Metal ion-imprintedly crosslinked chitosan resin 1 and resin 2 were prepared by theuse of Cu2+ and Ni2+ as template ions and glutaraldehyde as crosslinking agent, respectively.Through investigation on the adsorption c...Metal ion-imprintedly crosslinked chitosan resin 1 and resin 2 were prepared by theuse of Cu2+ and Ni2+ as template ions and glutaraldehyde as crosslinking agent, respectively.Through investigation on the adsorption capacities and binding constants for Cu2+, Ni2+andCo2+ ions on chitosan resins, resin 1 and resin 2 exhibit the adsorption selectivity for themixture solution of 1:1 Cu2+ and Ni2+ ions. The adsorption selectivity of metal ion-imprintedresins for their template ions is much higher than that of uncrosslinked chitosan resin.展开更多
Both bottle-point and column-feeding experi-ments involving different solutes and sorbents were carried out to investigate the adsorption selectivity and separation performance of salicylic acid and 5-sulfosalicylic a...Both bottle-point and column-feeding experi-ments involving different solutes and sorbents were carried out to investigate the adsorption selectivity and separation performance of salicylic acid and 5-sulfosalicylic acid.Their adsorption isotherms onto such hypercrosslinked polymeric adsorbents as NDA-100 and NDA-99 could be well described by the Freundlich equations whose characteristics describe extrathermic and favorable adsorption processes.The adsorp-tion towards NDA-100 mainly depended on the p-p interac-tion,while that towards NDA-99 was extremely influenced by the static-electric interaction.Additionally,the adsorptive capacity of salicylic acid on NDA-99 decreased while it increased on NDA-100 with the presence of 5-sulfosalicylic acid in the adsorptive environment as the competitive component.Comparatively,the adsorption capacity of 5-sulfosalicylic acid decreased on both resins with salicylic acid as the competitive component.In fact,the difference in the interaction between adsorbent and adsorbate resulted in the straight antagonism on the effective adsorption sites on the adsorbent.In conclusion,the adsorption selectivity of salicylic acid onto NDA-100 was obviously larger than that onto NDA-99 with the existence of 5-sulfosalicylic acid in the adsorptive environment.A satisfactory separation and recovery of tested solutes in aqueous phase could be foresee-ably achieved by the sequencing adsorption technique involving NDA-100 as well as NDA-99.展开更多
In this work,a novel composite material based on β-cyclodextrin-immobilized sodium alginate aerogel(β-CD/NaAlg) was developed utilizing cross-linker of epichlorohydrin and applied as an adsorbent to remove tetracycl...In this work,a novel composite material based on β-cyclodextrin-immobilized sodium alginate aerogel(β-CD/NaAlg) was developed utilizing cross-linker of epichlorohydrin and applied as an adsorbent to remove tetracycline antibiotics from reclaimed wastewater.A series of characterizations were utilized to confirm the successful synthesis of the adsorbent and this β-CD/NaAlg presented a three-dimensional network at the nanoscale or microscale.Under optimal conditions(pH=4,t=8 h,β-CD:NaAlg=9,adsorbent dosage = 1.5 g·L-1),the maximum removal rate of β-CD/NaAlg to tetracycline was 70%.The adsorption behavior of tetracycline on β-CD/NaAlg conformed to the Freundlich isotherm model(R2=0.9977) and the pseudo-second-order kinetic model(R^(2)=0.9993).Moreover,the adsorbent still removed 55.3% of tetracycline after five cycles.Specially,the adsorbent was integrated with ultrafiltration to adsorb tetracycline antibiotics from simulated reclaimed wastewater,and the removal rate of tetracycline reached 78.9% within 2 h.The existence of Cr(Ⅵ) had a negligible impact on tetracycline removal,while the presence of humic acid exhibited a promoting effect.The possible adsorption mechanisms were also elucidated through X-ray photoelectron spectroscopy and density functional theory analysis.In summary,β-CD/NaAlg represents an environmentally friendly,efficient,and sustainable adsorbent for removing tetracycline antibiotics from reclaimed water.展开更多
A novel porous coordination polymer,iron naphthalenedicarboxylate Fe(OH)(1,4-NDC)·2H2O is hydrothermally synthesized by the reaction of FeSO4·7H2O and 1,4-naphthalenedicarboxylic acid(1,4-H2NDC) at 150...A novel porous coordination polymer,iron naphthalenedicarboxylate Fe(OH)(1,4-NDC)·2H2O is hydrothermally synthesized by the reaction of FeSO4·7H2O and 1,4-naphthalenedicarboxylic acid(1,4-H2NDC) at 150℃.The compound crystallizes in a tetragonal space group P42/nmc:a=2.1447(4) nm,c=0.68849(14) nm,V=3.1669(11) nm3,Z=8,R=0.0845,wR=0.1829.The crystal structure exhibits a three-dimensional framework which is composed of infinite chains of corner-sharing octahedral Fe(OH)2O4 with 1,4-NDC ligands forming two types of channels with square-shaped cross-sections.The large channels present a cross-section of 0.76 nm×0.76 nm,while the small channels are about 0.30 nm×0.30 nm.No structural transformation occurs after removing the guest water molecules,while a robust structure generates with permanent porosity.The adsorption measurements show that the anhydrous sample of the compound can adsorb CO2 into its pores.The adsorption isotherms for methanol,acetone,tetrahydrofuran and benzene are also measured.展开更多
The adsorption behavior of CO_2, CH_4 and their mixtures in bituminous coal was investigated in this study. First, a bituminous coal model was built through molecular dynamic(MD) simulations, and it was confirmed to b...The adsorption behavior of CO_2, CH_4 and their mixtures in bituminous coal was investigated in this study. First, a bituminous coal model was built through molecular dynamic(MD) simulations, and it was confirmed to be reasonable by comparing the simulated results with the experimental data. Grand Canonical Monte Carlo(GCMC)simulations were then carried out to investigate the single and binary component adsorption of CO_2 and CH_4with the built bituminous coal model. For the single component adsorption, the isosteric heat of CO_2 adsorption is greater than that of CH_4 adsorption. CO_2 also exhibits stronger electrostatic interactions with the heteroatom groups in the bituminous coal model compared with CH_4, which can account for the larger adsorption capacity of CO_2 in the bituminous coal model. In the case of binary adsorption of CO_2 and CH_4mixtures, CO_2 exhibits the preferential adsorption compared with CH_4 under the studied conditions. The adsorption selectivity of CO_2 exhibited obvious change with increasing pressure. At lower pressure, the adsorption selectivity of CO_2 shows a rapid decrease with increasing the temperature, whereas it becomes insensitive to temperature at higher pressure. Additionally, the adsorption selectivity of CO_2 decreases gradually with the increase of the bulk CO_2 mole fraction and the depth of CO_2 injection site.展开更多
