In this study we used the deep eutectic solvents (ionic liquids) to investigate the reaction between copper (II) with ethylene diamine (en). Two of the existing methods for analyzing spectrophotometric measurements ha...In this study we used the deep eutectic solvents (ionic liquids) to investigate the reaction between copper (II) with ethylene diamine (en). Two of the existing methods for analyzing spectrophotometric measurements have been applied for establishing, the stoichiometry and whenever possible, the stability constants of the chelates formed. The method of continuous variations was necessary to determine first whether, the metal ion and the ligand ethylene diamine form one or more than one chelate, when more than one chelate formed, the results obtained depend on the wavelength and for meaningful conclusions the wavelengths were carefully selected. The empirical formulae of the chelates were further substantiated by the molar ratio method. The effect of time and temperature on the formation and stability of these chelates in solution is also studied. The stability constants, K1 and K2 for the copper (II) chelates were calculated, though reliable, and are comparable to literature values.展开更多
Cu^(+)-doped alkali borosilicate glasses with different Na_(2)O contents were prepared by the melting method,and the effects of different R values(R=Na_(2)O/B_(2)O_(3))on the structure,ion presence state and luminesce...Cu^(+)-doped alkali borosilicate glasses with different Na_(2)O contents were prepared by the melting method,and the effects of different R values(R=Na_(2)O/B_(2)O_(3))on the structure,ion presence state and luminescence properties of Cu^(+)-doped alkali borosilicate glasses were investigated.The analysis by FT-IR and Raman spectroscopy shows that,with the increase of R value of the glass,the[BO_(3)]in the structure of Cu^(+)-doped alkali borosilicate glass transforms into[BO_(4)]and the number of non-bridging oxygen in the glass network appears to be slightly increased.The absorption spectra and EPR analysis reveal that the Cu^(+)content in the glass gradually decreases and the Cu^(2+)content gradually increases as the R value of the glass increases.XPS and PL tests further indicate that the transformation of the octahedral coordination structure of Cu^(+)to the octahedral coordination structure of Cu^(2+)and the cubic coordination structure of Cu^(+)occurs in the glass as the R value of the glass increases.This transformation can effectively reduce the concentration quenching phenomenon of Cu^(+)and improve the fluorescence luminescence intensity of the glass samples.Meanwhile,the samples were found to have luminescence tunability as well as good thermal stability.展开更多
This paper reports the results of spectral measurements and a theoretical analysis of the temporal and spatial evolution of laser-produced Cu plasma in vacuum in the range of 8–14 nm.The time dependence of the extrem...This paper reports the results of spectral measurements and a theoretical analysis of the temporal and spatial evolution of laser-produced Cu plasma in vacuum in the range of 8–14 nm.The time dependence of the extreme ultraviolet band spectrum at different positions near the target surface was obtained and found to be dominated by three broad-band features.The 3p and 3d excitations of Cu5+–Cu9+ions were calculated using the Hartree–Fock theory with configuration interactions.The characteristics of the spectral line distribution for the 3p–nd and 3d–nf transition arrays were analyzed.Based on the steady-state collisional radiation model and the normalized Boltzmann distribution,the complex spectral structure in the band of 13–14 nm is accurately explained through consistency comparisons and benchmarking between the experimental and theoretical simulation spectra,demonstrating that the structure mainly stems from the overlapping contribution of the 3d–4f and 3p–3d transition arrays for the Cu5+–Cu9+ions.These results may help in studying the radiation characteristics of isoelectronic series highly-charged ions involving the 3d excitation process.展开更多
Adsorption of Cu(II) and Co(II) from aqueous solutions on synthetic nano Fe3O4 has been studied. The effect of experimental parameters such as initial concentration of the metal ions, adsorbent dosage, contact time an...Adsorption of Cu(II) and Co(II) from aqueous solutions on synthetic nano Fe3O4 has been studied. The effect of experimental parameters such as initial concentration of the metal ions, adsorbent dosage, contact time and pH has been investigated. Optimum removal efficiency of Cu(II) ion was found to be 97.8% with the dose rate of 1.07 g/L in 60 minutes at pH = 5.5 and for Co(II) ion, it was found to be 99.2% with the dose rate of2.57 g/L in 10 minutes at pH = 5.4. The removal of Co(II) ions require only 10 minutes with the efficient removal of 99.2%, whereas Cu(II) ions require 60 minutes with the maximum removal of 97.8%. In order to understand the effective removal of Cu(II) and Co(II) ions on Fe3O4, room temperature magnetic measurement was carried out using Vibrational Spectrum Magnetometer (VSM), before and after adsorption with a maximum applied magnetic field of 20,000 G.展开更多
