixture.In addition,the modified SSM also displayed a satisfactory abrasion resistance,chemical stability and self-cleaning property.Thereby,the robust PU-D/SiO_(2)/SSM prepared by cheap raw materials and facile dip-coating method exhibits a high potential for separating oil/water mixtures.展开更多
Solvent extraction,a separation and purification technology,is crucial in critical metal metallurgy.Organic solvents commonly used in solvent extraction exhibit disadvantages,such as high volatility,high toxicity,and ...Solvent extraction,a separation and purification technology,is crucial in critical metal metallurgy.Organic solvents commonly used in solvent extraction exhibit disadvantages,such as high volatility,high toxicity,and flammability,causing a spectrum of hazards to human health and environmental safety.Neoteric solvents have been recognized as potential alternatives to these harmful organic solvents.In the past two decades,several neoteric solvents have been proposed,including ionic liquids(ILs)and deep eutectic solvents(DESs).DESs have gradually become the focus of green solvents owing to several advantages,namely,low toxicity,degradability,and low cost.In this critical review,their classification,formation mechanisms,preparation methods,characterization technologies,and special physicochemical properties based on the most recent advancements in research have been systematically described.Subsequently,the major separation and purification applications of DESs in critical metal metallurgy were comprehensively summarized.Finally,future opportunities and challenges of DESs were explored in the current research area.In conclusion,this review provides valuable insights for improving our overall understanding of DESs,and it holds important potential for expanding separation and purification applications in critical metal metallurgy.展开更多
We report a robust pillar-layered metal-organic framework,Zn‑tfbdc‑dabco(tfbdc:tetrafluoroterephthal-ate,dabco:1,4-diazabicyclo[2.2.2]octane),featuring the fluorinated pore environment,for the preferential binding of ...We report a robust pillar-layered metal-organic framework,Zn‑tfbdc‑dabco(tfbdc:tetrafluoroterephthal-ate,dabco:1,4-diazabicyclo[2.2.2]octane),featuring the fluorinated pore environment,for the preferential binding of propane over propylene and thus highly inverse selective separation of propane/propylene mixture.The inverse propane-selective performance of Zn‑tfbdc‑dabco for the propane/propylene separation was validated by single-component gas adsorption isotherms,isosteric enthalpy of adsorption calculations,ideal adsorbed solution theory calculations,along with the breakthrough experiment.The customized fluorinated networks served as a propane-trap to form more interactions with the exposed hydrogen atoms of propane,as unveiled by the simulation studies at the molecular level.With the advantage of inverse propane-selective adsorption behavior,high adsorption capacity,good cycling stability,and low isosteric enthalpy of adsorption,Zn‑tfbdc‑dabco can be a promising candidate adsorbent for the challenging propane/propylene separation to realize one-step purification of the target propylene substance.展开更多
In this study,the Stokes formula is used to analyze the separation effect of three-phase separators used in a Oilfield Central Processing Facility.The considered main influencing factors include(but are not limited to...In this study,the Stokes formula is used to analyze the separation effect of three-phase separators used in a Oilfield Central Processing Facility.The considered main influencing factors include(but are not limited to)the typical size of oil and water droplets,the residence time and temperature of fluid and the dosage of demulsifier.Using the“Specification for Oil and Gas Separators”as a basis,the control loops and operating parameters of each separator are optimized Considering the Halfaya Oilfield as a testbed,it is shown that the proposed approach can lead to good results in the production stage.展开更多
Removing H_(2)S and CO_(2)is of great significance for natural gas purification.With excellent gas affinity and tunable structure,ionic liquids(ILs) have been regarded as nontrivial candidates for fabricating polymer-...Removing H_(2)S and CO_(2)is of great significance for natural gas purification.With excellent gas affinity and tunable structure,ionic liquids(ILs) have been regarded as nontrivial candidates for fabricating polymer-based membranes.Herein,we firstly reported the incorporation of protic ILs (PILs) having ether-rich and carboxylate sites (ECPILs) into poly(ether-block-amide)(Pebax) matrix for efficient separation H_(2)S and CO_(2)from CH_(4).Notably,the optimal permeability of H_(2)S reaches up to 4310 Barrer (40C,0.50 bar) in Pebax/ECPIL membranes,along with H_(2)S/CH_(4)and (H_(2)StCO_(2))/CH_(4)selectivity of 97.7 and 112.3,respectively.These values are increased by 1125%,160.8%and 145.9%compared to those in neat Pebax membrane.Additionally,the solubility and diffusion coefficients of the gases were measured,demonstrating that ECPIL can simultaneously strengthen the dissolution and diffusion of H_(2)S and CO_(2),thus elevating the permeability and permselectivity.By using quantum chemical calculations and FT-IR spectroscopy,the highly reversible multi-site hydrogen bonding interaction between ECPILs and H_(2)S was revealed,which is responsible for the fast permeation of H_(2)S and good selectivity.Furthermore,H_(2)S/CO_(2)/CH_(4)(3/3/94 mol/mol) ternary mixed gas can be efficiently and stably separated by Pebax/ECPIL membrane for at least 100 h.Overall,this work not only illustrates that PILs with ether-rich and carboxylate hydrogen bonding sites are outstanding materials for simultaneous removal of H_(2)S and CO_(2),but may also provide a novel insight into the design of membrane materials for natural gas upgrading.展开更多
