The catalysis of olefin polymerization through the chain-walking process is a subject of great interest. In this contribution, the successful synthesis of a Brookhart-type unsymmetrical α-diimine nickel catalyst Ni, ...The catalysis of olefin polymerization through the chain-walking process is a subject of great interest. In this contribution, the successful synthesis of a Brookhart-type unsymmetrical α-diimine nickel catalyst Ni, which contains both dibenzhydryl and phenyl groups, was determined by X-ray crystallography. The compound has a pseudo-tetrahedral geometry at the Ni center, showing pseudo-C2-symmetry. Upon activation with modified methylaluminoxane (MMAO), Ni1 exhibits high catalytic activity up to 1.02 × 107 g PE (mol Ni h)−1 toward ethylene polymerization, enabling the synthesis of high molecular weight branched polyethylene. The molecular weights and branching densities could be tuned over a very wide range. The polymerization results indicated the possibility of precise microstructure control, depending on the polymerization temperature. The branching densities were decreased with increasing the polymerization temperature.展开更多
通过对超声波传感器温度分布测量技术的研究了解,我们发现其作为一种非接触式测温方式,在高温、高腐蚀等恶劣环境中具有广泛的应用。超声波传播速度和衰减量可用于计算被测物体内部的温度分布,实现温度测量。相比传统的接触式测温法,超...通过对超声波传感器温度分布测量技术的研究了解,我们发现其作为一种非接触式测温方式,在高温、高腐蚀等恶劣环境中具有广泛的应用。超声波传播速度和衰减量可用于计算被测物体内部的温度分布,实现温度测量。相比传统的接触式测温法,超声测温法无需与被测对象直接接触,避免了传感器受到高温环境影响的问题,因此提高了测量的精度,并扩大了测温范围和深度。基于此,本文进行了NI ELVIS II+平台的超声波传感器温度分布测量技术研究,超声波传感器温度分布测量原理分析。本文得到了气体介质的温度和声波速度之间的函数关系,并据此建立了声学测温模型,从而实现温度的准确测量和检测。超声波温度检测系统的总体设计。根据相关的技术指标,对相关测温原理进行详细分析,对相位差法和飞行时间法两种测温方案进行了深入阐述,并且比较两种方案的优缺点及适用范围,在此基础上提出了基于相位差法的设计方案,依据此,最终给出系统总体设计方案。展开更多
PS-PAMAM-IDA chelating resins were prepared by low-generations of polyamidoamine(PAMAM) and then chloroacetic acid functionalizing commercially available ammoniated polystyrene matrix, to preconcentrate Ni2+ from synt...PS-PAMAM-IDA chelating resins were prepared by low-generations of polyamidoamine(PAMAM) and then chloroacetic acid functionalizing commercially available ammoniated polystyrene matrix, to preconcentrate Ni2+ from synthetic aqueous samples. Different generations of PAMAM were used to obtain different chelating resins, PS-IDA, PS-1.0G PAMAM-IDA and PS-2.0G PAMAM-IDA. The synthesized resins were characterized by FTIR and elemental analysis. The effect of solution pH, kinetic studies, resin loading capacity, matrix effects etc., on metal ion adsorption to adsorbent phase, were studied by batch method. The PS-1.0G PAMAM-IDA resin was the most excellent adsorbents, with a maximum adsorption capacity of(24.09±1.79) mg/g for Ni2+ ion at pH=7. The interpretation of the equilibrium data was given by Langmuir isotherms model, and the correlation coefficient values for PS-IDA, PS-1.0G PAMAM-IDA and PS-2.0G PAMAM-IDA resins were 0.992, 0.994 and 0.987, respectively.展开更多
A single-layer Artificial Neural Network (ANN) model was developed to predict the removal efficiency of Ni(II) ions from aqueous solution using shelled Moringa Oleifera seed (SMOS) powder. Batch experiments resulted i...A single-layer Artificial Neural Network (ANN) model was developed to predict the removal efficiency of Ni(II) ions from aqueous solution using shelled Moringa Oleifera seed (SMOS) powder. Batch experiments resulted into standardization of optimum conditions: biomass dosage (4.0 g), Ni(II) concentration (25 mg/L) volume (200 mL) at pH 6.5. A time of forty minutes was found sufficient to achieve the equilibrium. The ANN model was designed to predict sorption efficiency of SMOS for target metal ion by combining back propagation (BP) with principle component analysis. A sigmoid axon was used as transfer function for input and output layers. The Levenberg–Marquardt Algorithm (LMA) was applied, giving a minimum mean squared error (MSE) for training and cross validation at the ninth place of decimal.展开更多
