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1.
Various adsorbent materials have been reported in the literature for protein separation. We have developed a novel and new approach to obtain high protein‐adsorption capacity utilizing a 2‐methacrylamidoalanine‐containing membrane. An amino acid ligand 2‐methacrylamidoalanine (MAAL) was synthesized from methacrylochloride and alanine. Then, poly[(2‐hydroxyethyl methacrylate)‐co‐(2‐methacrylamidoalanine)] [p(HEMA‐co‐MAAL)] membranes were prepared by UV‐initiated photopolymerization of HEMA and MAAL. The synthesized MAAL monomer was characterized by NMR spectrometry. p(HEMA‐co‐MAAL) membranes were characterized by swelling studies, porosimeter, scanning electron microscopy, FT‐IR spectroscopy and elemental analysis. These membranes have large pores; the micropore dimensions are around 5–10 μm. p(HEMA‐co‐MAAL) affinity membranes with a swelling ratio of 198.9%, and containing 23.9 (mmol MAAL)·m–2 were used in the adsorption of lysozyme from aqueous media containing different amounts of lysozyme (0.1–3.0 mg·ml–1) and at different pH values (4.0–8.0). The effect of Cu(II) incorporation on lysozyme adsorption was also studied. The non‐specific adsorption of lysozyme on the pHEMA membranes was 0.9 μg‐cm–2. Incorporation of MAAL molecules into the polymeric structure significantly increased the lysozyme adsorption up to 2.96 mg·cm–2. The lysozyme‐adsorption capacity of the membranes incorporated with Cu(II) (9.98 mg·cm–2) was greater than that of the p(HEMA‐co‐MAAL) membranes. More than 85% of the adsorbed lysozyme was desorbed in 1 h in the desorption medium containing 1.0 M NaCl. The p(HEMA‐co‐MAAL) membranes are suitable for repeated use for more than 5 cycles without noticeable loss of capacity. These features make p(HEMA‐co‐MAAL) membrane a very good candidate for bioaffinity adsorption.  相似文献   

2.
Different metal-complexing ligands carrying synthetic adsorbents have been reported in the literature for heavy metal removal. We have developed a novel and new approach to obtain high metal adsorption capacity utilizing 2-methacrylamidohistidine (MAH) as a metal-complexing ligand. MAH was synthesized by using methacrylochloride and histidine. Spherical beads with an average size of 150–200 μm were obtained by the radical suspension polymerization of MAH and 2-hydroxyethylmethacrylate (HEMA) conducted in an aqueous dispersion medium. Owing to the reasonably rough character of the bead surface, p(HEMA-co-MAH) beads had a specific surface area of 17.6 m2 g−1. Synthesized MAH monomer was characterized by NMR. p(HEMA-co-MAH) beads were characterized by swelling studies, FTIR and elemental analysis. These p(HEMA-co-MAH) affinity beads with a swelling ratio of 65%, and containing 1.6 mmol MAH g−1 were used in the adsorption/desorption of copper(II) ions from metal solutions. Adsorption equilibria was achieved in ∼2 h. The maximum adsorption of Cu(II) ions onto pHEMA was ∼0.36 mg Cu(II) g−1. The MAH incorporation significantly increased the Cu(II) adsorption capacity by chelate formation of Cu(II) ions with MAH molecules (122.7 mg Cu(II) g−1), which was observed at pH 7.0. pH significantly affected the adsorption capacity of MAH incorporated beads. The observed adsorption order under non-competitive conditions was Cu(II)>Cr(III)>Hg(II)>Pb(II)>Cd(II) in molar basis. The chelating beads can be easily regenerated by 0.1 M HNO3 with higher effectiveness. These features make p(HEMA-co-MAH) beads very good candidate for Cu(II) removal at high adsorption capacity.  相似文献   

