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
The environment-friendly and efficient selective separation of chalcopyrite and molybdenite poses a challenge in mineral pro-cessing.In this study,gum Arabic(GA)was initially proposed as a novel depressant for the sel...The environment-friendly and efficient selective separation of chalcopyrite and molybdenite poses a challenge in mineral pro-cessing.In this study,gum Arabic(GA)was initially proposed as a novel depressant for the selective separation of molybdenite from chalcopyrite during flotation.Microflotation results indicated that the inhibitory capacity of GA was stronger toward molybdenite than chalcopyrite.At pH 8.0 with 20 mg/L GA addition,the recovery rate of chalcopyrite in the concentrate obtained from mixed mineral flota-tion was 67.49%higher than that of molybdenite.Furthermore,the mechanism of GA was systematically investigated by various surface characterization techniques.Contact angle tests indicated that after GA treatment,the hydrophobicity of the molybdenite surface signifi-cantly decreased,but that of the chalcopyrite surface showed no apparent change.Fourier transform-infrared spectroscopy and X-ray photoelectron spectroscopy revealed a weak interaction force between GA and chalcopyrite.By contrast,GA was primarily adsorbed onto the molybdenite surface through chemical chelation,with possible contributions from hydrogen bonding and hydrophobic interactions.Pre-adsorbed GA could prevent butyl xanthate from being adsorbed onto molybdenite.Scanning electron microscopy–energy-dispersive spectrometry further indicated that GA was primarily adsorbed onto the“face”of molybdenite rather than the“edge.”Therefore,GA could be a promising molybdenite depressant for the flotation separation of Cu–Mo.展开更多
Due to the lack of effective screening systems in the rare earth waste recycling industry,the composition of rare earth elements in rare earth waste is complex and difficult to separate.In response to such problems,by...Due to the lack of effective screening systems in the rare earth waste recycling industry,the composition of rare earth elements in rare earth waste is complex and difficult to separate.In response to such problems,by studying the reaction behavior between various elements in rare earth waste and cobalt chloride,we propose a process path for the separation and recovery of iron,cerium and other rare earth elements using cobalt chloride roasting.The experiments on simulated wastes show that the leaching rates of the Nd,Sm,Gd,Pr can reach 98.31%,94.5%,93.87%and 72.05%under the optimal process conditions,respectively.Ce and iron remain in the leaching residue in the form of CeO_(2)and CoFe_(2)O_(4),respectively.And through a simple magnetic separation process,CeO_(2)and CoFe_(2)O_(4)can be enriched in non-magnetic leaching residue and magnetic leaching residue,respectively.The cerium content in the leaching residue composed of cobalt ferrite is only 1.95%.Therefore,this method is beneficial to the separation and high-value utilization of iron,cerium,and other rare earth elements in the waste system.The research results can provide theoretical reference for the low-cost and high-value recovery of rare earth secondary resources.展开更多
Selective separation of phenanthrene(PHE)from aromatic isomer mixtures poses a significant challenge in industry due to the similar physical properties of PHE and its isomer anthracene(ANT).Herein,we report the self-a...Selective separation of phenanthrene(PHE)from aromatic isomer mixtures poses a significant challenge in industry due to the similar physical properties of PHE and its isomer anthracene(ANT).Herein,we report the self-assembly of a water-soluble Pd_(2)L_(2) cage 1 with a large hydrophobic cavity,formed from novel macrocyclic ligands(L)and cis-Pd(Ⅱ).Cage 1 can selectively encapsulate PHE instead of ANT.Based on host-vip recognition followed by extraction,we achieve a remarkable 99%purity of PHE separation from an equimolar mixture of PHE and ANT using cage 1 in aqueous solution.Importantly,the separation performance of PHE using cage 1 remains unaffected even after five extraction cycles,demonstrating its robustness.This work highlights the potential of supramolecular cages for efficient and cost-effective PHE separation from the isomer ANT in aqueous solutions using such promising host-vip strategy.展开更多
Stemming from the high costs and environmental pollution associated with the use of sodium sulfide in the separation and extraction processes of molybdenum bismuth ore,calcium hypochlorite was introduced as a substitu...Stemming from the high costs and environmental pollution associated with the use of sodium sulfide in the separation and extraction processes of molybdenum bismuth ore,calcium hypochlorite was introduced as a substitute to facilitate the cleaner production of low-grade molybdenum bismuth ore in this study.The effects of calcium hypochlorite on molybdenite,bismuthinite,and pyrite were investigated through micro-flotation,flotation kinetics,batch flotation,Fourier transform infrared(FTIR)spectra,scanning electron microscopy energy dispersion spectra(SEM-EDS),and inductively coupled plasma-optical emission spectra(ICP-OES).The flotation tests results showed that calcium hypochlorite could selectively depress bismuthinite and pyrite.In comparison to sodium sulfide,calcium hypochlorite not only improved the flotation indicators for molybdenum and bismuth concentrates but also reduced the dosage of flotation reagents.Moreover,the chemical oxygen demand(COD)of tailings wastewater significantly decreased when using calcium hypochlorite as a depressant.Mechanism research revealed that the use of calcium hypochlorite as a depressant led to BiOCl precipitation on bismuthinite,which hindered the attachment of the collector.In summary,calcium hypochlorite serves as a more efficient and environmentally friendly depressant compared to sodium sulfide in the industrial production processes of low-grade molybdenum bismuth ore.展开更多