Instrument separation is a critical complication during root canal therapy,impacting treatment success and long-term tooth preservation.The etiology of instrument separation is multifactorial,involving the intricate a...Instrument separation is a critical complication during root canal therapy,impacting treatment success and long-term tooth preservation.The etiology of instrument separation is multifactorial,involving the intricate anatomy of the root canal system,instrument-related factors,and instrumentation techniques.Instrument separation can hinder thorough cleaning,shaping,and obturation of the root canal,posing challenges to successful treatment outcomes.Although retrieval of separated instrument is often feasible,it carries risks including perforation,excessive removal of tooth structure and root fractures.Effective management of separated instruments requires a comprehensive understanding of the contributing factors,meticulous preoperative assessment,and precise evaluation of the retrieval difficulty.The application of appropriate retrieval techniques is essential to minimize complications and optimize clinical outcomes.The current manuscript provides a framework for understanding the causes,risk factors,and clinical management principles of instrument separation.By integrating effective strategies,endodontists can enhance decision-making,improve endodontic treatment success and ensure the preservation of natural dentition.展开更多
Mixed matrix membranes(MMMs)have demonstrated significant promise in energy-intensive gas separations by amalgamating the unique properties of fillers with the facile processability of polymers.However,achieving a sim...Mixed matrix membranes(MMMs)have demonstrated significant promise in energy-intensive gas separations by amalgamating the unique properties of fillers with the facile processability of polymers.However,achieving a simultaneous enhancement of permeability and selectivity remains a formidable challenge,due to the difficulty of achieving an optimal match between polymers and fillers.In this study,we incorporate a porous carbon-based zinc oxide composite(C@ZnO)into high-permeability polymers of intrinsic microporosity(PIMs)to fabricate MMMs.The dipole–dipole interaction between C@ZnO and PIMs ensures their exceptional compatibility,mitigating the formation of non-selective voids in the resulting MMMs.Concurrently,C@ZnO with abundant interconnected pores can provide additional low-resistance pathways for gas transport in MMMs.As a result,the CO_(2) permeability of the optimized C@ZnO/PIM-1 MMMs is elevated to 13,215 barrer,while the CO_(2)/N_(2) and CO_(2)/CH_(4) selectivity reached 21.5 and 14.4,respectively,substantially surpassing the 2008 Robeson upper bound.Additionally,molecular simulation results further corroborate that the augmented membrane gas selectivity is attributed to the superior CO_(2) affinity of C@ZnO.In summary,we believe that this work not only expands the application of MMMs for gas separation but also heralds a paradigm shift in the application of porous carbon materials.展开更多
The presence of chirality,a fundamental attribute found in nature,is of great significance in the field of pharmaceutical science.Chiral drugs are unique in that their molecular structure is non-superimposable on its ...The presence of chirality,a fundamental attribute found in nature,is of great significance in the field of pharmaceutical science.Chiral drugs are unique in that their molecular structure is non-superimposable on its mirror image.This stereoisomerism significantly impacts the functionality,metabolic pathway,effectiveness,and safety of chiral medications.The enantiomers of chiral drugs can exhibit diverse pharmacological effects in the human body.As a result,it is essential to separate and purify chiral drugs effectively.Despite the abundance of reports on chiral drug separation membranes,there is a dearth of comprehensive reviews.This paper aims to fill this gap by providing a thorough review from a materials perspective,with a focus on the design and construction of chiral drug separation membranes.Furthermore,it systematically analyzes the separation mechanisms employed by these membranes.The paper also delves into the challenges and prospects related to chiral drug separation membranes,with the intention of imparting valuable insights for further research and development in this field.展开更多
To achieve high power rating and low current harmonics of motor drive,this paper develops a dual three-phase open-winding permanent magnet synchronous motor(DTP-OW-PMSM)drive with the DC-link voltage ratio of 2:1:1.Ba...To achieve high power rating and low current harmonics of motor drive,this paper develops a dual three-phase open-winding permanent magnet synchronous motor(DTP-OW-PMSM)drive with the DC-link voltage ratio of 2:1:1.Based on this topology,this paper proposes a DTP four-level space vector pulse width modulation(DTP-FL SVPWM)strategy.First,two identical three-phase four-level space vector diagrams are constructed and divided.Then,three adjacent vectors nearest to the reference vector in each diagram are selected for the vector synthesis to guarantee high modulation precision and low switching frequency.Furthermore,to avoid the modulation error caused by the voltage deviation,the proposed DTP-FL SVPWM strategy is further optimized through unified duty ratio compensation(UDRC).The effectiveness of the proposed strategy is verified through experiments.展开更多