Chemical compositions of natural zeolites, porcelanite (opal-CT) and local sands were determined by X-ray fluorescence (XRF) and correlated with their Pb(II) removal efficiencies. Zeolites and porcelanite were from th...Chemical compositions of natural zeolites, porcelanite (opal-CT) and local sands were determined by X-ray fluorescence (XRF) and correlated with their Pb(II) removal efficiencies. Zeolites and porcelanite were from the Mikawer, Aritain and Hannon areas in Jordan. Sands (white, red and yellow) were from the United Arab Emirates (UAE). The effect of Pb(II) concentration and zeolite dosage on removal efficiency was investigated at 25.0°C using the batch equilibrium method. Commercial kaolinite, silica and alumina were also studied for comparison. Removal efficiencies, in mg Pb(II)/g adsorbent, were: 76.9, 52.7 and 42.1 for Hannon, Mikawer and Aritain zeolites, respectively;58.2 for porcelanite;29.7, 11.0 and 8.5 for yellow, red and white sand, respectively;7.2, 3.3 and 1.3 for kaolinite, silica and alumina, respectively. XRF data indicate that adsorbents with intermediate molar ratios of Si/Al, in the range 2.70 - 2.93, are most efficient in Pb(II) removal. Scanning electron microscope (SEM) images of adsorbents suggest that morphology, in addition to chemical composition, plays a key role. In particular, a combination of factors, including shapes and sizes of crystals, channels in zeolites and pores in porcelanite, appear to favor removal of Pb(II).展开更多
Sawdust (SD) a very low cost material has been utilized as adsorbent material for the removal of Cd (II) from aqueous solutions after treatment with mono methylol urea (MMU) in the presence of zinc chloride as a catal...Sawdust (SD) a very low cost material has been utilized as adsorbent material for the removal of Cd (II) from aqueous solutions after treatment with mono methylol urea (MMU) in the presence of zinc chloride as a catalyst to form MMU-SD. The reaction of MMU-SD was carried out under different conditions including MMU/SD molar ratio, catalyst concentration, and reaction time and temperature. Adsorption studies have been carried out to determine the effect of agitation time, pH, adsorbent and adsorbate concentrations on the adsorption capacity of Cd (II) ions onto MMU-SD. Langmuir, Freundlich and Redlich-Peterson isotherm models were applied in the adsorption studies. The experimental data were analyzed using various sorption kinetic models. The removal processes of Cd (II) onto MMU-SD particles could be well described by the pseudo-second order model. The maximum adsorption capacity of Cd(II) onto MMU-SD was 909 mg/g. Similarly, the Freundlich constant 1/n value was 0.45.展开更多
A new Ni(II) coordination polymer [Ni(L)2(SCN)2]n(L = 1,4-bis(benzimidazol-1-yl)butane) was synthesized hydrothermally and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The...A new Ni(II) coordination polymer [Ni(L)2(SCN)2]n(L = 1,4-bis(benzimidazol-1-yl)butane) was synthesized hydrothermally and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group C2/c with a = 9.4760(3), b = 24.0408(8), c = 16.5871(5) A, β = 99.832(3)°, V = 3723.2(2) A3, Z = 4, Dc = 1.348 g/cm3, F(000) = 1576, the final R = 0.0486 and w R = 0.0936 for 2938 observed reflections with I 】 2σ(I) for the complex. Structural analysis shows that the coordination polymer possesses a 2D(4,4) layer structure which is composed of Ni(II) centers bridged by L ligand with two kinds of conformations and further assembled into a 3D supramolecular network via π-π stacking interactions. In addition, the fluorescence and catalytic properties, for the degradation of Congo red, of the complex were investigated.展开更多
This work examined the removal of Pb(II) using a chitosan derivative (SB, synthesized from benzaldehyde) assisted by a magnetic field. The adsorption capacity for Pb(II) was investigated. It was found that 1) the pH a...This work examined the removal of Pb(II) using a chitosan derivative (SB, synthesized from benzaldehyde) assisted by a magnetic field. The adsorption capacity for Pb(II) was investigated. It was found that 1) the pH and concentration of the ion solution, as well as exposure time and strength of magnetic field, affected the degree of adsorption;and 2) studies of the adsorption isotherms and kinetics of ions onto SB revealed that SB showed enhanced adsorption capacity towards Pb(II) ions in a magnetic field compared with magnetically untreated samples. The Langmuir and Freundlich isotherm were applied to describe the experimental adsorption, and the maximum adsorption capacity of SB for Pb(II) was 2.5040 mg/g, when assisted by a magnetic field of 480 kA/m.展开更多