In this study, the ability of red alga (Palmaria palmata) and beer draff (brewery waste) for Cu(II) removal was investigated. The influence of factors, such as pH, initial copper concentrations, and contact time, were...In this study, the ability of red alga (Palmaria palmata) and beer draff (brewery waste) for Cu(II) removal was investigated. The influence of factors, such as pH, initial copper concentrations, and contact time, were also studied. Results showed the adsorption process was strongly dependent on the pH value and initial concentration. The optimum pH value was in the range of 5-6. The Langmuir isotherm model performed better than other models, suggesting monolayer adsorption prevailed in the adsorption process. The theoretical adsorption capacities for Cu(II) were 12.7 mg/g and 9.01 mg/g for red alga and beer draff, respectively. The spectroscopy analyses and desorption studies showed that chemical bonding was the main mechanism in the adsorption process rather than ion exchange. The functional groups of amino, hydroxyl, carboxyl, phenolic hydroxyl, sulphonic group and C–O, –NH stretch might be involved in adsorption. After adsorption, both materials were successfully regenerated by nitric acid at a concentration of 10 mmol/L. Furthermore, the phenomenon that only 7% of adsorbed Cu(II) on red alga and 11% on beer draff were desorbed by sodium chloride solution suggested potential alternative of both materials for the treatment of road runoff containing considerable amounts of de-icing salt.展开更多
Using two new flexible and functional nitronyl nitroxide radicals as ligands, two copper (II) complexes {[Cu(hfac)<sub>2</sub>]<sub>3</sub>(NITmPhO3Py)<sub>2</sub>}<sub>n...Using two new flexible and functional nitronyl nitroxide radicals as ligands, two copper (II) complexes {[Cu(hfac)<sub>2</sub>]<sub>3</sub>(NITmPhO3Py)<sub>2</sub>}<sub>n</sub> (1) and [Cu(hfac)<sub>2</sub><sub> </sub>(NIToPhO3Py)]<sub>2</sub> (2) (NITmPhO3Py = 2-[(3-methoxy-pyridinyl)phen-3-yl]- 4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, NIToPhO3Py = 2-[(3-methoxy-pyridinyl)phen-2-ly]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, hfac = hexafluoroacetylacetone), have been characterized structurally and magnetically. The X-ray crystal analyses showed that complex 1 displayed a chain polymer structure which formed with {[Cu(hfac)<sub>2</sub>]<sub>3</sub>(NITmPhO3Py)<sub>2</sub>}<sub>n</sub> due to the cross-linking of two cyclic binuclear fragments {[Cu(hfac)<sub>2</sub>]<sub>2</sub>(NITmPhO3- Py)<sub>2</sub>} via the bridging unit [Cu(hfac)<sub>2</sub>];complex 2 presented a binuclear cyclic structure [Cu(hfac)<sub>2</sub>]<sub>2</sub>(NIToPhO3Py)<sub>2</sub>. The magnetic behaviors of the two complexes 1 and 2 have been investigated. Magnetic studies showed that antiferromagnetic interactions dominated in complex 1, while there existed ferromagnetic interactions between Cu(II) and coordinated NO group in complex 2.展开更多
Amino-functionalized magnetic nanoparticle (NH2-MNP) were prepared by a sol-gel approach. The adsorption behavior of Cu(II) ions on NH2-MNP was discussed systematically by batch experiments. The effects of initial...Amino-functionalized magnetic nanoparticle (NH2-MNP) were prepared by a sol-gel approach. The adsorption behavior of Cu(II) ions on NH2-MNP was discussed systematically by batch experiments. The effects of initial Cu(II) ions concentration, time, pH and temperature were investigated. In kinetic studies, the pseudo-second-order model was successfully employed, and the pseudo-first-order model substantiated that Cu(II) adsorption on NH2-MNP was a diffusion-based process. Langmuir model and Dubinin-Radushkevich model (R2〉0.99) were more corresponded with the adsorption isotherm data of Cu(II) ions than Freundlich model. The adsorption capacity was increased with the increment of temperature and pH. NH2-MNP remains excellent Cu(II) recoveries after reusing five adsorption and desorption cycles, making NH2-MNP a promising candidate for repetitively removing heavy metal ions from environmental water samples. According to the results obtained from adsorption activation energy and thermodynamic studies, it can be inferred that the main adsorption mechanism between absorbent and Cu(II) ions is ion exchange-surface complexation.展开更多