A novel,porous and doubly interpenetrated MOF(FJU-29) was synthesized and characterized by FT-IR,TGA and X-ray single-crystal/powder diffraction.FJU-29 crystallizes in monoclinic,space group C2/c with a = 22.2890(7...A novel,porous and doubly interpenetrated MOF(FJU-29) was synthesized and characterized by FT-IR,TGA and X-ray single-crystal/powder diffraction.FJU-29 crystallizes in monoclinic,space group C2/c with a = 22.2890(7),b = 10.9175(2),c = 21.5601(7) ?,β = 112.908(4)o,V = 4832.7(3) ?~3,Z = 8,Mr = 450.26,D_c = 1.238 g/cm^3,F(000) = 1832,μ(CuKα) = 5.885 mm^(-1),R = 0.0585 and wR = 0.1544 for 4789 observed reflections(I 〉 2s(I)),and R = 0.0726 and wR = 0.1627 for all data.FJU-29 possesses paddle-wheel {Co_2(COO)_4} clusters bridged by bi-pyrazolate naphthalene diimide ligands(H_2NDI) and H_2BDC to from a 3D framework with a pcu-topology.The desolvated FJU-29a shows the BET surface area of 560.44 m^2·g^(-1) accompanies with discriminating uptakes in CO_2 and N_2.The adsorption selectivity determined by ideal adsorbed solution theory(IAST) indicated that FJU-29 a has high CO_2/N_2(18/85) selectivity(75.5) at 296 K and 100 kPa.The relatively high selectivity further implies that FJU-29 a is a potential material for practical flue gas purification.展开更多
The adsorption of aniline, N-methylaniline and N,N-dimethylaniline onto carboxyl resin in Cu2+ form from water, ethanol and n-hexane have been studied. The results show that the adsorption affinities from n-hexane are...The adsorption of aniline, N-methylaniline and N,N-dimethylaniline onto carboxyl resin in Cu2+ form from water, ethanol and n-hexane have been studied. The results show that the adsorption affinities from n-hexane are higher than that from water, and nearly zero from ethanol. The separation factors for the adsorption of these three amines from mixed solution were also examined. The results of continuous column operations show that the breakthrough capacity of aniline from n-hexane reaches 90 mg/g dry resin in Cu2+ form, and the amines adsorbed can be stripped with anhydrous ethanol effectively. Adsorption onto carboxyl resin in Cu2+ form from non-aqueous medium and desorption with anhydrous eluant can overcome the run-off of Cu2+ from the resin, and would show potential advantages in the separation of some water-insoluble natural products.展开更多
Five microporous MOFs were synthesized and their static adsorption properties for light hydrocarbons were experimentally investigated at 298 K and 150 kPa.Among the five MOFs,HKUST-1 and Ni(bdc)(ted)0.5 exhibited much...Five microporous MOFs were synthesized and their static adsorption properties for light hydrocarbons were experimentally investigated at 298 K and 150 kPa.Among the five MOFs,HKUST-1 and Ni(bdc)(ted)0.5 exhibited much higher uptakes of ethane and propane than PCN-250,UiO-66,and ZIF-8.Breakthrough experiments were carried out at 298 K and atmospheric pressure on HKUST-1 and two commercially used adsorbents.HKUST-1 exhibited a much lower dynamic than static adsorption capacity.Moreover,HKUST-1 and the two traditional adsorbents could effectively separate binary(ethane/propane)and ternary(ethane/propane/toluene)mixtures.展开更多
A novel silica-supported tert-butyl 2-picolyamino-N-acetate chelating resin (Si-AMPY-1) was successfully synthesized and characterized by elemental analysis, FT-IR, SEM and 13 C CP/MAS NMR. The adsorption behaviors of...A novel silica-supported tert-butyl 2-picolyamino-N-acetate chelating resin (Si-AMPY-1) was successfully synthesized and characterized by elemental analysis, FT-IR, SEM and 13 C CP/MAS NMR. The adsorption behaviors of the Si-AMPY-1 resin for Cu(Ⅱ) and Ni(Ⅱ) were studied with batch and column methods. The batch experiments indicated that the Si-AMPY-1 resin adsorbed Ni(Ⅱ) mainly via physisorption, while adsorbed Cu(II) via chemisorption. The column dynamic breakthrough curves revealed thatthe Si-AMPY-1 resin can efficiently separate Cu(Ⅱ) from the simulated nickel electrolyte before the breakthrough point. Moreover, the concentration of Cu(Ⅱ) in the column effluent was decreased to be less than 3 mg/L within the first 43 BV (bed volumes), and the mass ratio of Cu/Ni was 21:1 in the saturated resin, which completely satisfied the industrial requirements of the nickel electrorefining process. Therefore, it was concluded that the Si-AMPY-1 resin can be a promising candidate for the deep removal of Cu(Ⅱ) from the nickel electrolyte.展开更多
Achieving efficient adsorption and desorption processes by controllably tuning the properties of adsorbents at different technical stages is extremely attractive.However,it is difficult for traditional adsorbents to r...Achieving efficient adsorption and desorption processes by controllably tuning the properties of adsorbents at different technical stages is extremely attractive.However,it is difficult for traditional adsorbents to reach the target because of their fixed active sites.Herein,we report on the fabrication of a smart adsorbent,which was achieved by introducing photoresponsive azobenzene derivatives with cis/trans isomers to Ce-doped mesoporous silica.These photoresponsive groups serve as “molecular switches”by sheltering and exposing active sites,leading to efficient adsorption and desorption.Ce is also doped to provide additional active sites in order to enhance the adsorption performance.The results show that the cis isomers effectively shelter the active sites,leading to the selective adsorption of methylene blue(MB)over brilliant blue(BB),while the trans isomers completely expose the active sites,resulting in the convenient release of the adsorbates.Both selective adsorption and efficient desorption can be realized controllably by these smart adsorbents through photostimulation.Moreover,the performance of the obtained materials is well maintained after five cycles.展开更多
Surface modification offers an alternative strategy to improve both ageing resistance and electrochemical performance of cathode materials for lithium-ion batteries.From the viewpoint of real application,surface modif...Surface modification offers an alternative strategy to improve both ageing resistance and electrochemical performance of cathode materials for lithium-ion batteries.From the viewpoint of real application,surface modification of the cathode materials should be designed with scientificity,effectiveness,low cost,less Li+leaching,and remained tap density.In this contribution,a selective adsorption-involved in-situ growth of polyaniline(PANI)nanoparticles on LiNi_(0.5)Mn_(0.3)Co_(0.2)O_(2)(NMC532)has been designed through a room-temperature-and-pressure chemical vapor deposition technique.The selective growth of PANTI on NMC532 is based on theoretical computation results that multivalent Ni,Mn,and Co are capable of specifically conjugating and activating aniline molecules and,hence,initiating in-situ oxidation polymerization.With only trace amount of aniline monomer,the resulting PANI nanoparticles-inlaid NMC532 microparticles can endure four-month ageing in ambient atmosphere and exhibit improved electrochemical performance at both room temperature and 55℃ compared with pristine NMC532.The improved electrochemical performance of NMC532/PANI is attributed to the enhanced structural stability of NMC532 and inhibited side reactions related to Li_(2)CO_(3) formation,PVDF degradation,electrolyte decomposition,and transition-metal dissolution,owing to PANI modification.展开更多