[Objective] The aim was to separate chromium-resistant microorganism from soil contaminated by chromium.[Method] Separation and purification technique was used as follows：different concentrations of Cr^6＋ were added...[Objective] The aim was to separate chromium-resistant microorganism from soil contaminated by chromium.[Method] Separation and purification technique was used as follows：different concentrations of Cr^6＋ were added into medium,and chromium-resistant fungi were screened after separations and domestications.The selected fungi were under preliminary identification according to its morphological and colony characteristics.Then,related biological characteristics were studied,including measurement of growth curve,growing effects by temperature,pH value and osmotic pressure.[Result] The Cr（VI） with concentration of 1 000 mg/L was separated and selected from soils in ten different places contaminated seriously by heavy metal in adjacent region of Yulin City.Considering its morphological and colony characteristics,it was preliminarily identified as saccharomycetes,which can well grow within 15-37 ℃,and whose most suitable temperature was 28℃.Bacterial strain can grow well with pH of 4-10,and the optimum pH was 7.2;besides,it can grow well with NaCl concentration of 0.5%-5.0%.Through the experiment,the bacteria was found with resistance not only to chromium,but also to heavy metals such as Pb＋Cu,Cu＋Fe,Pb＋Fe,and Pb＋Cu＋Fe.[Conclusion] The fungi selected from the experiment were of good adaptability to natural environment,and it also had resistance to other heavy metals.展开更多
This study investigated the effects of H_(2)O_(2)treatment on xanthate interaction and flotation separation of chalcopyrite and pyrite by making use of a series of laboratory flotation experiments and surface analysis...This study investigated the effects of H_(2)O_(2)treatment on xanthate interaction and flotation separation of chalcopyrite and pyrite by making use of a series of laboratory flotation experiments and surface analysis techniques.Flotation test results showed that H2O2 treatment influenced the flotation behaviors of the two minerals;however,flotation of pyrite was depressed more significantly than that of the chalcopyrite.Under well-controlled H_(2)O_(2)concentration,the selective separation of chalcopyrite from pyrite was realized at pH 9.0,at which the recovery of chalcopyrite was over 84%and that of pyrite was less than 24%.Zeta potential,UV-visible and IR spectrum measurements revealed that the collector interacted differently with the two minerals after H_(2)O_(2)treatment,and the surface of chalcopyrite adsorbed much greater amount of xanthate than that of the pyrite.IR and XPS analyses showed that the H_(2)O_(2)treatment significantly changed the surface properties of pyrite to very hydrophilic species that inhibited the adsorption of collector and thus depressed the floatability of pyrite.While,the surface of chalcopyrite remained mildly inert to H_(2)O_(2),as a result,the adsorption of xanthate and its oxidation to dixanthogen were very effective,which enhanced the flotation of chalcopyrite.展开更多
An experimental investigation was presented on the separation of Cu（Ⅱ）, Zn（Ⅱ）, and Cd（Ⅱ） from a rich sulfate leachate of zinc slag by solvent extraction. The results of orthogonal experiments indicate that LI...An experimental investigation was presented on the separation of Cu（Ⅱ）, Zn（Ⅱ）, and Cd（Ⅱ） from a rich sulfate leachate of zinc slag by solvent extraction. The results of orthogonal experiments indicate that LIX 984N is highly selective and very efficient in the extraction of Cu（Ⅱ）, and the analysis of variance indicates that the sequence of parameters according to their influence on the separation efficiency is phase ratio 〉 LIX 984N concentration 〉 pH value 〉 extraction time. The optimal condition for copper extraction is obtained as 25% of LIX 984N concentration, 7 rain of extraction time, 3：2 of phase ratio O/A, and pH = 1.7. The separation of Zn（Ⅱ） and Cd（Ⅱ） was performed after the copper extraction from the raffinate. Comparative analysis of the separation with di-2-ethylhexyl phosphoric acid （D2EHPA）, D2EHPA-tributyl- phosophate （TBP） synergistic extracting system, and 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester （HEHEHP） was made at pH = 2.0. It is demonstrated that the extraction efficiency with D2EHPA is improved after being saponified by sodium hydroxide, and D2EHPA-TBP synergistic extracting, as well as HEHEHP, has a superior selectivity to Zn（Ⅱ） over Cd（Ⅱ）.展开更多
Neodymium ion imprinted polymer（Nd^3＋-IIP） particles for selective solid-phase extraction of Nd^3＋ were prepared and determined with inductively coupled plasma atomic emission spectrometry（ICP-AES）.The unleached...Neodymium ion imprinted polymer（Nd^3＋-IIP） particles for selective solid-phase extraction of Nd^3＋ were prepared and determined with inductively coupled plasma atomic emission spectrometry（ICP-AES）.The unleached Nd^3＋-IIP particles were prepared by the copoly-merization of Nd^3＋-5,7-dichloroquinoline-8-ol-4-vinylpyridine ternary complex with styrene and divinyl benzene, then Nd^3＋ was leached to obtain Nd^3＋-IIP particles.The adsorption capacity of the Nd3＋-IIP was 35.18 mg/g.The largest selectivity coefficient for Nd3＋ in the presence of competitive ions such as La^3＋, Ce^3＋, Pr^3＋ and Sm^3＋ was over 110.The proposed method was validated by analyzing two certified reference materials（GBW07301a sediment and GBW07401 soil） and the determined values were in a good agreement with standard values.The method was convenient, selective, sensitive and applicable to the determination of trace Nd^3＋ in environmental samples with complicated matrix.展开更多
A novel ion-imprinted polymer, lead ion-imprinted micro-beads with combination of two functional monomers, was synthesized using the W/O/W polymerization method. Two functional monomers, 1,12-dodecanediol-O,O’-diphen...A novel ion-imprinted polymer, lead ion-imprinted micro-beads with combination of two functional monomers, was synthesized using the W/O/W polymerization method. Two functional monomers, 1,12-dodecanediol-O,O’-diphenyl-phosphonic acid （DDDPA） and 4-vinylpyridine, were used to form a suitable construction with micro-pores fitting the template and recognition sites. The eflects of adsorbent dosage, solution pH and the competitive ions on the adsorption and separation eflciency of lead ions were investigated. The lead ion-imprinted micro-beads were eflcient for lead ions removal from aqueous solution in a broad pH range （4–9）, when the adsorbent dosage was above 0.1 g/L. The adsorption process obeyed the pseudo second-order kinetics model and it only took half an hour to reach the equilibrium. The adsorption isotherm of lead ion was described by the Langmuir model （R2 0.99） with a maximum adsorption capacity of 116.9 mg/g. In the presence of competitive ions Co2＋ and Cd2＋, the lead ion-imprinted micro-beads showed a high selectivity for lead ions. The selectivity coeficient of Pb2＋/Cd2＋ and Pb2＋/Co2＋are 99.3 and 114.7, respectively.展开更多