A facile one-step co-precipitation method was demonstrated to fabricate amorphous sulfurcontaining calcium phosphate (SCP) nanoparticles, in which the sulfur group was in-situ introduced into calcium phosphate. The ...A facile one-step co-precipitation method was demonstrated to fabricate amorphous sulfurcontaining calcium phosphate (SCP) nanoparticles, in which the sulfur group was in-situ introduced into calcium phosphate. The resulting SCP exhibited a noticeable enhanced performance for Pb(II) removal in comparison with hydroxyapatite (HAP), being capable of easily reducing 20 ppm of Pb(II) to below the acceptable standard for drinking water within less than 10 min. Remarkably, the saturated removal capacities of Pb(II) on SCP were as high as 1720.57 mg/g calculated by the Langmuir isotherm model, exceeding largely that of the previously reported absorbents. Significantly, SCP displayed highly selective removal ability toward Pb(II) ions in the presence of the competing metal ions (Ni(II), Co(II), Zn(II), and Cd(II)). Further investigations indicated that such ultra-high removal efficiency and preferable affinity of Pb(II) ions on SCP may be reasonably ascribed to the formation of rodlike hydroxypyromorphite crystals on the surface of SCP via dissolution-precipitation and ion exchange reactions, accompanied by the presence of lead sulfide precipitates. High removal efficiency, fast removal kinetics and excellent selectivity toward Pb(II) made the obtained SCP material an ideal candidate for Pb(II) ions decontamination in practical application.展开更多
In this work,the effect of ammonium sulfate on the adsorption characteristics of low-concentration Pb(Ⅱ)ions on the sulfidized hemimorphite surface was comprehensively investigated.The results showed that ammonium su...In this work,the effect of ammonium sulfate on the adsorption characteristics of low-concentration Pb(Ⅱ)ions on the sulfidized hemimorphite surface was comprehensively investigated.The results showed that ammonium sulfate could increase the maximum recovery of hemimorphite from 69.42%to 88.24%under a low concentration of Pb(Ⅱ)ions.On the hemimorphite surface pretreated with ammonium sulfate,the adsorption of Pb(Ⅱ)ions was enhanced and the main species of Pb adsorbed was changed from Pb―O/OH to PbS.This was due to the larger amount of ZnS providing more effective adsorption sites for Pb components to generate Pb S.Meanwhile,the intensity of ZnS decreased with the formation of PbS,demonstrating that ZnS was covered by PbS which formed later on the mineral surface.It was beneficial for the adsorption of butyl xanthate on the hemimorphite surface to form more hydrophobic substances.As a result,ammonium sulfate played a crucial role in realizing the efficient recovery of hemimorphite.展开更多
The adsorption behaviour of Cu2+ onto maghnite was conducted under batch conditions. The effect of time, pH of the dispersion, temperature and initial metal concentration on the adsorption of Cu2+ onto maghnite was in...The adsorption behaviour of Cu2+ onto maghnite was conducted under batch conditions. The effect of time, pH of the dispersion, temperature and initial metal concentration on the adsorption of Cu2+ onto maghnite was investigated. In this study, 94% of Cu(II), was adsorbed on the maghnite clay when the equilibrium was reached at 120 min. The adsorption of Cu2+ was a fast process that followed the pseudo-second-order kinetics. This process could be described by the Langmuir model and gave a maximum Cu2+ adsorption capacity of 21.78 mg/g at 293 K. The thermodynamic parameters such as variation of enthalpy ΔH, variation of entropy ΔS and variation of Gibbs free energy ΔG were calculated from the slope and intercept of lnKd vs. 1/T plots. The adsorption was endothermic reaction. The adsorption process for this natural maghnite is more spontaneous because the values of ΔG are less negative. The results suggested that natural maghnite was suitable as sorbent material for the recovery and adsorption of metal ion from aqueous solutions.展开更多
Highly oxidation. SEM analysis ordered anatase titania nanotube method was used to characterize arrays (TINT) were fabricated by anodic the morphology of the prepared samples. TiNT samples doped with Cu ions were pr...Highly oxidation. SEM analysis ordered anatase titania nanotube method was used to characterize arrays (TINT) were fabricated by anodic the morphology of the prepared samples. TiNT samples doped with Cu ions were prepared by home-made Metal Vapor Vacuum Arc ions sources (MEVVA, BNU, China) implanter. Photo-electric response and methyl orange decomposition ability of implanted samples under UV and visible light were tested, and the results indicated that the performance of Cu/TiNT enhanced significantly under visible light; it was noteworthy that the photocurrent density of A-Cu/TiNT was 0.102 mA/cm^2, which was 115 times that of pure TINT, and degradation ability of TiNT also strongly enhanced under visible light. In a word, the absorption spectrum of implanted anatase titania shifted to a longer wavelength region. Theoretic study on Cu-doped anatase based on density functional theory was carried out in this paper to validate the experiment results. The calculation results are depicted as follows: Intermittent energy band appeared around the Fermi energy after doping with Cu metal, the width of which was 0.35 eV and the location of valence and conduction bands shifted to the lower energy level by 0.22 eV; more excitation and jump routes were opened for the electrons. The narrowed band gaps allowed the photons with lower energy (at longer wavelength, such as visible light) to be absorbed, which accorded well with the experimental results.展开更多