Silver‐modified semiconductor photocatalysts typically exhibit enhanced photocatalytic activitytoward the degradation of organic substances.In comparison,their hydrogen‐evolution rates arerelatively low owing to poo...Silver‐modified semiconductor photocatalysts typically exhibit enhanced photocatalytic activitytoward the degradation of organic substances.In comparison,their hydrogen‐evolution rates arerelatively low owing to poor interfacial catalytic reactions to producing hydrogen.In the presentstudy,thiocyanate anions(SCN–)as interfacial catalytic active sites were selectively adsorbed ontothe Ag surface of g‐C3N4/Ag photocatalyst to promote interfacial H2‐evolution reactions.The thiocyanate‐modified g‐C3N4/Ag(g‐C3N4/Ag‐SCN)photocatalysts were synthesized via photodepositionof metallic Ag on g‐C3N4and subsequent selective adsorption of SCN– ions on the Ag surface by animpregnation method.The resulting g‐C3N4/Ag‐SCN photocatalysts exhibited considerably higherphotocatalytic H2‐evolution activity than the g‐C3N4,g‐C3N4/Ag,and g‐C3N4/SCN photocatalysts.Furthermore,the g‐C3N4/Ag‐SCN photocatalyst displayed the highest H2‐evolution rate(3.9μmolh?1)when the concentration of the SCN– ions was adjusted to0.3mmol L?1.The H2‐evolution rateobtained was higher than those of g‐C3N4(0.15μmol h?1)and g‐C3N4/Ag(0.71μmol h?1).Consideringthe enhanced performance of g‐C3N4/Ag upon minimal addition of SCN– ions,a synergistic effectof metallic Ag and SCN– ions is proposed―the Ag nanoparticles act as an effective electron‐transfermediator for the steady capture and rapid transportation of photogenerated electrons,while theadsorbed SCN– ions serve as an interfacial active site to effectively absorb protons from solution andpromote rapid interfacial H2‐evolution reactions.Considering the present facile synthesis and itshigh efficacy,the present work may provide new insights into preparing high‐performance photocatalytic materials展开更多
Rare earth elements(REE)are strategic resources and the recycling of REE in alternative resources is urgent and gets increasingly attention.However,the separation of REE in these alternative resources is still a chall...Rare earth elements(REE)are strategic resources and the recycling of REE in alternative resources is urgent and gets increasingly attention.However,the separation of REE in these alternative resources is still a challenge due to the low concentration of REE and multi coexisted ions in acidic system.In this study,the species distribution of REE within the pH 0-8.0 was calculated.The SBA-15 originated from coal fly ash was modified by two steps with(3-aminopropyl)triethoxysilane(APTES)and diethylenetriaminepentaacetic dianhydride(DTPADA)to obtain DTPADA-SBA-15 adsorbent,which was applied to the selective adsorption of REE.The results showed that DTPADA-SBA-15 possessed excellent adsorption performance on the selective adsorption of REE,including Eu,Gd,Tb,Nd and Sm,in acidic solution(pH 2)with multi competing ions.The FT-IR and Zeta potential characterization verified that the chemical adsorption through the coordination of O in DTPADA-SBA-15 with REE was dominant at lower pH value.The study of adsorption kinetics indicated that the adsorption of rare earth metal ions followed pseudosecond-order kinetic,of which the adsorption process followed the Langmuir isotherm model.展开更多
The AgBr powder was prepared by a hydrothermal method via a reaction of AgNO3 with hexadecyltrimethy ammonium bromide(CTAB),namely,CTAB-assisted synthesis method.The selective-adsorption ability of the AgBr samples ...The AgBr powder was prepared by a hydrothermal method via a reaction of AgNO3 with hexadecyltrimethy ammonium bromide(CTAB),namely,CTAB-assisted synthesis method.The selective-adsorption ability of the AgBr samples for the MO was evaluated in a MO and Rhodamine B mixed solution via ultraviolet-visible spectra.Compared with the AgBr sample prepared from NaBr solution,it was found that the AgBr powder synthesized by CTAB-assisted method exhibited high selective-adsorption performance for the MO in the MO-RhB mixed system.After aged for 60 min,the MO could be efficiently removed by CTAB-assisted AgBr powder.Considering the potential wide applications of the selective adsorption,the CTAB-assisted AgBr provides a new and efficient method for the removal of various dyes and is possible to be widely used in industries.展开更多
A novel biosorbent was synthesized by grafting bisthiourea(BTU)on a silk sericin(SS)matrix.This biosorbent was denoted as BTU-SS and characterized by Fourier transform infrared spectroscopy(FTIR),zeta potential measur...A novel biosorbent was synthesized by grafting bisthiourea(BTU)on a silk sericin(SS)matrix.This biosorbent was denoted as BTU-SS and characterized by Fourier transform infrared spectroscopy(FTIR),zeta potential measurements,elemental analysis,and X-ray photoelectron spectroscopy(XPS).As revealed by the adsorption experiments,both BTU-SS and SS showed low affinity towards coexisting base metallic ions in Ag(I)-Cu(II)-Zn(II)-Ni(II)-Pb(II)electronic waste leachate mixtures,while their adsorption capacities towards Ag(I)reached 30.5 and 10.4 mg∙g-1 at a pH of 5.0,respectively.BTU-SS showed higher selectivity towards Ag(I)than SS,as revealed by the Ag(I)partition coefficients between the biosorbents and the leachate(16634.6 and 403.3,respectively).As further demonstrated by column experiments,BTU-SS allowed the separation of Ag(I)from an electronic waste leachate.Thermodynamic studies showed that the adsorption of Ag(I)was exothermic and spontaneous,while adsorption kinetic experiments revealed that chemisorption dominated the adsorption process with activation energies of 47.67 and 53.27 kJ∙mol-1 for BTU-SS and SS,respectively.FTIR and XPS analyses of fresh and Ag(I)-loaded BTU-SS further revealed an adsorption mechanism mainly involving electrostatic and coordination interactions.展开更多
Imprinted polymers were prepared for selective removal of Cu(Ⅱ) ions from metal solutions. Three ion-imprinted polymers were synthesized with methacrylic acid (MAA), acrylamide (AA) and N,N'-methylenebisacryla...Imprinted polymers were prepared for selective removal of Cu(Ⅱ) ions from metal solutions. Three ion-imprinted polymers were synthesized with methacrylic acid (MAA), acrylamide (AA) and N,N'-methylenebisacrylamide (MBAA) respectively as the functional monomers, ethleneglycoldimethacrylate (EGDMA) as the cross-linking agent, 2,2'- azobisisobutyronitrile (AIBN) as the initiator and Cu (Ⅱ) ion as the imprint ion. The template Cu (Ⅱ) ion was removed from the polymer by leaching with a liquid of a 1:1 volumetric ratio of HCl to ethylenediaminetetraacetic acid (EDTA). The capacity and selectivity of Cu(Ⅱ) ion adsorption were investigated with the three imprinted polymers and their non-imprinted counterparts. The polymers have a maximum adsorption capacity at pH 7.0. The isotherm of their batch adsorption of Cu(Ⅱ) ions shows a Langmuir adsorption pattern. Imprinted polymers all have a much higher capacity and higher selectivity of Cu(Ⅱ) adsorption than nonimprinted ones. MAA polymer benefits the most from imprinting. Imprinted MAA polymer has the highest selectivity when used to rebind Cu (Ⅱ) ion from an aqueous solution in the presence of other metal ions. Ion imprinting can be a promising technique of preparing selective adsorbents to separate and preconcentrate metal in a medium of multiple competitive metal ions through solid phase extraction (SPE).展开更多
