为了明确La(Ⅲ)改性沸石脱除模拟硫酸锌溶液中氟离子的机理,利用XRD、SEM和EDX对吸附剂进行表征,研究吸附剂用量和吸附时间对吸附过程的影响,采用吸附等温线与吸附动力学对吸附过程进行探究。结果表明,Langmuir吸附等温线模型更适合吸...为了明确La(Ⅲ)改性沸石脱除模拟硫酸锌溶液中氟离子的机理,利用XRD、SEM和EDX对吸附剂进行表征,研究吸附剂用量和吸附时间对吸附过程的影响,采用吸附等温线与吸附动力学对吸附过程进行探究。结果表明,Langmuir吸附等温线模型更适合吸附过程;在303和313 K条件下,吸附剂的最大理论吸附容量分别为20.83和23.04 mg/g;Temkin和D-R吸附等温线模型证明氟离子脱除过程为物理吸附,且吸附过程遵从准二级动力学模型;同时,热力学计算结果(?G~Θ<0 k J/mol,?H~Θ=8.28 k J/mol,?S~Θ=0.030 k J/(mol?K))说明La(Ⅲ)改性沸石脱除模拟硫酸锌溶液中氟离子是自发、吸热的物理过程;将La(Ⅲ)改性沸石应用在工业硫酸锌溶液中,用量为15 g/L时,氟离子浓度从98.05 mg/L降低至44.09 mg/L。展开更多
Solvent extraction experiments of La(III) with di-(2-ethylhexyl)phosphoric acid (P204) from chloride solution in the presence of a complexing agent (lactic acid) have been performed. The effective separation factors c...Solvent extraction experiments of La(III) with di-(2-ethylhexyl)phosphoric acid (P204) from chloride solution in the presence of a complexing agent (lactic acid) have been performed. The effective separation factors can be achieved when the complexing agent is added to the aqueous phase of the extraction system. The complexing agent lactic acid can be effectively recycled using tributyl phosphate (TBP) as extractant, by the use of a countercurrent extraction process, and the chemical oxygen demand (COD) value in the raffinate is 57.7 mg/L, which meets the emission standards of pollutants from rare earths industry. Thus, the simple and environment-friendly complexing method has been proved to be an effective strategy for separating light rare earths, and provides a positive influence on the purification of La(III).展开更多
A new ligand N,N′-bis(2-methelene-1,10-phenanthroline)-3,6-dioxa-1,8-octaneethylenediamine(L) and the corresponding complexes LaL, LaL(Phe), and LaL( Try) were synthesized. The interaction of the complexes with calf ...A new ligand N,N′-bis(2-methelene-1,10-phenanthroline)-3,6-dioxa-1,8-octaneethylenediamine(L) and the corresponding complexes LaL, LaL(Phe), and LaL( Try) were synthesized. The interaction of the complexes with calf thymus DNA was studied by means of electronic absorbance spectra, flurescence spectra, circula r dichroic spectra and viscosity experiments. All the results indicate that the complexes may interact mainly with calf thymus DNA by intercalation and coordina tion binding.展开更多
Developing low-cost and effective materials for excess fluoride removal is important for providing safe water. A novel adsorbent, La(Ⅲ)-loaded bentonite/chitosan beads(La-BCB) was prepared for defluoridation from aqu...Developing low-cost and effective materials for excess fluoride removal is important for providing safe water. A novel adsorbent, La(Ⅲ)-loaded bentonite/chitosan beads(La-BCB) was prepared for defluoridation from aqueous solution. The effects of various parameters such as dosage of La(Ⅲ), pH, temperature, contact time, initial fluoride concentration and presence of co-existing anions were investigated to examine the defluoridation behavior. The maximum defluoridation capacity of La-BCB was 2.87 mg/g at pH 5, 30 °C. Scanning electron microscopy(SEM), energy dispersive spectroscopy(EDX) and Fourier transform infrared spectroscopy(FTIR) were employed to analyze the characteristics of La-BCB. The equilibrium fluoride adsorption data fitted well with both Langmuir and Freundlich isotherm models. The RL value revealed that the defluoridation process using La-BCB was favorable. The adsorption kinetics followed pseudo-second order kinetic as well as particle and intraparticle diffusion models. The presence of carbonate and bicarbonate reduced defluoridation capacity of La-BCB while sulphate, nitrate and chloride showed slight effect. The exhausted La-BCB was regenerated using sodium hydroxide with only 17% loss. The reasonable defluoridation mechanism could be interpreted as adsorption and ion exchange.展开更多