A new nanometer material,nanometer AlO(OH)loaded on the fiberglass with activated carbon fibersfelt(ACF)as the carrier,was prepared by hydrolytic reaction for the removal of Cd(II)from aqueous solution usingcolumn ads...A new nanometer material,nanometer AlO(OH)loaded on the fiberglass with activated carbon fibersfelt(ACF)as the carrier,was prepared by hydrolytic reaction for the removal of Cd(II)from aqueous solution usingcolumn adsorption experiment.As was confirmed by XRD determination,the hydrolysis production loaded on fi-berglass was similar to the orthorhombic phase AlO(OH).SEM images showed that AlO(OH)particles were in theform of small aggregated clusters.The Thomas model was applied for estimating the kinetic parameters and thesaturated adsorption ability of Cd(II)adsorption on the new adsorbent.The results showed that the maximum ad-sorption capacity of Cd(II)was 128.50 mg·g-1and 117.86 mg·g-1for the adsorbent mass of 0.3289 g and the ad-sorbent mass of 0.2867 g,respectively.The elution experiment result indicated that the adsorbed Cd ions was easilydesorbed from the material with 0.1 mol·L-1HCl solution.Adsorption-desorption cycles showed the feasibility ofrepeated uses of the composited material.The adsorption capacities were influenced by pH and the initial Cd(II)concentration.The amount adsorbed was greatest at pH 6.5 and the initial Cd(II)concentration of 0.07 mg·L-1,re-spectively.Nanometer AlO(OH)played a major role in the adsorption process,whereas the fiberglass and ACFwere assistants in the process of removing Cd(II).In addition,the adsorption capacities for Cd(II)were obviouslyreduced from 128.50 mg·g-1to 64.28 mg·g-1when Pb ions were present because Pb ions took up more adsorption sites.展开更多
The title compound, [Ni（tssb）（2,2-bipy）2].5（H2O） 1 （tssbH2 =2-[（E）-（2-oxido- phenyl）methyleneamino]ethanesulfonato, 2,2-bipy = 2,2＇-bipyridinyl）, belongs to orthorhombic, space group Pbcn with a = 20.3983...The title compound, [Ni（tssb）（2,2-bipy）2].5（H2O） 1 （tssbH2 =2-[（E）-（2-oxido- phenyl）methyleneamino]ethanesulfonato, 2,2-bipy = 2,2＇-bipyridinyl）, belongs to orthorhombic, space group Pbcn with a = 20.3983（18）, b = 17.6929（15）, c = 17.0897（15） nm, V= 6167.8（9） nm^3, Mr= 688.38, Z = 8, De = 1.481 g.cm^-3, F（000） = 2880,μ = 0.758 mm-1 and S =1.099. Each NiIr atom is six-coordinated by one N and one O atoms from one tssb^2- anion and four N atoms from two 2,2-bipy ligands to give a distorted octahedral geometry. Noticeably, there exists a rare octa-mem- bered water ring which presents a 1D chain by sulfonic group.展开更多
The Ni-B-Oδ and Ni-B-Zr-Oδ catalysts were prepared by the method of chemical reduction, and the deep removal of CO by selective methanation from the reformed fuels was performed over the as-prepared catalysts. The r...The Ni-B-Oδ and Ni-B-Zr-Oδ catalysts were prepared by the method of chemical reduction, and the deep removal of CO by selective methanation from the reformed fuels was performed over the as-prepared catalysts. The results showed that zirconium strongly influenced the activity and selectivity of the Ni-B-Zr-Oδ catalysts. Over the Ni-B-Oδ catalyst, the highest CO conversion obtained was only 24.32% under the experi-mental conditions studied. However, over the Ni-B-Zr-Oδ catalysts, the CO methanation conversion was higher than 90% when the temperature was increased to 220℃. Additionally, it was found that the Ni/B mole ratio also affected the performance of the Ni-B-Zr-Oδ catalysts. With the increase of the Ni/B mole ratio from 1.8 to 2.2, the CO methanation activity of the catalyst was improved. But when the Ni/B mole ratio was higher than 2.2, the performance of the catalyst for CO selective methanation decreased instead. Among all the catalysts, the Ni29B13Zr58Oδ catalyst investigated here exhibited the highest catalytic performance for the CO selective methanation, which was capable of reducing the CO outlet concentration to less than 40 ppm from the feed gases stream in the temperature range of 230-250℃, while the CO2 conversion was kept below 8% all along. Characterization of the Ni-B-Oδ and Ni-B-Zr-Oδ catalysts was provided by XRD, SEM, DSC, and XPS.展开更多