To achieve efficient flotation separation of brucite and calcite,flotation separation experiments were conducted on two minerals using dodecylamine(DDA)as the collector and potassium dihydrogen phosphate(PDP)as the re...To achieve efficient flotation separation of brucite and calcite,flotation separation experiments were conducted on two minerals using dodecylamine(DDA)as the collector and potassium dihydrogen phosphate(PDP)as the regulator.The action mechanism of DDA and PDP was explored through contact angle measurement,zeta potential detection,solution chemistry calculation,FTIR analysis,and XPS detection.The flotation results showed that when DDA dosage was 35 mg/L and PDP dosage was 40 mg/L,the maximum floating difference between brucite and calcite was 79.81%,and the selectivity separation index was 6.46.The detection analysis showed that the main dissolved component HPO_(4)^(2−)of PDP is selectively strongly adsorbed on the Ca site on the surface of calcite,promoting the adsorption of the main dissolved component RNH_(3)^(+)of DDA on calcite surface,while brucite is basically not affected by PDP.Therefore,PDP is an effective regulator for the reverse flotation separation of brucite and calcite in DDA system.展开更多
As a cornerstone of the national economy,the iron and steel industry generates a significant amount of sintering dust containing both valuable lead resources and deleterious elements.Flotation is a promising technique...As a cornerstone of the national economy,the iron and steel industry generates a significant amount of sintering dust containing both valuable lead resources and deleterious elements.Flotation is a promising technique for lead recovery from sintering dust,but efficient separation from Fe_(2)O_(3) is still challenging.This study investigated the cooperative effect of sodium lauryl sulfate(SLS,C_(12)H_(25)SO_(4)Na)and sodium pyrophosphate(SPP,Na_(4)P_(2)O_(7))on the selective flotation of lead oxide minerals(PbOHCl and PbSO_(4))from hematite(Fe_(2)O_(3)).Optimal flotation conditions were first identified,resulting in high recovery of lead oxide minerals while inhibiting Fe_(2)O_(3) flotation.Zeta potential measurements,Fourier transform infrared spectroscopy(FT-IR)analysis,adsorption capacity analysis,and X-ray photoelectron spectroscopy(XPS)studies offer insights into the adsorption behaviors of the reagents on mineral surfaces,revealing strong adsorption of SLS on PbOHCl and PbSO_(4) surfaces and remarkable adsorption of SPP on Fe_(2)O_(3).The proposed model of reagent adsorption on mineral surfaces illustrates the selective adsorption behavior,highlighting the pivotal role of reagent adsorption in the separation process.These findings contribute to the efficient and environmentally friendly utilization of iron ore sintering dust for lead recovery,paving the way for sustainable resource management in the iron and steel industry.展开更多
Inhibitors are important for flotation separation of quartz and feldspar.In this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral pulp.Selective inhibition of the combined inhi...Inhibitors are important for flotation separation of quartz and feldspar.In this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral pulp.Selective inhibition of the combined inhibitor was assessed by micro-flotation experiments.And a series of detection methods were used to detect differences in the surface properties of feldspars and quartz after flotation reagents and put forward the synergistic strengthening mechanism.The outcomes were pointed out that pre-mixing combined inhibitors were more effective than the addition of Ca^(2+)and SS in sequence under the optimal proportion of 1:5.A concentrate from artificial mixed minerals that was characterized by a high quartz grade and a high recovery was acquired,and was found to be 90.70wt% and 83.70%,respectively.It was demonstrated that the combined inhibitor selectively prevented the action of the collector and feldspar from Fourier-transform infrared(FT-IR)and adsorption capacity tests.The results of X-ray photoelectron spectroscopy(XPS)indicated that Ca^(2+)directly interacts with the surface of quartz to increase the adsorption of collectors.In contrast,the chemistry property of Al on the feldspar surface was altered by combined inhibitor due to Na^(+)and Ca^(2+)taking the place of K^(+),resulting in the composite inhibitor forms a hydrophilic structure,which prevents the adsorption of the collector on the surface of feldspar by interacting with the Al active site.The combination of Ca^(2+)and SS synergically strengthens the difference of collecting property between quartz and feldspar by collector,thus achieving the effect of efficient separation.A new strategy for flotation to separate quartz from feldspar in near-neutral pulp was provided.展开更多
Adsorption process is considered to be the most promising alternative for the CO_(2) capture to the traditional energy-intensive amine absorption process,and the development of feasible and efficient CO_(2) adsorbents...Adsorption process is considered to be the most promising alternative for the CO_(2) capture to the traditional energy-intensive amine absorption process,and the development of feasible and efficient CO_(2) adsorbents is still a challenge.In this work,the NiO@USY(ultrastable Y)composites with different NiO loadings were prepared for the CO_(2) adsorption using Ni(NO_(3))_(2) as the precursor.The composites were characterized by X-ray photoelectron spectroscopy,X-ray diffraction,nitrogen adsorption–desorption test,scanning electron microscopy analysis,and thermogravimetric analysis,and were evaluated for the CO_(2) adsorption capacity,CO_(2)/N2 adsorption selectivity and CO_(2) cycle adsorption capacity.The characterization results show that after the activation at 423 K,the Ni(NO_(3))_(2) species were well dispersed into the surface of zeolite USY,and after the further activation at 823 K,Ni(NO_(3))_(2) could be converted into highly dispersed NiO.The adsorption results show that the presence of the active component NiO plays an important role in improving the CO_(2) adsorption performance,and the NiO@USY composite with a NiO loading of 1.5 mmol·g^(-1) USY support displays a high adsorption capacity and adsorption selectivity for CO_(2),and shows a good cycle stability.In addition,the Clausius–Clapeyron equation was used to evaluate the isosteric heat of adsorption of CO_(2) on the NiO(1.5)@USY composite,and the heat of adsorption was 17.39–38.34 kJ·mol^(-1).展开更多
文摘Metal ion-imprintedly crosslinked chitosan resin 1 and resin 2 were prepared by theuse of Cu2+ and Ni2+ as template ions and glutaraldehyde as crosslinking agent, respectively.Through investigation on the adsorption capacities and binding constants for Cu2+, Ni2+andCo2+ ions on chitosan resins, resin 1 and resin 2 exhibit the adsorption selectivity for themixture solution of 1:1 Cu2+ and Ni2+ ions. The adsorption selectivity of metal ion-imprintedresins for their template ions is much higher than that of uncrosslinked chitosan resin.