The glutathione S-transferases gene family plays an important regulatory role in growth and development,and responses to environmental change.In this study,six complete GST genes(Mp GST1,Mp GST2,Mp GST3,MpGST4,Mp GST5...The glutathione S-transferases gene family plays an important regulatory role in growth and development,and responses to environmental change.In this study,six complete GST genes(Mp GST1,Mp GST2,Mp GST3,MpGST4,Mp GST5,and Mp GST6)were cloned from the gametophytes of brown alga Macrocystis pyrifera.Subsequent bioinformatics analysis showed that these six genes encoded proteins with 202,216,288,201,205,and 201 aa,respectively.Moreover,Mp GST3 differs from the other GST genes.Phylogenetic analysis suggested that MpGST3 belongs to the Ure2p type GST.Domain analysis suggested that the other GSTs from M.pyrifera belong to the soluble GST family and form an independent branch with the GSTs found in the other macroalgae,suggesting that a new GST type was formed during macroalgal evolution.GST genes were upregulated in M.pyrifera when 2.5 mg L^(-1)Cu ions were added to the medium.Six GST genes were integrated into the genome of Synechococcus elongatus PCC 7942,and their functions were verified by measuring light absorbance,photosynthetic pigment content,and photosynthetic parameters of the transformed strains under 0.3 mg L^(-1)Cu ion stress.The results showed much higher levels of various parameters in the transformed strains than in the wild strain.The transformed strains(with the MpGST genes)showed significantly enhanced resistance to Cu ion stress,while the wild strain almost died.The results of this study lay a theoretical foundation for further research on the Cu ion stress resistance function of GSTs in M.pyrifera.展开更多
In this study, the adsorption behavior of copper(II) ions from aqueous solutions onto sesame husk (SH) was investigated. The effect of different parameters such as pH, contact time, adsorbent dosage, adsorbate concent...In this study, the adsorption behavior of copper(II) ions from aqueous solutions onto sesame husk (SH) was investigated. The effect of different parameters such as pH, contact time, adsorbent dosage, adsorbate concentration, temperature and agitation speed was studied. Thermodynamic parameters, equilibrium isotherms and kinetic data have been evaluated. The functional groups and surface morphology of SH adsorbent were characterized by FTIR and SEM. Adsorption equilibrium isotherms were expressed by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) adsorption models and it was found that Langmuir adsorption model fits the experimental data better than Freundlich and D-R models. The adsorption can be best described by the pseudo second-order kinetic model.展开更多
To determine the environmental free metal ion activity was a recent hot issue. A method to measure low-level free cupric ion activity in soil solution extracted with 0.01 mol/L KNO3 was developed by using cupric ion-s...To determine the environmental free metal ion activity was a recent hot issue. A method to measure low-level free cupric ion activity in soil solution extracted with 0.01 mol/L KNO3 was developed by using cupric ion-selective electrode (ISE) and calibrating with Cu-buffer solution. Three copper buffers including iminodiacetic acid (IDA), ethylenediamine (EN), and glycine (Gly) were compared for calibrating the Cu-ISE curves in the range of free cupric ions (pCu^2+) 7-13. The Cu-EN buffer showed the best electrode response and thus was applied as the calibration buffer. The pCu^2+ of 39 contaminated agricultural soils around a copper mine was measured, ranging from 5.03 to 9.20. Most Cu in the soil solutions was found to be complexed with dissolved soil organic matters, averaging 98.1%. The proportion of free Cu^2+ ions in the soil solutions decreased with the increasing of solution pH. Soluble Cu and free Cu^2+ ions concentrations were analyzed by multiple linear regressions to evaluate the effects of soil properties on metal levels and speciation. The results showed that soil solution pH was the most significant factor influencing pCu^2+ (with R^2 value of 0.76), while not important for the soluble Cu concentration.展开更多
文摘In this study we used the deep eutectic solvents (ionic liquids) to investigate the reaction between copper (II) with ethylene diamine (en). Two of the existing methods for analyzing spectrophotometric measurements have been applied for establishing, the stoichiometry and whenever possible, the stability constants of the chelates formed. The method of continuous variations was necessary to determine first whether, the metal ion and the ligand ethylene diamine form one or more than one chelate, when more than one chelate formed, the results obtained depend on the wavelength and for meaningful conclusions the wavelengths were carefully selected. The empirical formulae of the chelates were further substantiated by the molar ratio method. The effect of time and temperature on the formation and stability of these chelates in solution is also studied. The stability constants, K1 and K2 for the copper (II) chelates were calculated, though reliable, and are comparable to literature values.