The limitations of swirl separation in removing microfine oil droplets in water have driven the development of hydrocyclone technology coupled with multiphase or multifield techniques.To enhance microfine oil droplets...The limitations of swirl separation in removing microfine oil droplets in water have driven the development of hydrocyclone technology coupled with multiphase or multifield techniques.To enhance microfine oil droplets separation,a novel hydrocyclone separation coupled with fiber coalescence(HCCFC) was designed.The interaction between fiber balls and oil droplets inside the hydrocyclone,including droplet coalescence and breakage,was investigated.The influence of different operating parameters on separation efficiency was discussed.The results showed that fiber balls promoted oil droplet coalescence when the inlet droplet size(D_(43)) was below 22.37 μm but caused droplet breakage above this threshold.The coalescence performance of HCCFC improved with increasing inlet oil content but declined beyond 450 mg·L^(-1).Separation experiments confirmed that HCCFC outperformed conventional hydrocyclone,with separation efficiency increasing by 2.9% to 20.0%.As the fiber ball content and inlet flow rate increased,the separation efficiency showed a trend of first increasing and then decreasing.Additionally,HCCFC's separation efficiency varied with inlet oil droplet size distribution,showing the most significant enhancement when D_(43) was 22.37 μm,where separation efficiency increased by 14.4%.These findings offer insights into the development and application of multiphase coupled with hydrocyclone technology.展开更多
Chirality is not only a natural phenomenon but also a bridge between chemistry and life sciences.An effective way to obtain a single enantiomer is through racemates resolution.Recent literature shows that chiral metal...Chirality is not only a natural phenomenon but also a bridge between chemistry and life sciences.An effective way to obtain a single enantiomer is through racemates resolution.Recent literature shows that chiral metal-organic frameworks(CMOFs)have many applications in various fields because of their diverse topologies and functionalities.This review outlines the design idea and summarizes the latest synthesis strategies and applications of CMOFs.It highlights key advances and issues in the separation domain.In conclusion,the review provides perspectives on the challenges and prospective advancements of CMOFs materials and CMOFs-based separation technologies.展开更多
文摘Three-phase centrifuge was used to process oily sludge,and the requirement of mud,oil and water three-phase separation was satisfied through the optimization of parameters. The results showed that when the input quantity was lower than 5 m^3/h,the optimal operation parameters of the three-phase centrifuge are shown as follows: the frequency of the main motor and vice motor was 33 and 30 Hz respectively,and the flocculant flow was 0. 7 m^3/h,while the oily sludge temperature was 55 ℃. Water content in the separated sludge decreased from 98% to lower than 70%,and the goal of reduction and harmless treatment of oily sludge could be achieved,which could provide essential conditions for subsequent resource utilization and could be used to guide industrial production.
基金Supported by Project of National Natural Science Foundation(21162030)
文摘[Objectives] To establish the high performance liquid chromatography( HPLC) determination method for oxysophocarpine and optimize the extraction and purification technology of oxysophocarpine from Sophora alopecuroides by inverse three-phase membrane cycle.[Methods]Based on the single-factor experiment,the effects of aqueous phase and organic phase volume ratio,the concentration of sodium hydroxide,concentration of hydrochloric acid and extraction cycle time on extraction process of oxysophocarpine were investigated using orthogonal design method,to determine the optimal extraction process. [Results]The oxysophocarpine was determined by Shim-pack VP-ODS chromatographic column( 4. 6 mm × 250 mm,5 μm),mobile phase was methanol-0. 2% phosphoric acid aqueous solution( 7∶ 93),gradient elution,flow rate was 1 m L/min,the sample size was 5 μm,column temperature was 30℃,detection wavelength was 221 nm. Aqueous phase and organic phase volume ratio was 1∶ 1,hydrochloric acid concentration was 0. 3 mol/L,sodium hydroxide concentration was 0. 75 mol/L,water pump flow rate was 6 m L/min,60 min cycle time. The extraction rate of oxysophocarpine 98. 21 % within 60 min under the best experimental conditions. Oxysophocarpine has good linearity relationship within the range of 0. 01-0. 7 mg/m L( r^2= 0. 9978,n = 6),the respective average recovery rate was 97. 47%( RSD = 1. 95%). [Conclusions] This extraction process is simple in operation,the organic solvent has low consumption,and can be used for extraction of alkaloid.