基金The work was supported by the Opening Fund of Key Laboratory of Environmental Engineering of Jiangsu Province,China(Grant No.KF0502)by the Opening Fund of Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection(Grant No.JLCBE05005).
文摘Both bottle-point and column-feeding experi-ments involving different solutes and sorbents were carried out to investigate the adsorption selectivity and separation performance of salicylic acid and 5-sulfosalicylic acid.Their adsorption isotherms onto such hypercrosslinked polymeric adsorbents as NDA-100 and NDA-99 could be well described by the Freundlich equations whose characteristics describe extrathermic and favorable adsorption processes.The adsorp-tion towards NDA-100 mainly depended on the p-p interac-tion,while that towards NDA-99 was extremely influenced by the static-electric interaction.Additionally,the adsorptive capacity of salicylic acid on NDA-99 decreased while it increased on NDA-100 with the presence of 5-sulfosalicylic acid in the adsorptive environment as the competitive component.Comparatively,the adsorption capacity of 5-sulfosalicylic acid decreased on both resins with salicylic acid as the competitive component.In fact,the difference in the interaction between adsorbent and adsorbate resulted in the straight antagonism on the effective adsorption sites on the adsorbent.In conclusion,the adsorption selectivity of salicylic acid onto NDA-100 was obviously larger than that onto NDA-99 with the existence of 5-sulfosalicylic acid in the adsorptive environment.A satisfactory separation and recovery of tested solutes in aqueous phase could be foresee-ably achieved by the sequencing adsorption technique involving NDA-100 as well as NDA-99.
基金supported by the National Key Research and Development Program of China(2022YFC3801101)National Natural Science Foundation of China(52170028)+1 种基金the State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(2023DX11)National Engineering Research Center for Safe Sludge Disposal and Resource Recovery(2021A003).
文摘In this work,a novel composite material based on β-cyclodextrin-immobilized sodium alginate aerogel(β-CD/NaAlg) was developed utilizing cross-linker of epichlorohydrin and applied as an adsorbent to remove tetracycline antibiotics from reclaimed wastewater.A series of characterizations were utilized to confirm the successful synthesis of the adsorbent and this β-CD/NaAlg presented a three-dimensional network at the nanoscale or microscale.Under optimal conditions(pH=4,t=8 h,β-CD:NaAlg=9,adsorbent dosage = 1.5 g·L-1),the maximum removal rate of β-CD/NaAlg to tetracycline was 70%.The adsorption behavior of tetracycline on β-CD/NaAlg conformed to the Freundlich isotherm model(R2=0.9977) and the pseudo-second-order kinetic model(R^(2)=0.9993).Moreover,the adsorbent still removed 55.3% of tetracycline after five cycles.Specially,the adsorbent was integrated with ultrafiltration to adsorb tetracycline antibiotics from simulated reclaimed wastewater,and the removal rate of tetracycline reached 78.9% within 2 h.The existence of Cr(Ⅵ) had a negligible impact on tetracycline removal,while the presence of humic acid exhibited a promoting effect.The possible adsorption mechanisms were also elucidated through X-ray photoelectron spectroscopy and density functional theory analysis.In summary,β-CD/NaAlg represents an environmentally friendly,efficient,and sustainable adsorbent for removing tetracycline antibiotics from reclaimed water.
基金The Natural Science Foundation of Jiangsu Province(No.BK2009262)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry
文摘A novel porous coordination polymer,iron naphthalenedicarboxylate Fe(OH)(1,4-NDC)·2H2O is hydrothermally synthesized by the reaction of FeSO4·7H2O and 1,4-naphthalenedicarboxylic acid(1,4-H2NDC) at 150℃.The compound crystallizes in a tetragonal space group P42/nmc:a=2.1447(4) nm,c=0.68849(14) nm,V=3.1669(11) nm3,Z=8,R=0.0845,wR=0.1829.The crystal structure exhibits a three-dimensional framework which is composed of infinite chains of corner-sharing octahedral Fe(OH)2O4 with 1,4-NDC ligands forming two types of channels with square-shaped cross-sections.The large channels present a cross-section of 0.76 nm×0.76 nm,while the small channels are about 0.30 nm×0.30 nm.No structural transformation occurs after removing the guest water molecules,while a robust structure generates with permanent porosity.The adsorption measurements show that the anhydrous sample of the compound can adsorb CO2 into its pores.The adsorption isotherms for methanol,acetone,tetrahydrofuran and benzene are also measured.
基金Supported by the CNPC Huabei Oilfield Science and Technology Development Project(HBYT-CYY-2014-JS-378,HBYT-CYY-2015-JS-47)
文摘The adsorption behavior of CO_2, CH_4 and their mixtures in bituminous coal was investigated in this study. First, a bituminous coal model was built through molecular dynamic(MD) simulations, and it was confirmed to be reasonable by comparing the simulated results with the experimental data. Grand Canonical Monte Carlo(GCMC)simulations were then carried out to investigate the single and binary component adsorption of CO_2 and CH_4with the built bituminous coal model. For the single component adsorption, the isosteric heat of CO_2 adsorption is greater than that of CH_4 adsorption. CO_2 also exhibits stronger electrostatic interactions with the heteroatom groups in the bituminous coal model compared with CH_4, which can account for the larger adsorption capacity of CO_2 in the bituminous coal model. In the case of binary adsorption of CO_2 and CH_4mixtures, CO_2 exhibits the preferential adsorption compared with CH_4 under the studied conditions. The adsorption selectivity of CO_2 exhibited obvious change with increasing pressure. At lower pressure, the adsorption selectivity of CO_2 shows a rapid decrease with increasing the temperature, whereas it becomes insensitive to temperature at higher pressure. Additionally, the adsorption selectivity of CO_2 decreases gradually with the increase of the bulk CO_2 mole fraction and the depth of CO_2 injection site.