Selective separation of CO_(2)/CH_(4)and C2 H_(2)/CH_(4)are promising for their high-purity industrial demand and scientific research on account of the similar molecular radius and physical properties.In this work,a u...Selective separation of CO_(2)/CH_(4)and C2 H_(2)/CH_(4)are promising for their high-purity industrial demand and scientific research on account of the similar molecular radius and physical properties.In this work,a unique 3 D microporous MOF material[Cu(SiF6)(sdi)2]·solvents(1,sdi=1,1’-sulfonyldiimidazole)was successfully constructed by cross-linking 1 D coordination polymer chains.The dense functional active sites on the inner walls of the channel of la can provide strong binding affinities to CO_(2),C2 H_(2),and thus effectively improve the gas separation performance of CO_(2)/CH_(4)and C2 H_(2)/CH_(4).展开更多
Selective separation of gallium from aluminum by ion flotation using sodium dodecyl sulfate(SDS) as an anionic surfactant and fluoride as an inorganic ligand was investigated. The experimental results were analyzed us...Selective separation of gallium from aluminum by ion flotation using sodium dodecyl sulfate(SDS) as an anionic surfactant and fluoride as an inorganic ligand was investigated. The experimental results were analyzed using the stability constants and speciation diagrams of fluoride metal complexes. The presence of fluoride in the solution has a positive influence upon the separation of gallium from aluminum. The results show that increasing the fluoride concentration makes a more effective separation of gallium from aluminum because of a simultaneous increase in the complexion of aluminum with fluoride and a change in the electrical charge of the aluminum(ALF_4^-). The dehydration model of LIU and DOYLE was also applied to compare the ion flotation and the selectivity coefficients of gallium over aluminum with experimental results.展开更多
Novel porous aromatic frameworks（PAF-53 and PAF-54） have been obtained by the polymerization of amino compound（p-phenylenediamine and melamine） and cyanuric chloride. They display a certain amount of CO2 adsorptio...Novel porous aromatic frameworks（PAF-53 and PAF-54） have been obtained by the polymerization of amino compound（p-phenylenediamine and melamine） and cyanuric chloride. They display a certain amount of CO2 adsorption capacity and highly selective separation of CO2/CH4 and CO2/N2 as 18.1 and83 by Henry Law respectively. They may be applied as ideal adsorbents to separate and capture CO2.展开更多
An innovative process was proposed to recover metallic aluminum from secondary aluminum dross(SAD)by alkali roasting−water leaching.Thermodynamic calculations and experimental results were used to illustrate the phase...An innovative process was proposed to recover metallic aluminum from secondary aluminum dross(SAD)by alkali roasting−water leaching.Thermodynamic calculations and experimental results were used to illustrate the phase transformation and reaction mechanism of the alkali roasting process.The leaching behaviors of roasted residue were also analyzed.Under optimal conditions,the aluminum extraction rate reached 93.08%.In addition,the kinetics of the water leaching of roasted products was studied through shrinking core model,and it was revealed that the leaching process of aluminum was in accord with diffusion control.The apparent activation energy of the leaching process was calculated to be 3.44 kJ/mol.Based on the above study,the underlying mechanism of the alkali roasting−water leaching was clarified.展开更多
Polycyclic aromatic hydrocarbons(PAHs)play an important role in the industry,and the development of new materials for the selective separation of PAHs is of great significance.In this work,we report a hexahedral metal...Polycyclic aromatic hydrocarbons(PAHs)play an important role in the industry,and the development of new materials for the selective separation of PAHs is of great significance.In this work,we report a hexahedral metal-organic cage with low symmetry by subcomponent self-assembly.In this cage,the eight ZnII centers adopt an interestin∧∧/△△△△△△or∧∧∧∧∧∧/△△configuration.This cage with a cavity volume of 520˚A3 can bind anthracene,phenanthrene,and pyrene to form 1:1 host-vip complexes,while the bigger triphenylene,chrysene,perylene,and coronene cannot be encapsulated.The binding constant Ka of pyrene is about 1.110×10^(3)(mol/L)^(−1),which is more than an order of magnitude larger than that of anthracene and phenanthrene(111(mol/L)^(−1),277(mol/L)^(−1),respectively).X-ray structure studies reveal that the pyrene is located in the cavity and stabilized by multiple C–H…πinteractions.After separation from a mixture of PAHs,pyrene with>96.1%purity can be obtained.This work provides a useful method for the first time for the selective separation of pyrene from PAHs mixture by utilizing a metal-organic cage as the material,making it a useful tool for purifying and separating specific compounds from complex mixtures.展开更多
A novel amine-modified pillar[5]arene bonded porous silica adsorbent(DETA-P5S)was designed to be applied to dynamic CO_(2)adsorption and selective separation of CO_(2)over N_(2)and CH_(4)gases mixture.The results demo...A novel amine-modified pillar[5]arene bonded porous silica adsorbent(DETA-P5S)was designed to be applied to dynamic CO_(2)adsorption and selective separation of CO_(2)over N_(2)and CH_(4)gases mixture.The results demonstrated that reasonable introduction of DETA into the BE-P5 bonded silica support has sig nificantly increased the adsorption capacity of CO_(2).The DETA-P5S has the optimal adsorption capacity of 9.1 mmol/g with 5 vol%CO_(2)at 40℃.The main reason of this increased capacity could be attributed to the enhanced CO_(2)diffusion into porous adsorbent for its better dispersion in the pores of amine pillar[5]arene cavity and active site of DETA.Furthermore,the dynamic saturation adsorption capacitie of DETA-P5S were 7.11(0.37)and 6.18(0.44)mmol/g for CO_(2)/N_(2)and CO_(2)/CH_(4),respectively,both the ga mixtures showed high separation selectivity.Simultaneously,the DETA-P5S can maintain outstanding CO_(2)adsorption capacity after fifteen regeneration cycles.Consequently,the designed DETA-P5S could serve a a promising adsorbent for CO_(2)capture and storage.展开更多