3.
Novel adsorbents which can concentrate Th(IV) in aqueous solution were prepared by immobilizingMyrica rubra tannin and larch tannin onto collagen fibre matrices. The adsorption capacities of the immobilized tannins to Th(IV) are related to temperature and pH value of the adsorption process. For example, when the initial concentration of Th(IV) was 116.0 mg·l-1 and the immobilized tannin was 100 mg, the adsorption capacities of immobilized Myrica rubra tannin and larch tannin were 55.98 mg Th(IV)·g-1 and 13.19 mg Th(IV)·g-1, respectively at 303 K, and 73.67 mg Th(IV)·g-1 and 18.19 mg Th(IV)·g-1 at 323 K. It was also found that the higher adsorption capacity was obtained at higher pH value. The adsorption equilibrium data of the immobilized tannins for Th(IV) can be well fitted by the Langmuir model and the mechanism of the adsorption was found to be a chemical adsorption. In general, the adsorption capacity of immobilized Myrica rubra tannin to Th(IV) is significantly higher than that of immobilized larch tannin, probably due to the fact that the B ring of Myrica rubra tannin has a pyrogallol structure which has higher reaction activity with metal ions. The breakthrough point of the adsorption column of immobilized Myrica rubra tannin was at 33 bed volumes for the experimental system. The mass transfer coefficient of adsorption column determined by Adams-Bohart equation was 1.61·10-4 l·mg-1.min-1. The adsorption column can be easily regenerated by 0.1 mol·l-1 HNO3 solution, showing outstanding ability of concentrating Th(IV). This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

4.
本文利用荧光猝灭法、红外光谱法及计算机模拟技术研究了一种聚酰亚胺聚合物(2,6-Bis(4-amino-2-trifluoromethyl phenoxy-4’- benzoyl)-pyridine,简称BAFP )与人免疫球蛋白(HIgG)的相互作用。同步荧光的结果定性地说明了BAFP影响水溶液中HIgG二级结构的情况。而判定BAFP影响HIgG二级结构的定量依据来自红外光谱,实验数据表明α螺旋结构的含量相比未加入药物时增加了约2.6~10.2%,,β折叠增大了约13.6~27.7%,,而β转角则减小了约23.8~30.3%。分子模拟的结果显示BAFP与HIgG的键合作用很强,并且有四个氢键在BAFP与HIgG分子的色氨酸Trp 170, 缬氨酸Val 105, 甲硫氨酸Met 139 及天冬酰胺Asn 52之间形成;同时也显示出维持药物与蛋白质的相互作用力主要是疏水作用,这与实验所得到的热力学参数判定作用力的结果相一致(依据范德霍夫公式计算得 与 的值分别为-6.70KJ.mol-1 和 71.93 J.mol-1.K-1)。  相似文献   

5.
本文以多孔碳纳米管/活性炭复合微球为载体, 以L-色氨酸为配基, 采用环氧氯丙烷偶联法, 制得修饰L-色氨酸的碳纳米管/活性炭复合微球(L-CNTs/AC)。采用扫描电镜、氮气吸附、傅立叶红外光谱、热分析、X射线光电子能谱等对复合微球进行表征;通过体外静态吸附法对其低密度脂蛋白(LDL)吸附能力进行初步研究。结果表明:环氧氯丙烷偶联法可接枝上L-色氨酸。复合微球中碳纳米管加入量越多, 对LDL的吸附能力越强;当碳纳米管加入量为45wt%时, 对LDL的吸附量达4.623 mg·g-1, 是未添加碳纳米管的2.3倍多。这是因为碳纳米管不仅可促进复合微球中20~100 nm孔的形成, 而且还可促进复合微球配基修饰量的增多, 从而大大增强了复合微球对LDL的吸附能力。此复合微球可望开发成一种新型的血液灌流LDL吸附剂。  相似文献   