基金Financially supported by the National Natural Science Foundation of China(21273033,21673039 and 21573042)
文摘A novel,porous and doubly interpenetrated MOF(FJU-29) was synthesized and characterized by FT-IR,TGA and X-ray single-crystal/powder diffraction.FJU-29 crystallizes in monoclinic,space group C2/c with a = 22.2890(7),b = 10.9175(2),c = 21.5601(7) ?,β = 112.908(4)o,V = 4832.7(3) ?~3,Z = 8,Mr = 450.26,D_c = 1.238 g/cm^3,F(000) = 1832,μ(CuKα) = 5.885 mm^(-1),R = 0.0585 and wR = 0.1544 for 4789 observed reflections(I 〉 2s(I)),and R = 0.0726 and wR = 0.1627 for all data.FJU-29 possesses paddle-wheel {Co_2(COO)_4} clusters bridged by bi-pyrazolate naphthalene diimide ligands(H_2NDI) and H_2BDC to from a 3D framework with a pcu-topology.The desolvated FJU-29a shows the BET surface area of 560.44 m^2·g^(-1) accompanies with discriminating uptakes in CO_2 and N_2.The adsorption selectivity determined by ideal adsorbed solution theory(IAST) indicated that FJU-29 a has high CO_2/N_2(18/85) selectivity(75.5) at 296 K and 100 kPa.The relatively high selectivity further implies that FJU-29 a is a potential material for practical flue gas purification.
基金This study was supported by National Natural Science Foundation (Grant No. 29974015)
文摘The adsorption of aniline, N-methylaniline and N,N-dimethylaniline onto carboxyl resin in Cu2+ form from water, ethanol and n-hexane have been studied. The results show that the adsorption affinities from n-hexane are higher than that from water, and nearly zero from ethanol. The separation factors for the adsorption of these three amines from mixed solution were also examined. The results of continuous column operations show that the breakthrough capacity of aniline from n-hexane reaches 90 mg/g dry resin in Cu2+ form, and the amines adsorbed can be stripped with anhydrous ethanol effectively. Adsorption onto carboxyl resin in Cu2+ form from non-aqueous medium and desorption with anhydrous eluant can overcome the run-off of Cu2+ from the resin, and would show potential advantages in the separation of some water-insoluble natural products.
基金supported by the National Natural Science Foundation of China(grant number:21701189).
文摘Five microporous MOFs were synthesized and their static adsorption properties for light hydrocarbons were experimentally investigated at 298 K and 150 kPa.Among the five MOFs,HKUST-1 and Ni(bdc)(ted)0.5 exhibited much higher uptakes of ethane and propane than PCN-250,UiO-66,and ZIF-8.Breakthrough experiments were carried out at 298 K and atmospheric pressure on HKUST-1 and two commercially used adsorbents.HKUST-1 exhibited a much lower dynamic than static adsorption capacity.Moreover,HKUST-1 and the two traditional adsorbents could effectively separate binary(ethane/propane)and ternary(ethane/propane/toluene)mixtures.
基金Project (2014CB643401) supported by the National Basic Research Program of ChinaProjects (51134007,51474256) supported by the National Natural Science Foundation of ChinaProject (2016TP1007) supported by the Hunan Provincial Science and Technology Plan Project in China
文摘A novel silica-supported tert-butyl 2-picolyamino-N-acetate chelating resin (Si-AMPY-1) was successfully synthesized and characterized by elemental analysis, FT-IR, SEM and 13 C CP/MAS NMR. The adsorption behaviors of the Si-AMPY-1 resin for Cu(Ⅱ) and Ni(Ⅱ) were studied with batch and column methods. The batch experiments indicated that the Si-AMPY-1 resin adsorbed Ni(Ⅱ) mainly via physisorption, while adsorbed Cu(II) via chemisorption. The column dynamic breakthrough curves revealed thatthe Si-AMPY-1 resin can efficiently separate Cu(Ⅱ) from the simulated nickel electrolyte before the breakthrough point. Moreover, the concentration of Cu(Ⅱ) in the column effluent was decreased to be less than 3 mg/L within the first 43 BV (bed volumes), and the mass ratio of Cu/Ni was 21:1 in the saturated resin, which completely satisfied the industrial requirements of the nickel electrorefining process. Therefore, it was concluded that the Si-AMPY-1 resin can be a promising candidate for the deep removal of Cu(Ⅱ) from the nickel electrolyte.
基金This work was supported by the National Science Fund for Excellent Young Scholars(21722606)the National Natural Science Foundation of China(21676138,21878149,21808110,and 21576137)+1 种基金the China Postdoctoral Science Foundation(2018M632295)the Six Talent Plan(2016XCL031).
文摘Achieving efficient adsorption and desorption processes by controllably tuning the properties of adsorbents at different technical stages is extremely attractive.However,it is difficult for traditional adsorbents to reach the target because of their fixed active sites.Herein,we report on the fabrication of a smart adsorbent,which was achieved by introducing photoresponsive azobenzene derivatives with cis/trans isomers to Ce-doped mesoporous silica.These photoresponsive groups serve as “molecular switches”by sheltering and exposing active sites,leading to efficient adsorption and desorption.Ce is also doped to provide additional active sites in order to enhance the adsorption performance.The results show that the cis isomers effectively shelter the active sites,leading to the selective adsorption of methylene blue(MB)over brilliant blue(BB),while the trans isomers completely expose the active sites,resulting in the convenient release of the adsorbates.Both selective adsorption and efficient desorption can be realized controllably by these smart adsorbents through photostimulation.Moreover,the performance of the obtained materials is well maintained after five cycles.
基金financially supported by the Natural Science Foundation of Shandong Province(ZR2019MEM015 and ZR2017QB003)Young Taishan Scholar Program of Shandong Province(No.tsqn201909139)the Introduction and Cultivation Plan of Young Innovative Talents in Colleges and Universities of Shandong Province。
文摘Surface modification offers an alternative strategy to improve both ageing resistance and electrochemical performance of cathode materials for lithium-ion batteries.From the viewpoint of real application,surface modification of the cathode materials should be designed with scientificity,effectiveness,low cost,less Li+leaching,and remained tap density.In this contribution,a selective adsorption-involved in-situ growth of polyaniline(PANI)nanoparticles on LiNi_(0.5)Mn_(0.3)Co_(0.2)O_(2)(NMC532)has been designed through a room-temperature-and-pressure chemical vapor deposition technique.The selective growth of PANTI on NMC532 is based on theoretical computation results that multivalent Ni,Mn,and Co are capable of specifically conjugating and activating aniline molecules and,hence,initiating in-situ oxidation polymerization.With only trace amount of aniline monomer,the resulting PANI nanoparticles-inlaid NMC532 microparticles can endure four-month ageing in ambient atmosphere and exhibit improved electrochemical performance at both room temperature and 55℃ compared with pristine NMC532.The improved electrochemical performance of NMC532/PANI is attributed to the enhanced structural stability of NMC532 and inhibited side reactions related to Li_(2)CO_(3) formation,PVDF degradation,electrolyte decomposition,and transition-metal dissolution,owing to PANI modification.