基金supported by Fundamental Research Projects of Yunnan Province,China(Nos.202101BE070001-009,202301AU070189).
文摘Mineral fulvic acid(MFA)was used as an eco-friendly pyrite depressant to recover chalcopyrite by flotation with the use of the butyl xanthate as a collector.Flotation experiments showed that MFA produced a stronger inhibition effect on pyrite than on chalcopyrite.The separation of chalcopyrite from pyrite was realized by introducing 150 mg/L MFA at a pulp pH of approximately 8.0.The copper grade,copper recovery,and separation efficiency were 28.03%,84.79%,and 71.66%,respectively.Surface adsorption tests,zeta potential determinations,and localized electrochemical impedance spectroscopy tests showed that more MFA adsorbed on pyrite than on chalcopyrite,which weakened the subsequent interactions between pyrite and the collector.Atomic force microscope imaging further confirmed the adsorption of MFA on pyrite,and X-ray photoelectron spectroscopy results indicated that hydrophilic Fe-based species on the pyrite surfaces increased after exposure of pyrite to MFA,thereby decreasing the floatability of pyrite.
基金supported by the National Natural Science Foundation of China(Nos.52372093 and 52102145)the Key R&D Program of Shaanxi Province(Nos.2023GXLH-045 and 2022SF-168)+4 种基金the Xi’an Programs for Science and Technology Plan(Nos.2020KJRC0090 and 21XJZZ0045)the Opening Project of Shanxi Key Laboratory of Advanced Manufacturing Technology(No.XJZZ202001)the Xi’an Municipal Bureau of Science and Technology(No.21XJZZ0054)the Open Foundation of Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry,Ministry of Education,Shaanxi University of Science and Technology(No.KFKT2021-01)the Shaanxi Collaborative Innovation Center of Industrial Auxiliary Chemistry and Technology,Shaanxi University of Science and Technology(No.KFKT2021-01).
文摘Melamine sponge is a major concern for oil-water separation due to its lightweight,high porosity(>99%),cost-effectiveness,impressive mechanical properties,and chemical/thermal stability.However,its amphiphilic nature hinders selective oil absorption in water.Recent strategies to enhance hydrophobicity are reviewed,including synthetic methods and materials,with comprehensive explanations of the mechanisms driven by surface energy and roughness.Key performance indicators for MS in oil-water separation,including adsorption capacity,wettability,stability,emulsion separation,reversible wettability switching,flame retardancy,mechanical properties,and recyclability,are thoroughly discussed.In conclusion,this review provides insights into the future potential and direction of functional melamine sponges in oil-water separation.
基金Project supported by the National Natural Science Foundation of China(52104354)the National Natural Science Foundation of China(51674036)+1 种基金Joint Fund for Nuclear Technology Innovation Sponsored by the National Natural Science Foundation of Chinathe China National Nuclear Corporation(U2067201)。
文摘Comprehensive utilization of phosphogypsum(PG)has attracted much attention,especially for the recovery of rare earth elements(REEs)and gypsum due to the issues of stockpile,environmental pollution,and waste of associated resources.Traditional utilization methods suffered the issues of low REEs leaching efficiency,huge amount of CaSO_(4)saturated wastewater and high recovery cost.To solve these issues,this study investigated the occurrence of REEs in PG and the leaching of REEs.The results show that REEs in PG are in the forms of(1)REEs mineral inclusions,(2)REEs isomorphous substitution of Ca^(2+)in gypsum lattice,(3)dispersed soluble REEs salts.Acid leaching results demonstrate that(1)the dissolution of gypsum matrix is the control factor of REEs leaching;(2)H_(2)SO_(4)is a promising leachant considering the recycle of leachate;(3)the gypsum matrix suffers a recrystallization during the acid leaching and releases the soluble REEs from PG to aqueous solution.For the recovery of the undissolved REEs mineral inclusions,wet sieving concentrated 37.1 wt%of the REEs in a 10.7 wt%mass,increasing REEs content from 309 to 1071 ppm.Finally,a green process combining gravity separation and hydrometallurgy is proposed.This process owns the merits of wastewater free,considerable REEs recovery(about 10%increase compared with traditional processes),excellent gypsum purification(>95 wt%CaSO_(4)·2H_(2)O,with<0.06 wt%of soluble P_(2)O_(5) and<0.015 wt%of soluble F)and reagent saving(about 2/3less reagent consumption than non-cyclical leaching).