6.
Highly ordered amino‐functionalized hexagonal mesoporous silica (HMS‐NH2) had been synthesized successfully by co‐condensation. The resultant materials were characterized by means of XRD, TEM, FT‐IR, N2 ad‐desorption and 29Si NMR to confirm the ordered mesoporous structure and the functionalization of the amino groups. The sample was employed as a Pb2+ adsorbent in aqueous solutions at room temperature. Both Lagergren's first order kinetic model and Lagergren's second order kinetic model were used to describe the adsorption data. It was found that the pseudo second order model fitted the sorption kinetic data better than the pseudo first order model. According to the information analyzed from AAS, HMS‐NH2 had a Pb2+ adsorption amount of over 90.7 mg·g?1, showing a promising application for the treatment of wastewater containing Pb2+ ions.  相似文献   

7.
Graphene-like layered hexagonal boron nitride (g-BN) was prepared and characterized. The performance of using g-BN as an adsorbent for removal of fluoroquinolone antibiotic gatifloxacin (GTF) from aqueous solution was evaluated. g-BN showed an excellent adsorption capability with notable GTF adsorption ratio of more than 90%. Data of equilibrium adsorption of GTF onto g-BN at different temperatures were represented by Langmuir, Freundlich and Tempkin isotherm models, and Langmuir exhibited the best fitting with the maximum adsorption capacity of 88.5 mg·g?1 at 288 K. GTF adsorption was insignificantly affected by solution pH. Competitive role of Na+ and Ca2+ in the solution inhibited the adsorption of GTF and decreased the adsorption capacity a bit. The adsorption process was spontaneous and exothermic. The adsorption was probably governed by π–π interaction between GTF and g-BN, and electrostatic interaction may also exist in the adsorption process.  相似文献   

8.
Organic arsenic compounds in the environment are a global threat to human health. This threat has created the urgency to develop highly efficient adsorbents with both high adsorption capacity and versatile removal of different arsenic compounds. A novel 1D zinc(II) coordination polymer, formulated as Zn2(datrz)2(bpy)Cl2 ( BUC-70 ) (datrz = guanazole, bpy = 4,4′-bipyridine), was successfully synthesized through slow evaporation at room temperature. BUC-70 exhibited an excellent adsorption capacity toward p-arsanilic acid (p-ASA) and roxarsone (ROX) in water, which could be ascribed to As–O–Zn bonding interactions and strong hydrogen-bonding interactions between the organic arsenics and BUC-70 . The maximum adsorption capacities toward p-ASA and ROX were 738 and 937 mg·g−1, respectively. BUC-70 was effective in the removal of p-ASA and ROX at low concentrations (<5 mg·l−1) from the simulated p-ASA and ROX wastewater. Furthermore, the as-synthesized BUC-70 exhibited good adsorption property toward p-ASA and ROX in wastewater simulated by lake water and tap water. After adsorptive treatment using BUC-70 , the concentrations of both p-ASA and ROX were lower than the required concentrations of the drinking water standard of the World Health Organization and the surface water standard of China. Continuous-flow, fixed-bed column experiments were performed using BUC-70 loaded on cotton as packing material to explore the potential large-scale application.  相似文献   

9.
A Cd(II)-imprinted thiocyanato-functionalized silica gel adsorbent with high adsorption capacity was prepared by surface imprinting technique combined with sol–gel process for the selective adsorption of Cd(II) ion in aqueous solution, and was characterized by Fourier-transform infrared spectroscopy, nitrogen gas sorption and thermogravimetric analysis. The influences of different conditions (such as the pH of solutions, the contact time and the initial concentrations of Cd(II) ions) on the adsorption capacity of Cd(II) were investigated. The optimum pH of adsorption was in the range of 4–8.5. The adsorption equilibrium could be reached in 20 min. The relatively selectivity coefficients of the imprinted silica were higher than those of the non-imprinted adsorbents. Ho’s pseudo-second-order model well described the kinetics of the adsorption reaction. The adsorption process of metals followed Redlich–Peterson isotherm model, and the experimental value of maximum adsorption capacity for Cd(II) was 72.8 mg·g?1. The positive value of ΔH o suggested endothermic nature of Cd(II) adsorption on the imprinted silica adsorbent. Increase in entropy of adsorption reaction was shown by the positive value of ΔS o and the negative value of ΔG o indicating that the adsorption was spontaneous in nature.  相似文献   