基金Funded by the Key R&D Projects in Hubei Province of China(No:2020BAB061)。
文摘Cu^(+)-doped alkali borosilicate glasses with different Na_(2)O contents were prepared by the melting method,and the effects of different R values(R=Na_(2)O/B_(2)O_(3))on the structure,ion presence state and luminescence properties of Cu^(+)-doped alkali borosilicate glasses were investigated.The analysis by FT-IR and Raman spectroscopy shows that,with the increase of R value of the glass,the[BO_(3)]in the structure of Cu^(+)-doped alkali borosilicate glass transforms into[BO_(4)]and the number of non-bridging oxygen in the glass network appears to be slightly increased.The absorption spectra and EPR analysis reveal that the Cu^(+)content in the glass gradually decreases and the Cu^(2+)content gradually increases as the R value of the glass increases.XPS and PL tests further indicate that the transformation of the octahedral coordination structure of Cu^(+)to the octahedral coordination structure of Cu^(2+)and the cubic coordination structure of Cu^(+)occurs in the glass as the R value of the glass increases.This transformation can effectively reduce the concentration quenching phenomenon of Cu^(+)and improve the fluorescence luminescence intensity of the glass samples.Meanwhile,the samples were found to have luminescence tunability as well as good thermal stability.
基金supported by National Natural Science Foundation of China(Nos.12064040,11874051,11904293,11864036)the Science and Technology Project of Gansu Province(Nos.21JR7RA122,20JR5RA530)the Funds for Innovative Fundamental Research Group Project of Gansu Province(No.20JR5RA541)。
文摘This paper reports the results of spectral measurements and a theoretical analysis of the temporal and spatial evolution of laser-produced Cu plasma in vacuum in the range of 8–14 nm.The time dependence of the extreme ultraviolet band spectrum at different positions near the target surface was obtained and found to be dominated by three broad-band features.The 3p and 3d excitations of Cu5+–Cu9+ions were calculated using the Hartree–Fock theory with configuration interactions.The characteristics of the spectral line distribution for the 3p–nd and 3d–nf transition arrays were analyzed.Based on the steady-state collisional radiation model and the normalized Boltzmann distribution,the complex spectral structure in the band of 13–14 nm is accurately explained through consistency comparisons and benchmarking between the experimental and theoretical simulation spectra,demonstrating that the structure mainly stems from the overlapping contribution of the 3d–4f and 3p–3d transition arrays for the Cu5+–Cu9+ions.These results may help in studying the radiation characteristics of isoelectronic series highly-charged ions involving the 3d excitation process.
文摘Adsorption of Cu(II) and Co(II) from aqueous solutions on synthetic nano Fe3O4 has been studied. The effect of experimental parameters such as initial concentration of the metal ions, adsorbent dosage, contact time and pH has been investigated. Optimum removal efficiency of Cu(II) ion was found to be 97.8% with the dose rate of 1.07 g/L in 60 minutes at pH = 5.5 and for Co(II) ion, it was found to be 99.2% with the dose rate of2.57 g/L in 10 minutes at pH = 5.4. The removal of Co(II) ions require only 10 minutes with the efficient removal of 99.2%, whereas Cu(II) ions require 60 minutes with the maximum removal of 97.8%. In order to understand the effective removal of Cu(II) and Co(II) ions on Fe3O4, room temperature magnetic measurement was carried out using Vibrational Spectrum Magnetometer (VSM), before and after adsorption with a maximum applied magnetic field of 20,000 G.