The present study is aimed to examine the adsorption characteristics of Cu(II) by using the novel cellulose acetate composite and to apply it for the removal of Cu(II) from real wastewater samples. In order to achieve...The present study is aimed to examine the adsorption characteristics of Cu(II) by using the novel cellulose acetate composite and to apply it for the removal of Cu(II) from real wastewater samples. In order to achieve this objective, ethylenediamine, diethylenetriamine, triethylenetetramine and te-traethylenepentanene were used for immobilization of grafted cellulose acetate-nanoscale manganese dioxide. Cellulose was extracted from mangrove species Avicennia marina and converted to cellulose acetate then it was formed composite with nano-manganese dioxide via precipitation of nano-manganese dioxide on it. The composite was grafted with acrylamide monomer before immobilization. The synthesized compounds were used for adsorption of Cu(II) and characterized by FT-IR, TGA and SEM. The adsorption characteristics of synthesized sorbents were optimized. Langmuir and Freundlich models were used to establish sorption equilibria. The analytical applications of these modified materials were applied successfully for the removal of Cu(II).展开更多
In this work, the synthesis and complexation properties of a new compound, 1,3-bis[5-(2-hydroxyphenyl)-4-phenyl- 1,2,4-triazole-3-yl-thio]propane (BTP), towards certain transition metal ions, (M(II) where M = Zn, Cu, ...In this work, the synthesis and complexation properties of a new compound, 1,3-bis[5-(2-hydroxyphenyl)-4-phenyl- 1,2,4-triazole-3-yl-thio]propane (BTP), towards certain transition metal ions, (M(II) where M = Zn, Cu, Ni) in acetonitrile is reported. A hard-modeling strategy was applied to UV-Visible spectroscopy data obtained from monitoring the reaction between BTP and the selected metal ions to determine the concentration profiles of each species and the corresponding stability constant(s) of the complex(es). The stability constants of complexes are always defined in terms of their free metal, free ligand and complexed forms. These constants are influenced by parameters such as the type of metal, ligand, counterion or solvent. In this study, the formation constants of the complexes were determined for the synthesized ligand with several metallic cations in acetonitrile solvent by UV-Vis spectrophotometry.展开更多
Cornulaca monacantha (CM) a desert plant has been utilized as adsorbent material for the removal of Hg (II) ions from contaminated water after treatment with acrylamide in alkaline medium to form carbamoylethylated Co...Cornulaca monacantha (CM) a desert plant has been utilized as adsorbent material for the removal of Hg (II) ions from contaminated water after treatment with acrylamide in alkaline medium to form carbamoylethylated Cornulaca monacantha (CECM). Three levels of CECM having different nitrogen content were prepared. The CECM samples were characterized by estimating the nitrogen content. The ability of CECM to adsorb Hg (II) was investigated by using batch adsorption procedure. The data of the adsorption isotherm was tested by the Langmuir, Freundlich and Temkin models. The removal of Hg (II) onto CECM particles could be well described by the pseudo-second order model. The adsorption rate of mercury was affected by the initial Hg (II) ion concentration, initial pH, adsorbent concentration and agitation time as well as extent of modification. The adsorption experiments indicated that the CECM particles have great potential for the removal of Hg (II) from contaminated water. The maximum adsorption capacity, Qmax of the CECM towards Hg (II) ions was found to be 384.6 mg/g at 30?C. Similarly, the Freundlich constant, n was found to be 2.03 at 30°C.展开更多
文摘The catalysis of olefin polymerization through the chain-walking process is a subject of great interest. In this contribution, the successful synthesis of a Brookhart-type unsymmetrical α-diimine nickel catalyst Ni, which contains both dibenzhydryl and phenyl groups, was determined by X-ray crystallography. The compound has a pseudo-tetrahedral geometry at the Ni center, showing pseudo-C2-symmetry. Upon activation with modified methylaluminoxane (MMAO), Ni1 exhibits high catalytic activity up to 1.02 × 107 g PE (mol Ni h)−1 toward ethylene polymerization, enabling the synthesis of high molecular weight branched polyethylene. The molecular weights and branching densities could be tuned over a very wide range. The polymerization results indicated the possibility of precise microstructure control, depending on the polymerization temperature. The branching densities were decreased with increasing the polymerization temperature.