Porous carbon membranes were favorably fabricated through the pyrolysis of polyacrylonitrile（PAN） precursors, which were prepared with a template-free technique-thermally induced phase separation. These carbon membr...Porous carbon membranes were favorably fabricated through the pyrolysis of polyacrylonitrile（PAN） precursors, which were prepared with a template-free technique-thermally induced phase separation. These carbon membranes possess hierarchical pores, including cellular macropores across the whole membranes and much small pores in the matrix as well as on the pore walls. Nitrogen adsorption indicates micropores（1.47 and 1.84 nm） and mesopores（2.21 nm） exist inside the carbon membranes, resulting in their specific surface area as large as 1062 m2/g. The carbon membranes were used to adsorb organic dyes（methyl orange, Congo red, and rhodamine B） from aqueous solutions based on their advantages of hierarchical pore structures and large specific surface area. It is particularly noteworthy that the membranes present a selective adsorption towards methyl orange, whose molecular size（1.2 nm） is smaller than those of Congo red（2.3 nm） and rhodamine B（1.8 nm）. This attractive result can be attributed to the steric structure matching between the molecular size and the pore size, rather than electrostatic attraction. Furthermore, the used carbon membranes can be easily regenerated by hydrochloric acid, and their recovery adsorption ratio maintains above 90% even in the third cycle. This work may provide a new route for carbon-based adsorbents with hierarchical pores via a template-free approach, which could be promisingly applied to selectively remove dye contaminants in aqueous effluents.展开更多
Molecularly imprinted polymers (MIPs) have great potential as adsorbents for selective adsorption and separation of nucleoside compounds,but effectively enhancing the affinity of recognition sites by adjusting the for...Molecularly imprinted polymers (MIPs) have great potential as adsorbents for selective adsorption and separation of nucleoside compounds,but effectively enhancing the affinity of recognition sites by adjusting the forces between template molecules and functional monomers remains an important challenge.In this work,a surface imprinting strategy was used to construct bowl-shaped molecularly imprinted composite sorbents (BHPN@MIPs) based on polydopamine (PDA) particles and have achieved selective separation and purification of 2'-deoxyadenosine (dA).Where by the base complementary pairing interaction of the combined template molecule d A and the pyrimidine functional monomer can enhance the preassembly force,and the hydrophilic bowl-shaped PDA can provide a larger storage space contact efficiency of d A in the test solution,causing the site utilization much higher and improving the kinetic adsorption performance.The equilibrium adsorption time and maximum adsorption capacity of60 min and 328.45μmol·g^(-1)were observed by static adsorption experiments,and the selectivity experimental results showed an imprinting factor IF of 1.30.After four adsorption–desorption cycles,the initial adsorption equilibrium adsorption capacity of BHPN@MIPs still retained 91.14%.By evaluating the selective adsorption of d A in spiked human serum solutions,BHPN@MIPs can be used to selectively enrich and analyze target d A in complex biological samples.展开更多
A Co-based two-dimensional（2 D） microporous metal-organic frameworks, [Co2（TMTA）（DMF）2（H2O）2]·NO3-·DMF（UPC-32） has been synthesized based on 4,4’,4’’-（2,4,6-trimethylbenzene-1,3,5-triyl）triben...A Co-based two-dimensional（2 D） microporous metal-organic frameworks, [Co2（TMTA）（DMF）2（H2O）2]·NO3-·DMF（UPC-32） has been synthesized based on 4,4’,4’’-（2,4,6-trimethylbenzene-1,3,5-triyl）tribenzoic acid（H3TMTA）. UPC-32 features a 2 D microporous framework exhibits high adsorption of H2（118.2 cm3/g, 1.05 wt%, at 77 K）, and adsorption heat（Qst） of CO2（34–46 k J/mol）. UPC-32 with narrow distance between layers（3.8 ？） exhibits high selectivity of C3H6/CH4（31.46） and C3H8/CH4（28.04） at298 K and 1 bar. It is the first 2 D Co-MOF that showed selective separation of C3 hydrocarbon from CH4.展开更多
The membrane method based on adaptive wettability shows great advantages in oil-water separation.At present,researches focus on the excellent application performance of the membrane material,while the quantitative ana...The membrane method based on adaptive wettability shows great advantages in oil-water separation.At present,researches focus on the excellent application performance of the membrane material,while the quantitative analysis of interactions in oil-water separation is rarely recognized.Herein,we constructed an adaptable wettability membrane with multiple polymer networks by polydopamine(PDA)and mussel-inspired amphiphilic polymer.Based on the Owens three-probe liquid method,the surface energy of the modified membrane was verified to meet the adaptive wettability conditions,with surface energies(γ-8)of 147.6 mJ m^(−2)(superhydrophilic/underwater superoleophobic)and 49.87 mJ m^(−2)(superhydrophobic/superoleophobic),respectively.The adhesion or repulsion of the membrane to the oil phase under different conditions during the separation process was quantified by the chemical probe AFM technique.In addition,the oil-water selective separation mechanism was further analyzed in a simplified membrane microchannel model.The results show that the different wetting produces capillary additional pressure in opposite directions,resulting in different energies to be overcome when the oil or water passes through the microchannels,thus achieving selective separation.展开更多
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supported by the National Key Research and Development Program of China(Nos.2022YFC2904502 and 2022YFC2904501)the Major Science and Technology Projects in Yunnan Province,China(No.202202AB080012).