基金supported by the National Natural Science Foundation of China(51472192,21477094,21771142)the Fundamental Research Funds for the Central Universities(WUT 2017IB002)~~
文摘Silver‐modified semiconductor photocatalysts typically exhibit enhanced photocatalytic activitytoward the degradation of organic substances.In comparison,their hydrogen‐evolution rates arerelatively low owing to poor interfacial catalytic reactions to producing hydrogen.In the presentstudy,thiocyanate anions(SCN–)as interfacial catalytic active sites were selectively adsorbed ontothe Ag surface of g‐C3N4/Ag photocatalyst to promote interfacial H2‐evolution reactions.The thiocyanate‐modified g‐C3N4/Ag(g‐C3N4/Ag‐SCN)photocatalysts were synthesized via photodepositionof metallic Ag on g‐C3N4and subsequent selective adsorption of SCN– ions on the Ag surface by animpregnation method.The resulting g‐C3N4/Ag‐SCN photocatalysts exhibited considerably higherphotocatalytic H2‐evolution activity than the g‐C3N4,g‐C3N4/Ag,and g‐C3N4/SCN photocatalysts.Furthermore,the g‐C3N4/Ag‐SCN photocatalyst displayed the highest H2‐evolution rate(3.9μmolh?1)when the concentration of the SCN– ions was adjusted to0.3mmol L?1.The H2‐evolution rateobtained was higher than those of g‐C3N4(0.15μmol h?1)and g‐C3N4/Ag(0.71μmol h?1).Consideringthe enhanced performance of g‐C3N4/Ag upon minimal addition of SCN– ions,a synergistic effectof metallic Ag and SCN– ions is proposed―the Ag nanoparticles act as an effective electron‐transfermediator for the steady capture and rapid transportation of photogenerated electrons,while theadsorbed SCN– ions serve as an interfacial active site to effectively absorb protons from solution andpromote rapid interfacial H2‐evolution reactions.Considering the present facile synthesis and itshigh efficacy,the present work may provide new insights into preparing high‐performance photocatalytic materials
基金the National Natural Science Foundation of China(U1810205)Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi Province(2020L0022)Key Research and Development Program of Shanxi Province(201903D311006).
文摘Rare earth elements(REE)are strategic resources and the recycling of REE in alternative resources is urgent and gets increasingly attention.However,the separation of REE in these alternative resources is still a challenge due to the low concentration of REE and multi coexisted ions in acidic system.In this study,the species distribution of REE within the pH 0-8.0 was calculated.The SBA-15 originated from coal fly ash was modified by two steps with(3-aminopropyl)triethoxysilane(APTES)and diethylenetriaminepentaacetic dianhydride(DTPADA)to obtain DTPADA-SBA-15 adsorbent,which was applied to the selective adsorption of REE.The results showed that DTPADA-SBA-15 possessed excellent adsorption performance on the selective adsorption of REE,including Eu,Gd,Tb,Nd and Sm,in acidic solution(pH 2)with multi competing ions.The FT-IR and Zeta potential characterization verified that the chemical adsorption through the coordination of O in DTPADA-SBA-15 with REE was dominant at lower pH value.The study of adsorption kinetics indicated that the adsorption of rare earth metal ions followed pseudosecond-order kinetic,of which the adsorption process followed the Langmuir isotherm model.
基金Funded by the National Natural Science Foundation of China (No.20803055)the Fundamental Research Funds for the Central Universities(Nos.2011-1a-39 and 2011-1a-16)
文摘The AgBr powder was prepared by a hydrothermal method via a reaction of AgNO3 with hexadecyltrimethy ammonium bromide(CTAB),namely,CTAB-assisted synthesis method.The selective-adsorption ability of the AgBr samples for the MO was evaluated in a MO and Rhodamine B mixed solution via ultraviolet-visible spectra.Compared with the AgBr sample prepared from NaBr solution,it was found that the AgBr powder synthesized by CTAB-assisted method exhibited high selective-adsorption performance for the MO in the MO-RhB mixed system.After aged for 60 min,the MO could be efficiently removed by CTAB-assisted AgBr powder.Considering the potential wide applications of the selective adsorption,the CTAB-assisted AgBr provides a new and efficient method for the removal of various dyes and is possible to be widely used in industries.
基金This work was supported by the Natural Science Foundation of Education Department of Shaanxi Provincial Government(2013JK0873).
文摘A novel biosorbent was synthesized by grafting bisthiourea(BTU)on a silk sericin(SS)matrix.This biosorbent was denoted as BTU-SS and characterized by Fourier transform infrared spectroscopy(FTIR),zeta potential measurements,elemental analysis,and X-ray photoelectron spectroscopy(XPS).As revealed by the adsorption experiments,both BTU-SS and SS showed low affinity towards coexisting base metallic ions in Ag(I)-Cu(II)-Zn(II)-Ni(II)-Pb(II)electronic waste leachate mixtures,while their adsorption capacities towards Ag(I)reached 30.5 and 10.4 mg∙g-1 at a pH of 5.0,respectively.BTU-SS showed higher selectivity towards Ag(I)than SS,as revealed by the Ag(I)partition coefficients between the biosorbents and the leachate(16634.6 and 403.3,respectively).As further demonstrated by column experiments,BTU-SS allowed the separation of Ag(I)from an electronic waste leachate.Thermodynamic studies showed that the adsorption of Ag(I)was exothermic and spontaneous,while adsorption kinetic experiments revealed that chemisorption dominated the adsorption process with activation energies of 47.67 and 53.27 kJ∙mol-1 for BTU-SS and SS,respectively.FTIR and XPS analyses of fresh and Ag(I)-loaded BTU-SS further revealed an adsorption mechanism mainly involving electrostatic and coordination interactions.
基金the Natural Science Foundation of Hunan Province (No. 06JJ4117).