10.
Silicate mercapto Duolite composite ( SMDC ) and activated Duolite A 101 D ( AD ) were prepared, characterized, and tested for uranium removal from sulfate solution using batch experiment technique. The capability of newly adsorbents for sorption of uranium was estimated and optimized under different controlling variables, including the impact of uranium initial concentration, pH of the medium, equilibrium time, temperatures, dose and interfering ions. Testing of different adsorbents for adsorption isotherms revealed that the achieved experimental data were fitting well with the Langmuir isotherm model with 68.02 mg · g–1 and 208.33 mg · g–1 as theoretical capacity for AD and SMDC , respectively. Thermodynamic parameters have been resulted in negative values for ΔH and ΔS indicating an exothermic and decreased randomness behavior for uranium(VI) adsorption, while negative values of ΔG indicate spontaneous uranium adsorption. The kinetics studies showed that the adsorption process was controlled expressed by pseudo-second order model. Finally, the optimized factors have been applied for uranium(VI) recovery from Gattar leach liquor producing a uranium concentrate (Na2U2O7) with uranium concentration of 70 % and purity of 93.33 %.  相似文献   

11.
In this work, mesoporous hollow silicon spheres modified with 3‐aminopropyl‐ triethoxysilane (APTES) of loaded hydrogen manganese oxide lithium ion sieve (APTES/HMO‐ HS) was prepared. The structure and morphology of as‐prepared APTES/HMO‐HS were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray photoelectron spectroscopy, transmission electron microscopy and nitrogen adsorption‐desorption measurements. The Brunner‐Emmet‐Teller (BET) surface areas, pore diameters and pore volumes of APTES/HMO‐HS decreased gradually, while the Li:Mn:Si molar ratios range from 1:1:50 to 1:1:10. The obtained hierarchical porous APTES/50HMO‐HS has a high specific surface area (557.1694 m2 g‐1). The lithium and rubidium ions solutions were used to measure the adsorption performance of the APTES/HMO‐HS adsorbent. The pseudo‐first‐order and pseudo‐second‐order kinetics, Langmuir and Freundlich isotherms of APTES/HMO‐HS were investigated; suggesting that the adsorption kinetics can be described by the pseudo‐second‐order kinetic model and the adsorption isotherms well fits the Langmuir isotherm equation. The obtained results show that the prepared APTES/HMO‐HS exhibits excellent abilities to simultaneously and selectively recover Li+ and Rb+ (11.22 mg·g‐1 and 8.31 mg·g‐1) and have a promising application in the simultaneous adsorption of lithium and rubidium ions.  相似文献   

12.
In this work, the molecularly imprinted polymers (MIPs) and non-imprinted polymers (NIPs) for clopyralid (3,6-DCP) were successfully synthesized via precipitation polymerization using methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as crosslinker and a mixture of butanone (MEK) and n-heptane as porogen under the existence of azobisisobutyronitrile (AIBN). The morphologies, particle sizes, structures, adsorption properties and selective recognitions of polymers were investigated systematically. The average particle sizes of MIP3 and NIP3 were 2.76 μm and 2.15 μm. The apparent maximum binding amount (Qmax) of MIP3 and NIP3 were 67.50 mg·g?1 and 65.02 mg·g?1 in Scatchard analysis. Langmuir isotherm displayed that the Langmuir constant (Kl) of MIP3 and NIP3 were 0.015 L·mg?1 and 0.0065 L·mg?1, the saturation adsorption capacity (Qmax) of MIP3 and NIP3 were 63.23 mg·g?1 and 58.17 mg·g?1. Lagergren pseudo-second-order kinetic plot described that the adsorption process of MIP3 was visualized as chemical absorption. Selectivity analysis revealed that MIP3 possessed highly specific recognition for 3,6-DCP.  相似文献   