文摘The environment-friendly and efficient selective separation of chalcopyrite and molybdenite poses a challenge in mineral pro-cessing.In this study,gum Arabic(GA)was initially proposed as a novel depressant for the selective separation of molybdenite from chalcopyrite during flotation.Microflotation results indicated that the inhibitory capacity of GA was stronger toward molybdenite than chalcopyrite.At pH 8.0 with 20 mg/L GA addition,the recovery rate of chalcopyrite in the concentrate obtained from mixed mineral flota-tion was 67.49%higher than that of molybdenite.Furthermore,the mechanism of GA was systematically investigated by various surface characterization techniques.Contact angle tests indicated that after GA treatment,the hydrophobicity of the molybdenite surface signifi-cantly decreased,but that of the chalcopyrite surface showed no apparent change.Fourier transform-infrared spectroscopy and X-ray photoelectron spectroscopy revealed a weak interaction force between GA and chalcopyrite.By contrast,GA was primarily adsorbed onto the molybdenite surface through chemical chelation,with possible contributions from hydrogen bonding and hydrophobic interactions.Pre-adsorbed GA could prevent butyl xanthate from being adsorbed onto molybdenite.Scanning electron microscopy–energy-dispersive spectrometry further indicated that GA was primarily adsorbed onto the“face”of molybdenite rather than the“edge.”Therefore,GA could be a promising molybdenite depressant for the flotation separation of Cu–Mo.
基金Project supported by China Baowu Low Carbon Metallurgy Innovation Foundation(BWLCF202121)Jiangxi Provincial Key Laboratory of Flash Green Development and Recycling(20193BCD40019)+1 种基金Academic and Technical Leaders of Major Disciplines in Jiangxi Province(20213BCJ22003)Yichun Science and Technology Plan Project(2023YBKJGG04)。
文摘Due to the lack of effective screening systems in the rare earth waste recycling industry,the composition of rare earth elements in rare earth waste is complex and difficult to separate.In response to such problems,by studying the reaction behavior between various elements in rare earth waste and cobalt chloride,we propose a process path for the separation and recovery of iron,cerium and other rare earth elements using cobalt chloride roasting.The experiments on simulated wastes show that the leaching rates of the Nd,Sm,Gd,Pr can reach 98.31%,94.5%,93.87%and 72.05%under the optimal process conditions,respectively.Ce and iron remain in the leaching residue in the form of CeO_(2)and CoFe_(2)O_(4),respectively.And through a simple magnetic separation process,CeO_(2)and CoFe_(2)O_(4)can be enriched in non-magnetic leaching residue and magnetic leaching residue,respectively.The cerium content in the leaching residue composed of cobalt ferrite is only 1.95%.Therefore,this method is beneficial to the separation and high-value utilization of iron,cerium,and other rare earth elements in the waste system.The research results can provide theoretical reference for the low-cost and high-value recovery of rare earth secondary resources.
基金supported by the National Key Research and Development Program of China(Nos.2022YFA1503300 and 2021YFA1500400)the National Natural Science Foundation of China(Nos.22171262,21825107 and 22171264)the Science Foundation of Fujian Province(Nos.2021J01516 and 2021J02016)。
文摘Selective separation of phenanthrene(PHE)from aromatic isomer mixtures poses a significant challenge in industry due to the similar physical properties of PHE and its isomer anthracene(ANT).Herein,we report the self-assembly of a water-soluble Pd_(2)L_(2) cage 1 with a large hydrophobic cavity,formed from novel macrocyclic ligands(L)and cis-Pd(Ⅱ).Cage 1 can selectively encapsulate PHE instead of ANT.Based on host-vip recognition followed by extraction,we achieve a remarkable 99%purity of PHE separation from an equimolar mixture of PHE and ANT using cage 1 in aqueous solution.Importantly,the separation performance of PHE using cage 1 remains unaffected even after five extraction cycles,demonstrating its robustness.This work highlights the potential of supramolecular cages for efficient and cost-effective PHE separation from the isomer ANT in aqueous solutions using such promising host-vip strategy.
基金Projects(2022YFC2904504-4,2019YFC0408300)supported by the National Key R&D Program of ChinaProject(HB202302)supported by the Open Foundation of State Environmental Protection Key Laboratory of Mineral Metallurgical Resources Utilization and Pollution Control,China+1 种基金Project(51634009)supported by the National Natural Science Foundation of ChinaProject(B14034)supported by the National“111”Project,China。
文摘Stemming from the high costs and environmental pollution associated with the use of sodium sulfide in the separation and extraction processes of molybdenum bismuth ore,calcium hypochlorite was introduced as a substitute to facilitate the cleaner production of low-grade molybdenum bismuth ore in this study.The effects of calcium hypochlorite on molybdenite,bismuthinite,and pyrite were investigated through micro-flotation,flotation kinetics,batch flotation,Fourier transform infrared(FTIR)spectra,scanning electron microscopy energy dispersion spectra(SEM-EDS),and inductively coupled plasma-optical emission spectra(ICP-OES).The flotation tests results showed that calcium hypochlorite could selectively depress bismuthinite and pyrite.In comparison to sodium sulfide,calcium hypochlorite not only improved the flotation indicators for molybdenum and bismuth concentrates but also reduced the dosage of flotation reagents.Moreover,the chemical oxygen demand(COD)of tailings wastewater significantly decreased when using calcium hypochlorite as a depressant.Mechanism research revealed that the use of calcium hypochlorite as a depressant led to BiOCl precipitation on bismuthinite,which hindered the attachment of the collector.In summary,calcium hypochlorite serves as a more efficient and environmentally friendly depressant compared to sodium sulfide in the industrial production processes of low-grade molybdenum bismuth ore.