基金National Key Research and Development Program of China(No.2020YFC1909202)Major Science and Technology Program of Yunnan Province,China(No.202202AB080012)for financial support。
文摘Copper and cobalt were recovered from SICOMINES mining waste rock in the Democratic Republic of Congo.The process mineralogy of the samples was analyzed using scanning electron microscopy and energy dispersive spectroscopy.The results showed that copper minerals exhibited various forms and uneven particle sizes,while cobalt existed in the form of highly dispersed asbolane,and large amounts of easily slimed gangue minerals were filled in the samples,making it difficult to separate copper and cobalt minerals.The particle size range plays a decisive role in selecting the separation method for the copper−cobalt ore.Gravity separation was suitable for particles ranging from 43 to 246μm,while flotation was more effective for particles below 43μm.After ore grinding and particle size classification,applying a combined gravity separation(shaking table)−flotation method yielded concentrated minerals with a copper recovery of 72.83%and a cobalt recovery of 31.13%.
基金National Natural Science Foundation of China(No.52373281)National Energy-Saving and Low-Carbon Materials Production and Application Demonstration Platform Program,China(No.TC220H06N)。
文摘The research,fabrication and development of piezoelectric nanofibrous materials offer effective solutions to the challenges related to energy consumption and non-renewable resources.However,enhancing their electrical output still remains a significant challenge.Here,a strategy of inducing constrained phase separation on single nanofibers via shear force was proposed.Employing electrospinning technology,a polyacrylonitrile/polyvinylidene difluoride(PAN/PVDF)nanofibrous membrane was fabricated in one step,which enabled simultaneous piezoelectric and triboelectric conversion within a single-layer membrane.Each nanofiber contained independent components of PAN and PVDF and exhibited a rough surface.The abundant frictional contact points formed between these heterogeneous components contributed to an enhanced endogenous triboelectric output,showcasing an excellent synergistic effect of piezoelectric and triboelectric response in the nanofibrous membrane.Additionally,the component mass ratio influenced the microstructure,piezoelectric conformation and piezoelectric performance of the PAN/PVDF nanofibrous membranes.Through comprehensive performance comparison,the optimal mass ratio of PAN to PVDF was determined to be 9∶1.The piezoelectric devices made of the optimal PAN/PVDF nanofibrous membranes with rough nanofiber surfaces generated an output voltage of 20 V,which was about 1.8 times that of the smooth one at the same component mass ratio.The strategy of constrained phase separation on the surface of individual nanofibers provides a new approach to enhance the output performance of single-layer piezoelectric nanofibrous materials.
基金supported by the National Natural Science Foundation of China(Grant No.2230081973)Shanghai Pilot Program for Basic Research(22TQ1400100-4).
文摘Membrane technology holds significant potential for augmenting or partially substituting conventional separation techniques,such as heatdriven distillation,thereby reducing energy consumption.Organic solvent nanofiltration represents an advanced membrane separation technology capable of discerning molecules within a molecular weight range of approximately 100-1000 Da in organic solvents,offering low energy requirements and minimal carbon footprints.Molecular separation in non-polar solvent system,such as toluene,n-hexane,and n-heptane,has gained paramount importance due to their extensive use in the pharmaceutical,biochemical,and petrochemical industries.In this review,we presented recent advancements in membrane materials,membrane fabrication techniques and their promising applications for separation in nonpolar solvent system,encompassing hydrocarbon separation,bioactive molecule purification and organic solvent recovery.Furthermore,this review highlighted the challenges and opportunities associated with membrane scale-up strategies and the direct translation of this promising technology into industrial applications.
基金supported by the National Key Research and Development Program of China(2022YFB3504501)the National Natural Science Foundation of China(52274355)。
文摘This paper focuses on the preparation of rare earth oxide products from rare earth chloride solutions during the rare earth extraction and separation processes,as well as the recycling of magnesium chloride solutions.It proposes the idea of introducing spray pyrolysis technology into the rare earth extraction and separation processes.This paper briefly describes the development history of chloride spray pyrolysis technology,focusing on the research status and application progress of rare earth chloride solution and magnesium chloride solution spray pyrolysis technology,as well as spray pyrolysis equipment.The paper also analyzes the challenges and technical intricacies associated with applying spray pyrolysis technology to chloride solutions in the rare earth extraction and separation processes.Additionally,it explores future trends and proposes strategies to facilitate the full recycling of acids and bases,streamline the process flow,and enhance the prospects for green and low-carbon rare earth metallurgy.