In this study a series of trivalent lanthanum complexes with 4-(R)-cinnamate(4-Rcinn,R=H(1),MeO(2),Cl(3))and4-methoxyphenylacetate ligands(4)were prepared and their antifungal activity against Candida albicans,Aspergi...In this study a series of trivalent lanthanum complexes with 4-(R)-cinnamate(4-Rcinn,R=H(1),MeO(2),Cl(3))and4-methoxyphenylacetate ligands(4)were prepared and their antifungal activity against Candida albicans,Aspergillus niger and Trichophyton mentagrophytes were examined.Compounds 1–4 were synthesized by a metathesis reaction and fully characterized by elemental analysis,IR,1H and13C NMR spectroscopy,fluorescence spectra,thermogravimetry(TG),derivative thermogravimetry(DTG),differential scanning calorimetry(DSC)and X-ray diffraction powder patterns.In emission studies,it was observed that luminescence intensity was enhanced in the presence of lanthanide ion.The results of X-ray diffraction patterns indicated that all complexes studied exhibited crystalline structure.Thermal behavior by TG,DTG,and DSC studies permitted to estimating the hydration degree of the compounds and showed the formation of decomposition products like lanthanum oxide.Determined by antifungal studies,lanthanum complexes 1–4 demonstrated antifungal activity toward all pathogenic fungal strains tested.Compounds 2 and 4showed significant growth inhibition for A.niger and C.albicans,respectively.展开更多
This paper described the fluoride removal from water using a new adsorbent namely mixed rare earths modified chitosan (CR). Mixed rare earths mainly contained La followed by Ce which was analyzed by inductively couple...This paper described the fluoride removal from water using a new adsorbent namely mixed rare earths modified chitosan (CR). Mixed rare earths mainly contained La followed by Ce which was analyzed by inductively coupled plasma mass spectrometry (ICP-MS). La(III)-modified chitosan (CL) was also prepared as control. For the batch technique, the effects of various parameters such as contact time, pH, adsorbent dose, initial fluoride concentration and co-ions on fluoride adsorption were studied. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were used to characterize adsorbents. It was observed that the fluoride adsorption capacity of CR (3.72mgF-/g) was higher than CL (3.16mgF-/g) at 2h. The presence of co-ions such as bicarbonate and carbonate greatly affected the fluoride adsorption from water. Characterization experiments indicated the successful chelation between mixed rare earths and chitosan. The possible fluoride adsorption mechanism of CR was explained by a chemical reaction.展开更多
基金Projects(51474238,51674301)supported by the National Natural Science Foundation of China
文摘为了明确La(Ⅲ)改性沸石脱除模拟硫酸锌溶液中氟离子的机理,利用XRD、SEM和EDX对吸附剂进行表征,研究吸附剂用量和吸附时间对吸附过程的影响,采用吸附等温线与吸附动力学对吸附过程进行探究。结果表明,Langmuir吸附等温线模型更适合吸附过程;在303和313 K条件下,吸附剂的最大理论吸附容量分别为20.83和23.04 mg/g;Temkin和D-R吸附等温线模型证明氟离子脱除过程为物理吸附,且吸附过程遵从准二级动力学模型;同时,热力学计算结果(?G~Θ<0 k J/mol,?H~Θ=8.28 k J/mol,?S~Θ=0.030 k J/(mol?K))说明La(Ⅲ)改性沸石脱除模拟硫酸锌溶液中氟离子是自发、吸热的物理过程;将La(Ⅲ)改性沸石应用在工业硫酸锌溶液中,用量为15 g/L时,氟离子浓度从98.05 mg/L降低至44.09 mg/L。
文摘Solvent extraction experiments of La(III) with di-(2-ethylhexyl)phosphoric acid (P204) from chloride solution in the presence of a complexing agent (lactic acid) have been performed. The effective separation factors can be achieved when the complexing agent is added to the aqueous phase of the extraction system. The complexing agent lactic acid can be effectively recycled using tributyl phosphate (TBP) as extractant, by the use of a countercurrent extraction process, and the chemical oxygen demand (COD) value in the raffinate is 57.7 mg/L, which meets the emission standards of pollutants from rare earths industry. Thus, the simple and environment-friendly complexing method has been proved to be an effective strategy for separating light rare earths, and provides a positive influence on the purification of La(III).