13.
氧化石墨:制备及去除阳离子染料的性能   总被引:2,自引:2,他引:0  
以石墨粉为原料按Hummers氧化法制备氧化石墨,借助X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、傅里叶变换红外光谱法(FTIR)和低温氮吸附-脱附对氧化石墨的结构和形貌进行了表征。结果表明,氧化石墨是不平整的、具有一定层状结构的褶皱片状,在其表面存在着许多含氧的官能团如:环氧基、羟基、羧基。此外还研究了氧化石墨对阳离子染料的吸附性能,结果表明:吸附过程的等温模型符合Langmuir等温式,对甲基紫、甲基绿、中性红这3种阳离子染料的最大饱和吸附量分别为:741,446和368 mg.g-1;对阳离子染料的吸附过程符合二级动力学方程。氧化石墨作为一种吸附剂能有效的去除阳离子染料与其较高的比表面积和与阳离子染料的静电吸引有关。  相似文献   

14.
Alginate beads (ABs) immobilized with hydrous zirconium oxide (ZO) were used as a hybrid adsorbent (ZO@AB) for the effective removal of copper ions [Cu(II)] from aqueous phase. ZO@AB was characterized using X‐ray photoelectron spectroscopy to confirm the impregnation of ABs with ZO and the adsorption of Cu(II) onto ZO@AB. The maximum equilibrium sorption capacity of ZO@AB for Cu(II) was 63.1 mg·g−1 at pH 5. The Cu(II) removal rate was high at the beginning of reaction, with >90% adsorption within 24 hours, and equilibrium was achieved within 48 hours. The adsorption of Cu(II) onto ZO@AB was well described by pseudo‐second‐order kinetic model (R2 > 0.99), and the monolayer nature of sorption was supported by the Langmuir model (R2 > 0.99). The sorption process was endothermic, favorable, and spontaneous in nature. Regarding the reusability of the adsorbent, its sorption capacity remained satisfactory (>90%) throughout the 5 consecutive cycles (regeneration in 0.1 mol·L−1 HCl). The stoichiometric ratio of released calcium ions [Ca(II)] to adsorbed copper ions [Cu(II)] was approximately 1:1, confirming that ion exchange was the main mechanism for removal of Cu(II) from aqueous phase. The developed adsorbent (ZO@AB) shows promise as a candidate for the effective and selective removal of Cu(II) from aqueous phase.  相似文献   

15.
In this study, antimicrobial pigment cinnabarinic acid (CA) was produced from Pycnoporus cinnabarinus in laboratory‐scale batch cultures. Magnetic poly(ethylene glycol dimethacrylate‐N‐methacryloyl‐l‐tryptophan methyl ester) [m‐poly(EGDMA‐MATrp)] beads (average diameter = 53–103 µm) were synthesized by copolymerizing of N‐methacryloyl‐l‐tryptophan methyl ester (MATrp) with ethylene glycol dimethacrylate (EGDMA) in the presence of magnetite (Fe3O4) and used for the adsorption of CA. The m‐poly(EGDMA‐MATrp) beads were characterized by N2 adsorption/desorption isotherms (Brunauer Emmet Teller), X‐ray photoelecron spectroscopy, scanning electron microscopy, infrared spectroscopy, thermal gravimetric analysis, electron spin resonance and swelling studies. The efficiency of m‐poly(EGDMA‐MATrp) beads for separation of CA from culture fluid was evaluated. The effects of pH, initial concentration, contact time and temperature on adsorption were analyzed. The maximum CA adsorption capacity of the m‐poly(EGDMA‐MATrp) beads was 272.9 mg g−1 at pH 7.0, 25 °C. All the isotherm data can be fitted with the Langmuir, Freundlich and Dubinin–Radushkevich isotherm models. The adsorption process obeyed pseudo‐second‐order kinetic model. Thermodynamic parameters ΔH = 5.056 kJ mol−1, ΔS = 52.44 J K−1 mol−1 and ΔG = −9.424 kJ mol−1 to ‐11.27 kJ mol−1 with the rise in temperature from 4 to 40 °C indicated that the adsorption process was endothermic and spontaneous. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