基金Supported by Chinese National Natural Science Foundation(30960008 )Educational Commission of Guangxi Province(200810LX393)+2 种基金Starting Project of Yulin Normal College,Guangxi ProvinceSpecialized Research Project of Yulin Normal College,Guangxi Province (2011YJZX01)Project Supported by the Science Foundation for Young Scientists of Guangxi Yulin Normal College (2010YJQN24)~~
文摘[Objective] The aim was to separate chromium-resistant microorganism from soil contaminated by chromium.[Method] Separation and purification technique was used as follows：different concentrations of Cr^6＋ were added into medium,and chromium-resistant fungi were screened after separations and domestications.The selected fungi were under preliminary identification according to its morphological and colony characteristics.Then,related biological characteristics were studied,including measurement of growth curve,growing effects by temperature,pH value and osmotic pressure.[Result] The Cr（VI） with concentration of 1 000 mg/L was separated and selected from soils in ten different places contaminated seriously by heavy metal in adjacent region of Yulin City.Considering its morphological and colony characteristics,it was preliminarily identified as saccharomycetes,which can well grow within 15-37 ℃,and whose most suitable temperature was 28℃.Bacterial strain can grow well with pH of 4-10,and the optimum pH was 7.2;besides,it can grow well with NaCl concentration of 0.5%-5.0%.Through the experiment,the bacteria was found with resistance not only to chromium,but also to heavy metals such as Pb＋Cu,Cu＋Fe,Pb＋Fe,and Pb＋Cu＋Fe.[Conclusion] The fungi selected from the experiment were of good adaptability to natural environment,and it also had resistance to other heavy metals.
基金Projects(51704329,51705540)supported by the National Natural Science Foundation of ChinaProject(2015CX005)supported by the Innovation Driven Plan of Central South University,China+1 种基金Project(B14034)supported by the National“111”Project,ChinaProject(2018TP1002)supported by the Collaborative Innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources,China
文摘This study investigated the effects of H_(2)O_(2)treatment on xanthate interaction and flotation separation of chalcopyrite and pyrite by making use of a series of laboratory flotation experiments and surface analysis techniques.Flotation test results showed that H2O2 treatment influenced the flotation behaviors of the two minerals;however,flotation of pyrite was depressed more significantly than that of the chalcopyrite.Under well-controlled H_(2)O_(2)concentration,the selective separation of chalcopyrite from pyrite was realized at pH 9.0,at which the recovery of chalcopyrite was over 84%and that of pyrite was less than 24%.Zeta potential,UV-visible and IR spectrum measurements revealed that the collector interacted differently with the two minerals after H_(2)O_(2)treatment,and the surface of chalcopyrite adsorbed much greater amount of xanthate than that of the pyrite.IR and XPS analyses showed that the H_(2)O_(2)treatment significantly changed the surface properties of pyrite to very hydrophilic species that inhibited the adsorption of collector and thus depressed the floatability of pyrite.While,the surface of chalcopyrite remained mildly inert to H_(2)O_(2),as a result,the adsorption of xanthate and its oxidation to dixanthogen were very effective,which enhanced the flotation of chalcopyrite.
文摘An experimental investigation was presented on the separation of Cu（Ⅱ）, Zn（Ⅱ）, and Cd（Ⅱ） from a rich sulfate leachate of zinc slag by solvent extraction. The results of orthogonal experiments indicate that LIX 984N is highly selective and very efficient in the extraction of Cu（Ⅱ）, and the analysis of variance indicates that the sequence of parameters according to their influence on the separation efficiency is phase ratio 〉 LIX 984N concentration 〉 pH value 〉 extraction time. The optimal condition for copper extraction is obtained as 25% of LIX 984N concentration, 7 rain of extraction time, 3：2 of phase ratio O/A, and pH = 1.7. The separation of Zn（Ⅱ） and Cd（Ⅱ） was performed after the copper extraction from the raffinate. Comparative analysis of the separation with di-2-ethylhexyl phosphoric acid （D2EHPA）, D2EHPA-tributyl- phosophate （TBP） synergistic extracting system, and 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester （HEHEHP） was made at pH = 2.0. It is demonstrated that the extraction efficiency with D2EHPA is improved after being saponified by sodium hydroxide, and D2EHPA-TBP synergistic extracting, as well as HEHEHP, has a superior selectivity to Zn（Ⅱ） over Cd（Ⅱ）.
文摘Neodymium ion imprinted polymer（Nd^3＋-IIP） particles for selective solid-phase extraction of Nd^3＋ were prepared and determined with inductively coupled plasma atomic emission spectrometry（ICP-AES）.The unleached Nd^3＋-IIP particles were prepared by the copoly-merization of Nd^3＋-5,7-dichloroquinoline-8-ol-4-vinylpyridine ternary complex with styrene and divinyl benzene, then Nd^3＋ was leached to obtain Nd^3＋-IIP particles.The adsorption capacity of the Nd3＋-IIP was 35.18 mg/g.The largest selectivity coefficient for Nd3＋ in the presence of competitive ions such as La^3＋, Ce^3＋, Pr^3＋ and Sm^3＋ was over 110.The proposed method was validated by analyzing two certified reference materials（GBW07301a sediment and GBW07401 soil） and the determined values were in a good agreement with standard values.The method was convenient, selective, sensitive and applicable to the determination of trace Nd^3＋ in environmental samples with complicated matrix.
基金supported by the National Natural Science Foundation of China (No. 41072173)the National Science & Technology Pillar Program in the Eleventh Five-year Plan Period of China (No. 2006BAJ04A07)
文摘A novel ion-imprinted polymer, lead ion-imprinted micro-beads with combination of two functional monomers, was synthesized using the W/O/W polymerization method. Two functional monomers, 1,12-dodecanediol-O,O’-diphenyl-phosphonic acid （DDDPA） and 4-vinylpyridine, were used to form a suitable construction with micro-pores fitting the template and recognition sites. The eflects of adsorbent dosage, solution pH and the competitive ions on the adsorption and separation eflciency of lead ions were investigated. The lead ion-imprinted micro-beads were eflcient for lead ions removal from aqueous solution in a broad pH range （4–9）, when the adsorbent dosage was above 0.1 g/L. The adsorption process obeyed the pseudo second-order kinetics model and it only took half an hour to reach the equilibrium. The adsorption isotherm of lead ion was described by the Langmuir model （R2 0.99） with a maximum adsorption capacity of 116.9 mg/g. In the presence of competitive ions Co2＋ and Cd2＋, the lead ion-imprinted micro-beads showed a high selectivity for lead ions. The selectivity coeficient of Pb2＋/Cd2＋ and Pb2＋/Co2＋are 99.3 and 114.7, respectively.