文摘A new ligand N,N′-bis(2-methelene-1,10-phenanthroline)-3,6-dioxa-1,8-octaneethylenediamine(L) and the corresponding complexes LaL, LaL(Phe), and LaL( Try) were synthesized. The interaction of the complexes with calf thymus DNA was studied by means of electronic absorbance spectra, flurescence spectra, circula r dichroic spectra and viscosity experiments. All the results indicate that the complexes may interact mainly with calf thymus DNA by intercalation and coordina tion binding.
基金Supported by the Foundation of State Developing and ReformingCommittee(No.IFZ20051210)the National Natural Science Foundationof China(No.30570323,No.20471030)the Programsin Science and Technology of Nantong(No.DE2009006,No.S2009019)~~
基金Project supported by National Special Fund for Scientific Research on Public Causes(201005020)China Postdoctoral Science Foundation(2013M531652)National Natural Science Foundation of China(31302162)
文摘Developing low-cost and effective materials for excess fluoride removal is important for providing safe water. A novel adsorbent, La(Ⅲ)-loaded bentonite/chitosan beads(La-BCB) was prepared for defluoridation from aqueous solution. The effects of various parameters such as dosage of La(Ⅲ), pH, temperature, contact time, initial fluoride concentration and presence of co-existing anions were investigated to examine the defluoridation behavior. The maximum defluoridation capacity of La-BCB was 2.87 mg/g at pH 5, 30 °C. Scanning electron microscopy(SEM), energy dispersive spectroscopy(EDX) and Fourier transform infrared spectroscopy(FTIR) were employed to analyze the characteristics of La-BCB. The equilibrium fluoride adsorption data fitted well with both Langmuir and Freundlich isotherm models. The RL value revealed that the defluoridation process using La-BCB was favorable. The adsorption kinetics followed pseudo-second order kinetic as well as particle and intraparticle diffusion models. The presence of carbonate and bicarbonate reduced defluoridation capacity of La-BCB while sulphate, nitrate and chloride showed slight effect. The exhausted La-BCB was regenerated using sodium hydroxide with only 17% loss. The reasonable defluoridation mechanism could be interpreted as adsorption and ion exchange.
文摘In this study a series of trivalent lanthanum complexes with 4-(R)-cinnamate(4-Rcinn,R=H(1),MeO(2),Cl(3))and4-methoxyphenylacetate ligands(4)were prepared and their antifungal activity against Candida albicans,Aspergillus niger and Trichophyton mentagrophytes were examined.Compounds 1–4 were synthesized by a metathesis reaction and fully characterized by elemental analysis,IR,1H and13C NMR spectroscopy,fluorescence spectra,thermogravimetry(TG),derivative thermogravimetry(DTG),differential scanning calorimetry(DSC)and X-ray diffraction powder patterns.In emission studies,it was observed that luminescence intensity was enhanced in the presence of lanthanide ion.The results of X-ray diffraction patterns indicated that all complexes studied exhibited crystalline structure.Thermal behavior by TG,DTG,and DSC studies permitted to estimating the hydration degree of the compounds and showed the formation of decomposition products like lanthanum oxide.Determined by antifungal studies,lanthanum complexes 1–4 demonstrated antifungal activity toward all pathogenic fungal strains tested.Compounds 2 and 4showed significant growth inhibition for A.niger and C.albicans,respectively.
基金supported by National Natural Science Foundation of China (31101330)International Joint Research Program(2010DFA31330)Public Science and Technology Research Funds Projects of Ocean (201005020-6)
文摘This paper described the fluoride removal from water using a new adsorbent namely mixed rare earths modified chitosan (CR). Mixed rare earths mainly contained La followed by Ce which was analyzed by inductively coupled plasma mass spectrometry (ICP-MS). La(III)-modified chitosan (CL) was also prepared as control. For the batch technique, the effects of various parameters such as contact time, pH, adsorbent dose, initial fluoride concentration and co-ions on fluoride adsorption were studied. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were used to characterize adsorbents. It was observed that the fluoride adsorption capacity of CR (3.72mgF-/g) was higher than CL (3.16mgF-/g) at 2h. The presence of co-ions such as bicarbonate and carbonate greatly affected the fluoride adsorption from water. Characterization experiments indicated the successful chelation between mixed rare earths and chitosan. The possible fluoride adsorption mechanism of CR was explained by a chemical reaction.