基金Funded by the National Natural Science Foundation of China(No.22165019)。
文摘Separating oil/water mixtures via superhydrophobic stainless steel mesh(SSM)is a kind of efficient methods of treating oily wastewater,and the superhydrophobic SSM with a low cost,simple fabrication process and robust usability remains a challenge.Herein,urushiol-based benzoxazine(U-D)with a strong substrate adhesion and low surface free energy was used to anchor SiO_(2) particles on the SSM surface to obtain a durable superhydrophobic SSM(PU-D/SiO_(2)/SSM)through a simple dip-coating process,meanwhile,epoxy resin was also introduced to further improve the adhesion between coating and SSM.PU-D/SiO_(2)/SSM could successfully separate various immiscible oil-water mixtures with a separation efficiency of over 96%and a flux up to 27100 L/m^(2) h only by gravity,respectively.Especially,the modified SSM could effectively remove water from water-in-oil emulsion with a separation efficiency of 99.7%.Moreover,PU-D/SiO_(2)/SSM had an outstanding reusability,whose water contact angle and separation efficiency only slightly decreased after 20 cycles of separating oil/water mixture.In addition,the modified SSM also displayed a satisfactory abrasion resistance,chemical stability and self-cleaning property.Thereby,the robust PU-D/SiO_(2)/SSM prepared by cheap raw materials and facile dip-coating method exhibits a high potential for separating oil/water mixtures.
基金financially supported by the Original Exploration Project of the National Natural Science Foundation of China(No.52150079)the National Natural Science Foundation of China(Nos.U22A20130,U2004215,and 51974280)+1 种基金the Natural Science Foundation of Henan Province of China(No.232300421196)the Project of Zhongyuan Critical Metals Laboratory of China(Nos.GJJSGFYQ202304,GJJSGFJQ202306,GJJSGFYQ202323,GJJSGFYQ202308,and GJJSGFYQ202307)。
文摘Solvent extraction,a separation and purification technology,is crucial in critical metal metallurgy.Organic solvents commonly used in solvent extraction exhibit disadvantages,such as high volatility,high toxicity,and flammability,causing a spectrum of hazards to human health and environmental safety.Neoteric solvents have been recognized as potential alternatives to these harmful organic solvents.In the past two decades,several neoteric solvents have been proposed,including ionic liquids(ILs)and deep eutectic solvents(DESs).DESs have gradually become the focus of green solvents owing to several advantages,namely,low toxicity,degradability,and low cost.In this critical review,their classification,formation mechanisms,preparation methods,characterization technologies,and special physicochemical properties based on the most recent advancements in research have been systematically described.Subsequently,the major separation and purification applications of DESs in critical metal metallurgy were comprehensively summarized.Finally,future opportunities and challenges of DESs were explored in the current research area.In conclusion,this review provides valuable insights for improving our overall understanding of DESs,and it holds important potential for expanding separation and purification applications in critical metal metallurgy.
文摘We report a robust pillar-layered metal-organic framework,Zn‑tfbdc‑dabco(tfbdc:tetrafluoroterephthal-ate,dabco:1,4-diazabicyclo[2.2.2]octane),featuring the fluorinated pore environment,for the preferential binding of propane over propylene and thus highly inverse selective separation of propane/propylene mixture.The inverse propane-selective performance of Zn‑tfbdc‑dabco for the propane/propylene separation was validated by single-component gas adsorption isotherms,isosteric enthalpy of adsorption calculations,ideal adsorbed solution theory calculations,along with the breakthrough experiment.The customized fluorinated networks served as a propane-trap to form more interactions with the exposed hydrogen atoms of propane,as unveiled by the simulation studies at the molecular level.With the advantage of inverse propane-selective adsorption behavior,high adsorption capacity,good cycling stability,and low isosteric enthalpy of adsorption,Zn‑tfbdc‑dabco can be a promising candidate adsorbent for the challenging propane/propylene separation to realize one-step purification of the target propylene substance.
基金This study was supported by the Natural Science Foundation of Shandong Province(Grant No.ZR2021QE030).