基金supported by the National Natural Science Foundation of China(NSFC,Nos.91856124 and 21531005)Nature Science Fund of Tianjin,China(No.19JCZDJC37200)。
文摘Selective separation of CO_(2)/CH_(4)and C2 H_(2)/CH_(4)are promising for their high-purity industrial demand and scientific research on account of the similar molecular radius and physical properties.In this work,a unique 3 D microporous MOF material[Cu(SiF6)(sdi)2]·solvents(1,sdi=1,1’-sulfonyldiimidazole)was successfully constructed by cross-linking 1 D coordination polymer chains.The dense functional active sites on the inner walls of the channel of la can provide strong binding affinities to CO_(2),C2 H_(2),and thus effectively improve the gas separation performance of CO_(2)/CH_(4)and C2 H_(2)/CH_(4).
基金the Iran National Elites FoundationIranian Mines&Mining Industries Development&the Renovation and Geological Survey of Iran for financial support
文摘Selective separation of gallium from aluminum by ion flotation using sodium dodecyl sulfate(SDS) as an anionic surfactant and fluoride as an inorganic ligand was investigated. The experimental results were analyzed using the stability constants and speciation diagrams of fluoride metal complexes. The presence of fluoride in the solution has a positive influence upon the separation of gallium from aluminum. The results show that increasing the fluoride concentration makes a more effective separation of gallium from aluminum because of a simultaneous increase in the complexion of aluminum with fluoride and a change in the electrical charge of the aluminum(ALF_4^-). The dehydration model of LIU and DOYLE was also applied to compare the ion flotation and the selectivity coefficients of gallium over aluminum with experimental results.
基金support of the National Natural Science Foundation of China(No.0831002)Major International (Regional) Joint Research Project(No.21120102034)
文摘Novel porous aromatic frameworks（PAF-53 and PAF-54） have been obtained by the polymerization of amino compound（p-phenylenediamine and melamine） and cyanuric chloride. They display a certain amount of CO2 adsorption capacity and highly selective separation of CO2/CH4 and CO2/N2 as 18.1 and83 by Henry Law respectively. They may be applied as ideal adsorbents to separate and capture CO2.
基金the financial support from the National Natural Science Foundation of China(Nos.51804342,51874356)the National Key R&D Program of China(Nos.2019YFC1907301,2020YFC1909203)the Innovation Driven Project of Central South University,China(No.2020CX038).
文摘An innovative process was proposed to recover metallic aluminum from secondary aluminum dross(SAD)by alkali roasting−water leaching.Thermodynamic calculations and experimental results were used to illustrate the phase transformation and reaction mechanism of the alkali roasting process.The leaching behaviors of roasted residue were also analyzed.Under optimal conditions,the aluminum extraction rate reached 93.08%.In addition,the kinetics of the water leaching of roasted products was studied through shrinking core model,and it was revealed that the leaching process of aluminum was in accord with diffusion control.The apparent activation energy of the leaching process was calculated to be 3.44 kJ/mol.Based on the above study,the underlying mechanism of the alkali roasting−water leaching was clarified.
基金the National Natural Science Foundation of China(Nos.22171106,21731002,21975104,21871172 and 22201101)the Guangdong Major Project of Basic and Applied Research(No.2019B030302009)+3 种基金Guangdong Natural Science Foundation(No.2022A1515011937)the Guangzhou Science and Technology Program(No.202002030411)the Fundamental Research Funds for the Central Universities(No.21622103)the China Postdoctoral Science Foundation(No.2022M711327),and Jinan University.
文摘Polycyclic aromatic hydrocarbons(PAHs)play an important role in the industry,and the development of new materials for the selective separation of PAHs is of great significance.In this work,we report a hexahedral metal-organic cage with low symmetry by subcomponent self-assembly.In this cage,the eight ZnII centers adopt an interestin∧∧/△△△△△△or∧∧∧∧∧∧/△△configuration.This cage with a cavity volume of 520˚A3 can bind anthracene,phenanthrene,and pyrene to form 1:1 host-vip complexes,while the bigger triphenylene,chrysene,perylene,and coronene cannot be encapsulated.The binding constant Ka of pyrene is about 1.110×10^(3)(mol/L)^(−1),which is more than an order of magnitude larger than that of anthracene and phenanthrene(111(mol/L)^(−1),277(mol/L)^(−1),respectively).X-ray structure studies reveal that the pyrene is located in the cavity and stabilized by multiple C–H…πinteractions.After separation from a mixture of PAHs,pyrene with>96.1%purity can be obtained.This work provides a useful method for the first time for the selective separation of pyrene from PAHs mixture by utilizing a metal-organic cage as the material,making it a useful tool for purifying and separating specific compounds from complex mixtures.
基金financial supports from National Natural Science Foundation of China(No.22204169)Gansu Natural Science Foundation(Nos.23JRRA619,21JR7RA076)Scientific and Technological Program of Chengguan District,Lanzhou(No.2023JSCX0037)。
文摘A novel amine-modified pillar[5]arene bonded porous silica adsorbent(DETA-P5S)was designed to be applied to dynamic CO_(2)adsorption and selective separation of CO_(2)over N_(2)and CH_(4)gases mixture.The results demonstrated that reasonable introduction of DETA into the BE-P5 bonded silica support has sig nificantly increased the adsorption capacity of CO_(2).The DETA-P5S has the optimal adsorption capacity of 9.1 mmol/g with 5 vol%CO_(2)at 40℃.The main reason of this increased capacity could be attributed to the enhanced CO_(2)diffusion into porous adsorbent for its better dispersion in the pores of amine pillar[5]arene cavity and active site of DETA.Furthermore,the dynamic saturation adsorption capacitie of DETA-P5S were 7.11(0.37)and 6.18(0.44)mmol/g for CO_(2)/N_(2)and CO_(2)/CH_(4),respectively,both the ga mixtures showed high separation selectivity.Simultaneously,the DETA-P5S can maintain outstanding CO_(2)adsorption capacity after fifteen regeneration cycles.Consequently,the designed DETA-P5S could serve a a promising adsorbent for CO_(2)capture and storage.