文摘In this study, the ability of red alga (Palmaria palmata) and beer draff (brewery waste) for Cu(II) removal was investigated. The influence of factors, such as pH, initial copper concentrations, and contact time, were also studied. Results showed the adsorption process was strongly dependent on the pH value and initial concentration. The optimum pH value was in the range of 5-6. The Langmuir isotherm model performed better than other models, suggesting monolayer adsorption prevailed in the adsorption process. The theoretical adsorption capacities for Cu(II) were 12.7 mg/g and 9.01 mg/g for red alga and beer draff, respectively. The spectroscopy analyses and desorption studies showed that chemical bonding was the main mechanism in the adsorption process rather than ion exchange. The functional groups of amino, hydroxyl, carboxyl, phenolic hydroxyl, sulphonic group and C–O, –NH stretch might be involved in adsorption. After adsorption, both materials were successfully regenerated by nitric acid at a concentration of 10 mmol/L. Furthermore, the phenomenon that only 7% of adsorbed Cu(II) on red alga and 11% on beer draff were desorbed by sodium chloride solution suggested potential alternative of both materials for the treatment of road runoff containing considerable amounts of de-icing salt.
文摘Using two new flexible and functional nitronyl nitroxide radicals as ligands, two copper (II) complexes {[Cu(hfac)<sub>2</sub>]<sub>3</sub>(NITmPhO3Py)<sub>2</sub>}<sub>n</sub> (1) and [Cu(hfac)<sub>2</sub><sub> </sub>(NIToPhO3Py)]<sub>2</sub> (2) (NITmPhO3Py = 2-[(3-methoxy-pyridinyl)phen-3-yl]- 4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, NIToPhO3Py = 2-[(3-methoxy-pyridinyl)phen-2-ly]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, hfac = hexafluoroacetylacetone), have been characterized structurally and magnetically. The X-ray crystal analyses showed that complex 1 displayed a chain polymer structure which formed with {[Cu(hfac)<sub>2</sub>]<sub>3</sub>(NITmPhO3Py)<sub>2</sub>}<sub>n</sub> due to the cross-linking of two cyclic binuclear fragments {[Cu(hfac)<sub>2</sub>]<sub>2</sub>(NITmPhO3- Py)<sub>2</sub>} via the bridging unit [Cu(hfac)<sub>2</sub>];complex 2 presented a binuclear cyclic structure [Cu(hfac)<sub>2</sub>]<sub>2</sub>(NIToPhO3Py)<sub>2</sub>. The magnetic behaviors of the two complexes 1 and 2 have been investigated. Magnetic studies showed that antiferromagnetic interactions dominated in complex 1, while there existed ferromagnetic interactions between Cu(II) and coordinated NO group in complex 2.
基金Project(CXZZ11-0812)supported by Graduate Students Innovative Projects of Jiangsu Province,ChinaProject(J20122288)supported by Guizhou Provincial Natural Science Foundation of China+1 种基金Project(Y4110235)supported by Zhejiang Provincial Natural Science Foundation of ChinaProject(JKY2011008)supported by Fundamental Research Funds for the Central Universities,China
文摘Amino-functionalized magnetic nanoparticle (NH2-MNP) were prepared by a sol-gel approach. The adsorption behavior of Cu(II) ions on NH2-MNP was discussed systematically by batch experiments. The effects of initial Cu(II) ions concentration, time, pH and temperature were investigated. In kinetic studies, the pseudo-second-order model was successfully employed, and the pseudo-first-order model substantiated that Cu(II) adsorption on NH2-MNP was a diffusion-based process. Langmuir model and Dubinin-Radushkevich model (R2〉0.99) were more corresponded with the adsorption isotherm data of Cu(II) ions than Freundlich model. The adsorption capacity was increased with the increment of temperature and pH. NH2-MNP remains excellent Cu(II) recoveries after reusing five adsorption and desorption cycles, making NH2-MNP a promising candidate for repetitively removing heavy metal ions from environmental water samples. According to the results obtained from adsorption activation energy and thermodynamic studies, it can be inferred that the main adsorption mechanism between absorbent and Cu(II) ions is ion exchange-surface complexation.