文摘Imprinted polymers were prepared for selective removal of Cu(Ⅱ) ions from metal solutions. Three ion-imprinted polymers were synthesized with methacrylic acid (MAA), acrylamide (AA) and N,N'-methylenebisacrylamide (MBAA) respectively as the functional monomers, ethleneglycoldimethacrylate (EGDMA) as the cross-linking agent, 2,2'- azobisisobutyronitrile (AIBN) as the initiator and Cu (Ⅱ) ion as the imprint ion. The template Cu (Ⅱ) ion was removed from the polymer by leaching with a liquid of a 1:1 volumetric ratio of HCl to ethylenediaminetetraacetic acid (EDTA). The capacity and selectivity of Cu(Ⅱ) ion adsorption were investigated with the three imprinted polymers and their non-imprinted counterparts. The polymers have a maximum adsorption capacity at pH 7.0. The isotherm of their batch adsorption of Cu(Ⅱ) ions shows a Langmuir adsorption pattern. Imprinted polymers all have a much higher capacity and higher selectivity of Cu(Ⅱ) adsorption than nonimprinted ones. MAA polymer benefits the most from imprinting. Imprinted MAA polymer has the highest selectivity when used to rebind Cu (Ⅱ) ion from an aqueous solution in the presence of other metal ions. Ion imprinting can be a promising technique of preparing selective adsorbents to separate and preconcentrate metal in a medium of multiple competitive metal ions through solid phase extraction (SPE).
基金the General Program of the National Natural Science Foundation of China(Nos.51974064,52174239)the National Key R&D Program of China(No.2021YFC2902400)the Outstanding Postdoctoral Program of Jiangsu Province,China(No.2022ZB521).
文摘To achieve efficient flotation separation of brucite and calcite,flotation separation experiments were conducted on two minerals using dodecylamine(DDA)as the collector and potassium dihydrogen phosphate(PDP)as the regulator.The action mechanism of DDA and PDP was explored through contact angle measurement,zeta potential detection,solution chemistry calculation,FTIR analysis,and XPS detection.The flotation results showed that when DDA dosage was 35 mg/L and PDP dosage was 40 mg/L,the maximum floating difference between brucite and calcite was 79.81%,and the selectivity separation index was 6.46.The detection analysis showed that the main dissolved component HPO_(4)^(2−)of PDP is selectively strongly adsorbed on the Ca site on the surface of calcite,promoting the adsorption of the main dissolved component RNH_(3)^(+)of DDA on calcite surface,while brucite is basically not affected by PDP.Therefore,PDP is an effective regulator for the reverse flotation separation of brucite and calcite in DDA system.
基金supported by the National Natural Science Foundation of China(Nos.52004335 and 52204298)the National Natural Science Foundation of Hunan Province,China(No.2023JJ20071)the Science and Technology Innovation Program of Hunan Province,China(No.2023RC3067).
文摘As a cornerstone of the national economy,the iron and steel industry generates a significant amount of sintering dust containing both valuable lead resources and deleterious elements.Flotation is a promising technique for lead recovery from sintering dust,but efficient separation from Fe_(2)O_(3) is still challenging.This study investigated the cooperative effect of sodium lauryl sulfate(SLS,C_(12)H_(25)SO_(4)Na)and sodium pyrophosphate(SPP,Na_(4)P_(2)O_(7))on the selective flotation of lead oxide minerals(PbOHCl and PbSO_(4))from hematite(Fe_(2)O_(3)).Optimal flotation conditions were first identified,resulting in high recovery of lead oxide minerals while inhibiting Fe_(2)O_(3) flotation.Zeta potential measurements,Fourier transform infrared spectroscopy(FT-IR)analysis,adsorption capacity analysis,and X-ray photoelectron spectroscopy(XPS)studies offer insights into the adsorption behaviors of the reagents on mineral surfaces,revealing strong adsorption of SLS on PbOHCl and PbSO_(4) surfaces and remarkable adsorption of SPP on Fe_(2)O_(3).The proposed model of reagent adsorption on mineral surfaces illustrates the selective adsorption behavior,highlighting the pivotal role of reagent adsorption in the separation process.These findings contribute to the efficient and environmentally friendly utilization of iron ore sintering dust for lead recovery,paving the way for sustainable resource management in the iron and steel industry.
基金the financial support from the National Key Research and Development Program of China(No.2018YFC1903403)Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001).
文摘Inhibitors are important for flotation separation of quartz and feldspar.In this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral pulp.Selective inhibition of the combined inhibitor was assessed by micro-flotation experiments.And a series of detection methods were used to detect differences in the surface properties of feldspars and quartz after flotation reagents and put forward the synergistic strengthening mechanism.The outcomes were pointed out that pre-mixing combined inhibitors were more effective than the addition of Ca^(2+)and SS in sequence under the optimal proportion of 1:5.A concentrate from artificial mixed minerals that was characterized by a high quartz grade and a high recovery was acquired,and was found to be 90.70wt% and 83.70%,respectively.It was demonstrated that the combined inhibitor selectively prevented the action of the collector and feldspar from Fourier-transform infrared(FT-IR)and adsorption capacity tests.The results of X-ray photoelectron spectroscopy(XPS)indicated that Ca^(2+)directly interacts with the surface of quartz to increase the adsorption of collectors.In contrast,the chemistry property of Al on the feldspar surface was altered by combined inhibitor due to Na^(+)and Ca^(2+)taking the place of K^(+),resulting in the composite inhibitor forms a hydrophilic structure,which prevents the adsorption of the collector on the surface of feldspar by interacting with the Al active site.The combination of Ca^(2+)and SS synergically strengthens the difference of collecting property between quartz and feldspar by collector,thus achieving the effect of efficient separation.A new strategy for flotation to separate quartz from feldspar in near-neutral pulp was provided.
基金This work was funded by the Qingdao Science and Technology Plan Application Foundation Research Project(19-6-2-28-cg).
文摘Adsorption process is considered to be the most promising alternative for the CO_(2) capture to the traditional energy-intensive amine absorption process,and the development of feasible and efficient CO_(2) adsorbents is still a challenge.In this work,the NiO@USY(ultrastable Y)composites with different NiO loadings were prepared for the CO_(2) adsorption using Ni(NO_(3))_(2) as the precursor.The composites were characterized by X-ray photoelectron spectroscopy,X-ray diffraction,nitrogen adsorption–desorption test,scanning electron microscopy analysis,and thermogravimetric analysis,and were evaluated for the CO_(2) adsorption capacity,CO_(2)/N2 adsorption selectivity and CO_(2) cycle adsorption capacity.The characterization results show that after the activation at 423 K,the Ni(NO_(3))_(2) species were well dispersed into the surface of zeolite USY,and after the further activation at 823 K,Ni(NO_(3))_(2) could be converted into highly dispersed NiO.The adsorption results show that the presence of the active component NiO plays an important role in improving the CO_(2) adsorption performance,and the NiO@USY composite with a NiO loading of 1.5 mmol·g^(-1) USY support displays a high adsorption capacity and adsorption selectivity for CO_(2),and shows a good cycle stability.In addition,the Clausius–Clapeyron equation was used to evaluate the isosteric heat of adsorption of CO_(2) on the NiO(1.5)@USY composite,and the heat of adsorption was 17.39–38.34 kJ·mol^(-1).