基金financially supported by the National Natural Science Foundation of China(No.21174124)K.C.Wong Magna Fund in Ningbo University
文摘Porous carbon membranes were favorably fabricated through the pyrolysis of polyacrylonitrile（PAN） precursors, which were prepared with a template-free technique-thermally induced phase separation. These carbon membranes possess hierarchical pores, including cellular macropores across the whole membranes and much small pores in the matrix as well as on the pore walls. Nitrogen adsorption indicates micropores（1.47 and 1.84 nm） and mesopores（2.21 nm） exist inside the carbon membranes, resulting in their specific surface area as large as 1062 m2/g. The carbon membranes were used to adsorb organic dyes（methyl orange, Congo red, and rhodamine B） from aqueous solutions based on their advantages of hierarchical pore structures and large specific surface area. It is particularly noteworthy that the membranes present a selective adsorption towards methyl orange, whose molecular size（1.2 nm） is smaller than those of Congo red（2.3 nm） and rhodamine B（1.8 nm）. This attractive result can be attributed to the steric structure matching between the molecular size and the pore size, rather than electrostatic attraction. Furthermore, the used carbon membranes can be easily regenerated by hydrochloric acid, and their recovery adsorption ratio maintains above 90% even in the third cycle. This work may provide a new route for carbon-based adsorbents with hierarchical pores via a template-free approach, which could be promisingly applied to selectively remove dye contaminants in aqueous effluents.
基金financially supported by the National Natural Science Foundation of China (22078132 and 22108103)Open Funding Project of the National Key Laboratory of Biochemical Engineering (2021KF-02)+3 种基金China Postdoctoral Science Foundation (2021M691301)Jiangsu Agricultural Independent Innovation Fund Project (CX(21)3079)Graduate Research Innovation Program of Jiangsu Province (KYCX20-3040)China Postdoctoral Science Foundation (2021M691301)。
文摘Molecularly imprinted polymers (MIPs) have great potential as adsorbents for selective adsorption and separation of nucleoside compounds,but effectively enhancing the affinity of recognition sites by adjusting the forces between template molecules and functional monomers remains an important challenge.In this work,a surface imprinting strategy was used to construct bowl-shaped molecularly imprinted composite sorbents (BHPN@MIPs) based on polydopamine (PDA) particles and have achieved selective separation and purification of 2'-deoxyadenosine (dA).Where by the base complementary pairing interaction of the combined template molecule d A and the pyrimidine functional monomer can enhance the preassembly force,and the hydrophilic bowl-shaped PDA can provide a larger storage space contact efficiency of d A in the test solution,causing the site utilization much higher and improving the kinetic adsorption performance.The equilibrium adsorption time and maximum adsorption capacity of60 min and 328.45μmol·g^(-1)were observed by static adsorption experiments,and the selectivity experimental results showed an imprinting factor IF of 1.30.After four adsorption–desorption cycles,the initial adsorption equilibrium adsorption capacity of BHPN@MIPs still retained 91.14%.By evaluating the selective adsorption of d A in spiked human serum solutions,BHPN@MIPs can be used to selectively enrich and analyze target d A in complex biological samples.
基金financial support from the National Natural Science Foundation of China (Nos. 21771191, 21571187)Taishan Scholar Foundation (No. ts201511019), the Applied Basic Research Projects of Qingdao (No. 16-5-1-95-jch)the Fundamental Research Funds for the Central Universities (Nos. 16CX05015A, 14CX02213A)
文摘A Co-based two-dimensional（2 D） microporous metal-organic frameworks, [Co2（TMTA）（DMF）2（H2O）2]·NO3-·DMF（UPC-32） has been synthesized based on 4,4’,4’’-（2,4,6-trimethylbenzene-1,3,5-triyl）tribenzoic acid（H3TMTA）. UPC-32 features a 2 D microporous framework exhibits high adsorption of H2（118.2 cm3/g, 1.05 wt%, at 77 K）, and adsorption heat（Qst） of CO2（34–46 k J/mol）. UPC-32 with narrow distance between layers（3.8 ？） exhibits high selectivity of C3H6/CH4（31.46） and C3H8/CH4（28.04） at298 K and 1 bar. It is the first 2 D Co-MOF that showed selective separation of C3 hydrocarbon from CH4.
基金We gratefully acknowledge the financial support from National Key Research and Development Project,China(2019YFA0708700)the National Natural Science Foundation of China(52222403,52074333)the Innovation Fund Project for graduate students of China University of Petroleum(East China)(22CX04049A).
文摘The membrane method based on adaptive wettability shows great advantages in oil-water separation.At present,researches focus on the excellent application performance of the membrane material,while the quantitative analysis of interactions in oil-water separation is rarely recognized.Herein,we constructed an adaptable wettability membrane with multiple polymer networks by polydopamine(PDA)and mussel-inspired amphiphilic polymer.Based on the Owens three-probe liquid method,the surface energy of the modified membrane was verified to meet the adaptive wettability conditions,with surface energies(γ-8)of 147.6 mJ m^(−2)(superhydrophilic/underwater superoleophobic)and 49.87 mJ m^(−2)(superhydrophobic/superoleophobic),respectively.The adhesion or repulsion of the membrane to the oil phase under different conditions during the separation process was quantified by the chemical probe AFM technique.In addition,the oil-water selective separation mechanism was further analyzed in a simplified membrane microchannel model.The results show that the different wetting produces capillary additional pressure in opposite directions,resulting in different energies to be overcome when the oil or water passes through the microchannels,thus achieving selective separation.