文摘In this study,the Stokes formula is used to analyze the separation effect of three-phase separators used in a Oilfield Central Processing Facility.The considered main influencing factors include(but are not limited to)the typical size of oil and water droplets,the residence time and temperature of fluid and the dosage of demulsifier.Using the“Specification for Oil and Gas Separators”as a basis,the control loops and operating parameters of each separator are optimized Considering the Halfaya Oilfield as a testbed,it is shown that the proposed approach can lead to good results in the production stage.
基金sponsored by the National Natural Science Foundation of China (Nos. 22308145, 22208140, 22178159, 22078145)Natural Science Foundation of Jiangsu Province (BK20230791)Postgraduate Research Innovation Program of Jiangsu Province (KYCX24_0165)。
文摘Removing H_(2)S and CO_(2)is of great significance for natural gas purification.With excellent gas affinity and tunable structure,ionic liquids(ILs) have been regarded as nontrivial candidates for fabricating polymer-based membranes.Herein,we firstly reported the incorporation of protic ILs (PILs) having ether-rich and carboxylate sites (ECPILs) into poly(ether-block-amide)(Pebax) matrix for efficient separation H_(2)S and CO_(2)from CH_(4).Notably,the optimal permeability of H_(2)S reaches up to 4310 Barrer (40C,0.50 bar) in Pebax/ECPIL membranes,along with H_(2)S/CH_(4)and (H_(2)StCO_(2))/CH_(4)selectivity of 97.7 and 112.3,respectively.These values are increased by 1125%,160.8%and 145.9%compared to those in neat Pebax membrane.Additionally,the solubility and diffusion coefficients of the gases were measured,demonstrating that ECPIL can simultaneously strengthen the dissolution and diffusion of H_(2)S and CO_(2),thus elevating the permeability and permselectivity.By using quantum chemical calculations and FT-IR spectroscopy,the highly reversible multi-site hydrogen bonding interaction between ECPILs and H_(2)S was revealed,which is responsible for the fast permeation of H_(2)S and good selectivity.Furthermore,H_(2)S/CO_(2)/CH_(4)(3/3/94 mol/mol) ternary mixed gas can be efficiently and stably separated by Pebax/ECPIL membrane for at least 100 h.Overall,this work not only illustrates that PILs with ether-rich and carboxylate hydrogen bonding sites are outstanding materials for simultaneous removal of H_(2)S and CO_(2),but may also provide a novel insight into the design of membrane materials for natural gas upgrading.
文摘Instrument separation is a critical complication during root canal therapy,impacting treatment success and long-term tooth preservation.The etiology of instrument separation is multifactorial,involving the intricate anatomy of the root canal system,instrument-related factors,and instrumentation techniques.Instrument separation can hinder thorough cleaning,shaping,and obturation of the root canal,posing challenges to successful treatment outcomes.Although retrieval of separated instrument is often feasible,it carries risks including perforation,excessive removal of tooth structure and root fractures.Effective management of separated instruments requires a comprehensive understanding of the contributing factors,meticulous preoperative assessment,and precise evaluation of the retrieval difficulty.The application of appropriate retrieval techniques is essential to minimize complications and optimize clinical outcomes.The current manuscript provides a framework for understanding the causes,risk factors,and clinical management principles of instrument separation.By integrating effective strategies,endodontists can enhance decision-making,improve endodontic treatment success and ensure the preservation of natural dentition.
基金financial support from the National Natural Science Foundation of China(Nos.22108258 and 52003251)Program for Science&Technology Innovation Talents in Universities of Henan Province(24HASTIT004)+1 种基金Outstanding Youth Fund of Henan Scientific Committee(222300420085)Science and Technology Joint Project of Henan Province(222301420041)。
文摘Mixed matrix membranes(MMMs)have demonstrated significant promise in energy-intensive gas separations by amalgamating the unique properties of fillers with the facile processability of polymers.However,achieving a simultaneous enhancement of permeability and selectivity remains a formidable challenge,due to the difficulty of achieving an optimal match between polymers and fillers.In this study,we incorporate a porous carbon-based zinc oxide composite(C@ZnO)into high-permeability polymers of intrinsic microporosity(PIMs)to fabricate MMMs.The dipole–dipole interaction between C@ZnO and PIMs ensures their exceptional compatibility,mitigating the formation of non-selective voids in the resulting MMMs.Concurrently,C@ZnO with abundant interconnected pores can provide additional low-resistance pathways for gas transport in MMMs.As a result,the CO_(2) permeability of the optimized C@ZnO/PIM-1 MMMs is elevated to 13,215 barrer,while the CO_(2)/N_(2) and CO_(2)/CH_(4) selectivity reached 21.5 and 14.4,respectively,substantially surpassing the 2008 Robeson upper bound.Additionally,molecular simulation results further corroborate that the augmented membrane gas selectivity is attributed to the superior CO_(2) affinity of C@ZnO.In summary,we believe that this work not only expands the application of MMMs for gas separation but also heralds a paradigm shift in the application of porous carbon materials.