16.
The present study investigates the adsorption capability of raw and biochar forms of Chrysanthemum indicum flowers biomass to remove cobalt ions from aqueous solution in a fixed-bed column. Column adsorption experiments were conducted by varying the bed height (1.0, 2.0, 3.0 cm), flow rate (1.0, 2.5, 5.0 mL min?1) and initial cobalt ion concentration (25, 50, 75 mg L?1) to obtain the experimental breakthrough curves. The adsorption capacity of the raw and biochar forms of C. indicum flowers were found to be 14.84 and 28.34 mg g?1, respectively, for an initial ion concentration of 50 mg L?1 at 1.0 cm bed height and 1.0 mL min?1 flow rate for Co (II) ion adsorption. Adam–Bohart, Thomas and Yoon–Nelson models were applied to the experimental column data to analyze the column performance. The Thomas model was found to best represent the column data with the predicted and experimental uptake capacity values correlating well and with higher R 2 values for all the varying process parameters. Desorption studies revealed the suitability of the adsorbents for repeated use up to four adsorption–desorption cycles without significant loss in its efficiency. It can thus be inferred from the fixed-bed column studies that C. indicum flowers can suitably be used as an effective adsorbent for Co (II) ion removal from aqueous solution on a higher scale.  相似文献   

17.
Adsorption of U(VI) and other heavy metals on millimetre sized polymer-coated polyacrylinitrile (PAN) beads was investigated. PAN was used as scaffolds for the polymer layer thus producing porous material of high surface area, improved mechanical strength and improved adsorption capabilities. Extensive U(VI) adsorption studies were undertaken and results modelled using different kinetic and equilibrium models. Parameters including thermodynamic parameters were evaluated. Sorbent capacities were assessed as 124, 16, and 33 mg g?1 for PCP, SPP and Dowex at 60 °C respectively. U(VI) adsorption mechanism for these adsorbents was postulated. Recovered uranium may be used for production of cheap electricity.  相似文献   

18.
A magnetic adsorbent was synthesized by modification of activated carbons with magnetic iron oxide nanoparticles (AC‐MIONs). The preparation method is fast and could be carried out in an ordinary condition. The AC‐MIONs were used as quite efficient adsorbents for separation of methylene blue (MB) from aqueous solution in a batch process. The effect of different parameters such as pH, temperature, electrolyte concentration, contact time and interfering ions on the removal of MB were studied. The adsorption data were analyzed by Langmuir and Freundlich isotherm models and a maximum adsorption amount of 47.62 mg g‐1 and a langmuir adsorption equilibrium constant of 3.0 L mg‐1 were obtained. The obtained results revealed that AC‐MIONs were effective adsorbents for fast removal of MB from different aqueous solutions. This adsorbent was successfully used for removal of MB from Karoon River water.  相似文献   

19.
《Comptes Rendus Chimie》2015,18(3):261-269
The present work deals with the investigation of the use of synthesized 4A and P1 zeolites in the adsorption of uranium (VI) ions from liquid effluents (with initial concentrations of 100, 85 and 80 mg·L−1). Batch experiments were performed and the effects of temperature, solid–liquid ratio, pH and initial UO22+ ion concentration were studied, and the optimal parameters were determined. The kinetic and thermodynamic aspects of the process as well as the diffusion mechanism have been studied. The obtained results showed that 4A and P1 zeolites are very effective adsorbents.  相似文献   

20.
A significant synergic effect between a metal–organic framework (MOF) and Fe2SO4, the so‐called MOF+ technique, is exploited for the first time to remove toxic chromate from aqueous solutions. The results show that relative to the pristine MOF samples (no detectable chromate removal), the MOF+ method enables super performance, giving a 796 Cr mg g−1 adsorption capacity. The value is almost eight‐fold higher than the best value of established MOF adsorbents, and the highest value of all reported porous adsorbents for such use. The adsorption mechanism, unlike the anion‐exchange process that dominates chromate removal in all other MOF adsorbents, as unveiled by X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), is due to the surface formation of Fe0.75Cr0.25(OH)3 nanospheres on the MOF samples.  相似文献   

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