文摘A facile one-step co-precipitation method was demonstrated to fabricate amorphous sulfurcontaining calcium phosphate (SCP) nanoparticles, in which the sulfur group was in-situ introduced into calcium phosphate. The resulting SCP exhibited a noticeable enhanced performance for Pb(II) removal in comparison with hydroxyapatite (HAP), being capable of easily reducing 20 ppm of Pb(II) to below the acceptable standard for drinking water within less than 10 min. Remarkably, the saturated removal capacities of Pb(II) on SCP were as high as 1720.57 mg/g calculated by the Langmuir isotherm model, exceeding largely that of the previously reported absorbents. Significantly, SCP displayed highly selective removal ability toward Pb(II) ions in the presence of the competing metal ions (Ni(II), Co(II), Zn(II), and Cd(II)). Further investigations indicated that such ultra-high removal efficiency and preferable affinity of Pb(II) ions on SCP may be reasonably ascribed to the formation of rodlike hydroxypyromorphite crystals on the surface of SCP via dissolution-precipitation and ion exchange reactions, accompanied by the presence of lead sulfide precipitates. High removal efficiency, fast removal kinetics and excellent selectivity toward Pb(II) made the obtained SCP material an ideal candidate for Pb(II) ions decontamination in practical application.
基金the Fundamental Research Funds for the Central Universities(Nos.2022JCCXHH09 and 2022YJSHH01)the Yueqi Outstanding Scholar award of CUMTB+3 种基金the National Key R&D Program of China(No.SQ2022YFC2900065)the Ordos Science&Technology Plan(No.202204)the National Natural Science Foundation of China(No.52274283)the Open Research Fund of State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization(No.CNMRCUKF2107)。
文摘In this work,the effect of ammonium sulfate on the adsorption characteristics of low-concentration Pb(Ⅱ)ions on the sulfidized hemimorphite surface was comprehensively investigated.The results showed that ammonium sulfate could increase the maximum recovery of hemimorphite from 69.42%to 88.24%under a low concentration of Pb(Ⅱ)ions.On the hemimorphite surface pretreated with ammonium sulfate,the adsorption of Pb(Ⅱ)ions was enhanced and the main species of Pb adsorbed was changed from Pb―O/OH to PbS.This was due to the larger amount of ZnS providing more effective adsorption sites for Pb components to generate Pb S.Meanwhile,the intensity of ZnS decreased with the formation of PbS,demonstrating that ZnS was covered by PbS which formed later on the mineral surface.It was beneficial for the adsorption of butyl xanthate on the hemimorphite surface to form more hydrophobic substances.As a result,ammonium sulfate played a crucial role in realizing the efficient recovery of hemimorphite.
文摘The adsorption behaviour of Cu2+ onto maghnite was conducted under batch conditions. The effect of time, pH of the dispersion, temperature and initial metal concentration on the adsorption of Cu2+ onto maghnite was investigated. In this study, 94% of Cu(II), was adsorbed on the maghnite clay when the equilibrium was reached at 120 min. The adsorption of Cu2+ was a fast process that followed the pseudo-second-order kinetics. This process could be described by the Langmuir model and gave a maximum Cu2+ adsorption capacity of 21.78 mg/g at 293 K. The thermodynamic parameters such as variation of enthalpy ΔH, variation of entropy ΔS and variation of Gibbs free energy ΔG were calculated from the slope and intercept of lnKd vs. 1/T plots. The adsorption was endothermic reaction. The adsorption process for this natural maghnite is more spontaneous because the values of ΔG are less negative. The results suggested that natural maghnite was suitable as sorbent material for the recovery and adsorption of metal ion from aqueous solutions.
基金Supported by the National Natural Science Foundation of China (No. 10975020)Key Laboratory of BeamTechnology and Material Modification of Ministry of Education, Beijing Normal University
文摘Highly oxidation. SEM analysis ordered anatase titania nanotube method was used to characterize arrays (TINT) were fabricated by anodic the morphology of the prepared samples. TiNT samples doped with Cu ions were prepared by home-made Metal Vapor Vacuum Arc ions sources (MEVVA, BNU, China) implanter. Photo-electric response and methyl orange decomposition ability of implanted samples under UV and visible light were tested, and the results indicated that the performance of Cu/TiNT enhanced significantly under visible light; it was noteworthy that the photocurrent density of A-Cu/TiNT was 0.102 mA/cm^2, which was 115 times that of pure TINT, and degradation ability of TiNT also strongly enhanced under visible light. In a word, the absorption spectrum of implanted anatase titania shifted to a longer wavelength region. Theoretic study on Cu-doped anatase based on density functional theory was carried out in this paper to validate the experiment results. The calculation results are depicted as follows: Intermittent energy band appeared around the Fermi energy after doping with Cu metal, the width of which was 0.35 eV and the location of valence and conduction bands shifted to the lower energy level by 0.22 eV; more excitation and jump routes were opened for the electrons. The narrowed band gaps allowed the photons with lower energy (at longer wavelength, such as visible light) to be absorbed, which accorded well with the experimental results.