基金supported by the Foundation Research Project of Kaili University(No.2025ZD007)the National Key Research and Development Program of China(No.2021YFB3801503)the Joint Research Program of Shaoxing University and Shaoxing Institute,Zhejiang University(No.2023LHLG006),China.
文摘The presence of chirality,a fundamental attribute found in nature,is of great significance in the field of pharmaceutical science.Chiral drugs are unique in that their molecular structure is non-superimposable on its mirror image.This stereoisomerism significantly impacts the functionality,metabolic pathway,effectiveness,and safety of chiral medications.The enantiomers of chiral drugs can exhibit diverse pharmacological effects in the human body.As a result,it is essential to separate and purify chiral drugs effectively.Despite the abundance of reports on chiral drug separation membranes,there is a dearth of comprehensive reviews.This paper aims to fill this gap by providing a thorough review from a materials perspective,with a focus on the design and construction of chiral drug separation membranes.Furthermore,it systematically analyzes the separation mechanisms employed by these membranes.The paper also delves into the challenges and prospects related to chiral drug separation membranes,with the intention of imparting valuable insights for further research and development in this field.
基金supported in part by the National Natural Science Foundation of China under Grant 62303333in part by the Project of Hetao Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone under Grant HZQB-KCZYB-2020083.
文摘To achieve high power rating and low current harmonics of motor drive,this paper develops a dual three-phase open-winding permanent magnet synchronous motor(DTP-OW-PMSM)drive with the DC-link voltage ratio of 2:1:1.Based on this topology,this paper proposes a DTP four-level space vector pulse width modulation(DTP-FL SVPWM)strategy.First,two identical three-phase four-level space vector diagrams are constructed and divided.Then,three adjacent vectors nearest to the reference vector in each diagram are selected for the vector synthesis to guarantee high modulation precision and low switching frequency.Furthermore,to avoid the modulation error caused by the voltage deviation,the proposed DTP-FL SVPWM strategy is further optimized through unified duty ratio compensation(UDRC).The effectiveness of the proposed strategy is verified through experiments.
基金sponsored by the National Science Fund for Distinguished Young Scholars,China(22225804)the National Natural Science Foundation of China(22078102,22408101,22308105)。
文摘The limitations of swirl separation in removing microfine oil droplets in water have driven the development of hydrocyclone technology coupled with multiphase or multifield techniques.To enhance microfine oil droplets separation,a novel hydrocyclone separation coupled with fiber coalescence(HCCFC) was designed.The interaction between fiber balls and oil droplets inside the hydrocyclone,including droplet coalescence and breakage,was investigated.The influence of different operating parameters on separation efficiency was discussed.The results showed that fiber balls promoted oil droplet coalescence when the inlet droplet size(D_(43)) was below 22.37 μm but caused droplet breakage above this threshold.The coalescence performance of HCCFC improved with increasing inlet oil content but declined beyond 450 mg·L^(-1).Separation experiments confirmed that HCCFC outperformed conventional hydrocyclone,with separation efficiency increasing by 2.9% to 20.0%.As the fiber ball content and inlet flow rate increased,the separation efficiency showed a trend of first increasing and then decreasing.Additionally,HCCFC's separation efficiency varied with inlet oil droplet size distribution,showing the most significant enhancement when D_(43) was 22.37 μm,where separation efficiency increased by 14.4%.These findings offer insights into the development and application of multiphase coupled with hydrocyclone technology.
基金fund by the National Natural Science Foundation of China(Grant Nos.:82473880 and 82003705)the Shanghai Science and Technology Innovation Foundation(Grant Nos.:23010500200 and 23ZR1422700)the Postdoctoral Fellowship Program of CPSF(Program No.:GZC20231528).
文摘Chirality is not only a natural phenomenon but also a bridge between chemistry and life sciences.An effective way to obtain a single enantiomer is through racemates resolution.Recent literature shows that chiral metal-organic frameworks(CMOFs)have many applications in various fields because of their diverse topologies and functionalities.This review outlines the design idea and summarizes the latest synthesis strategies and applications of CMOFs.It highlights key advances and issues in the separation domain.In conclusion,the review provides perspectives on the challenges and prospective advancements of CMOFs materials and CMOFs-based separation technologies.