基金supported by the National Key R&D Program of China(No.2018YFD0900305)the National Natural Science Foundation of China(No.31770393)+5 种基金the Major Scientific and Technological Innovation Project of Shandong Provincial Key Research and Development Program(No.2019JZZY020706)the Central Public-Interest Scientific Institute Basal Research Fund,CAFS(Nos.2020TD 19 and 2020TD27)the China Agriculture Research System(CARS-50)the Taishan Scholars Funding of Shandong Provincethe Taishan Scholars Funding and Talent Projects of Distinguished Scientific Scholars in AgricultureYoung Taishan Scholars Program to DONG Xu。
文摘The glutathione S-transferases gene family plays an important regulatory role in growth and development,and responses to environmental change.In this study,six complete GST genes(Mp GST1,Mp GST2,Mp GST3,MpGST4,Mp GST5,and Mp GST6)were cloned from the gametophytes of brown alga Macrocystis pyrifera.Subsequent bioinformatics analysis showed that these six genes encoded proteins with 202,216,288,201,205,and 201 aa,respectively.Moreover,Mp GST3 differs from the other GST genes.Phylogenetic analysis suggested that MpGST3 belongs to the Ure2p type GST.Domain analysis suggested that the other GSTs from M.pyrifera belong to the soluble GST family and form an independent branch with the GSTs found in the other macroalgae,suggesting that a new GST type was formed during macroalgal evolution.GST genes were upregulated in M.pyrifera when 2.5 mg L^(-1)Cu ions were added to the medium.Six GST genes were integrated into the genome of Synechococcus elongatus PCC 7942,and their functions were verified by measuring light absorbance,photosynthetic pigment content,and photosynthetic parameters of the transformed strains under 0.3 mg L^(-1)Cu ion stress.The results showed much higher levels of various parameters in the transformed strains than in the wild strain.The transformed strains(with the MpGST genes)showed significantly enhanced resistance to Cu ion stress,while the wild strain almost died.The results of this study lay a theoretical foundation for further research on the Cu ion stress resistance function of GSTs in M.pyrifera.
基金Project(2004CB619205)supported by the National Basic Research Program of ChinaProject(50674102)supported by the National Natural Science Foundation of ChinaProject(2007AA060902)supported by High-tech Research and Development Program of China
文摘In this study, the adsorption behavior of copper(II) ions from aqueous solutions onto sesame husk (SH) was investigated. The effect of different parameters such as pH, contact time, adsorbent dosage, adsorbate concentration, temperature and agitation speed was studied. Thermodynamic parameters, equilibrium isotherms and kinetic data have been evaluated. The functional groups and surface morphology of SH adsorbent were characterized by FTIR and SEM. Adsorption equilibrium isotherms were expressed by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) adsorption models and it was found that Langmuir adsorption model fits the experimental data better than Freundlich and D-R models. The adsorption can be best described by the pseudo second-order kinetic model.
基金The National Key Basic Research Program (973) of China (No. 2002CB410808) and CAS Research Program on Soil Biosystems andAgro-Product Safety (No. CXTD-Z2005-4-1)
文摘To determine the environmental free metal ion activity was a recent hot issue. A method to measure low-level free cupric ion activity in soil solution extracted with 0.01 mol/L KNO3 was developed by using cupric ion-selective electrode (ISE) and calibrating with Cu-buffer solution. Three copper buffers including iminodiacetic acid (IDA), ethylenediamine (EN), and glycine (Gly) were compared for calibrating the Cu-ISE curves in the range of free cupric ions (pCu^2+) 7-13. The Cu-EN buffer showed the best electrode response and thus was applied as the calibration buffer. The pCu^2+ of 39 contaminated agricultural soils around a copper mine was measured, ranging from 5.03 to 9.20. Most Cu in the soil solutions was found to be complexed with dissolved soil organic matters, averaging 98.1%. The proportion of free Cu^2+ ions in the soil solutions decreased with the increasing of solution pH. Soluble Cu and free Cu^2+ ions concentrations were analyzed by multiple linear regressions to evaluate the effects of soil properties on metal levels and speciation. The results showed that soil solution pH was the most significant factor influencing pCu^2+ (with R^2 value of 0.76), while not important for the soluble Cu concentration.