文摘通过对超声波传感器温度分布测量技术的研究了解,我们发现其作为一种非接触式测温方式,在高温、高腐蚀等恶劣环境中具有广泛的应用。超声波传播速度和衰减量可用于计算被测物体内部的温度分布,实现温度测量。相比传统的接触式测温法,超声测温法无需与被测对象直接接触,避免了传感器受到高温环境影响的问题,因此提高了测量的精度,并扩大了测温范围和深度。基于此,本文进行了NI ELVIS II+平台的超声波传感器温度分布测量技术研究,超声波传感器温度分布测量原理分析。本文得到了气体介质的温度和声波速度之间的函数关系,并据此建立了声学测温模型,从而实现温度的准确测量和检测。超声波温度检测系统的总体设计。根据相关的技术指标,对相关测温原理进行详细分析,对相位差法和飞行时间法两种测温方案进行了深入阐述,并且比较两种方案的优缺点及适用范围,在此基础上提出了基于相位差法的设计方案,依据此,最终给出系统总体设计方案。
基金Project(51074192)supported by the National Natural Science Foundation of China
文摘PS-PAMAM-IDA chelating resins were prepared by low-generations of polyamidoamine(PAMAM) and then chloroacetic acid functionalizing commercially available ammoniated polystyrene matrix, to preconcentrate Ni2+ from synthetic aqueous samples. Different generations of PAMAM were used to obtain different chelating resins, PS-IDA, PS-1.0G PAMAM-IDA and PS-2.0G PAMAM-IDA. The synthesized resins were characterized by FTIR and elemental analysis. The effect of solution pH, kinetic studies, resin loading capacity, matrix effects etc., on metal ion adsorption to adsorbent phase, were studied by batch method. The PS-1.0G PAMAM-IDA resin was the most excellent adsorbents, with a maximum adsorption capacity of(24.09±1.79) mg/g for Ni2+ ion at pH=7. The interpretation of the equilibrium data was given by Langmuir isotherms model, and the correlation coefficient values for PS-IDA, PS-1.0G PAMAM-IDA and PS-2.0G PAMAM-IDA resins were 0.992, 0.994 and 0.987, respectively.
文摘A single-layer Artificial Neural Network (ANN) model was developed to predict the removal efficiency of Ni(II) ions from aqueous solution using shelled Moringa Oleifera seed (SMOS) powder. Batch experiments resulted into standardization of optimum conditions: biomass dosage (4.0 g), Ni(II) concentration (25 mg/L) volume (200 mL) at pH 6.5. A time of forty minutes was found sufficient to achieve the equilibrium. The ANN model was designed to predict sorption efficiency of SMOS for target metal ion by combining back propagation (BP) with principle component analysis. A sigmoid axon was used as transfer function for input and output layers. The Levenberg–Marquardt Algorithm (LMA) was applied, giving a minimum mean squared error (MSE) for training and cross validation at the ninth place of decimal.
文摘Chemical compositions of natural zeolites, porcelanite (opal-CT) and local sands were determined by X-ray fluorescence (XRF) and correlated with their Pb(II) removal efficiencies. Zeolites and porcelanite were from the Mikawer, Aritain and Hannon areas in Jordan. Sands (white, red and yellow) were from the United Arab Emirates (UAE). The effect of Pb(II) concentration and zeolite dosage on removal efficiency was investigated at 25.0°C using the batch equilibrium method. Commercial kaolinite, silica and alumina were also studied for comparison. Removal efficiencies, in mg Pb(II)/g adsorbent, were: 76.9, 52.7 and 42.1 for Hannon, Mikawer and Aritain zeolites, respectively;58.2 for porcelanite;29.7, 11.0 and 8.5 for yellow, red and white sand, respectively;7.2, 3.3 and 1.3 for kaolinite, silica and alumina, respectively. XRF data indicate that adsorbents with intermediate molar ratios of Si/Al, in the range 2.70 - 2.93, are most efficient in Pb(II) removal. Scanning electron microscope (SEM) images of adsorbents suggest that morphology, in addition to chemical composition, plays a key role. In particular, a combination of factors, including shapes and sizes of crystals, channels in zeolites and pores in porcelanite, appear to favor removal of Pb(II).
文摘Sawdust (SD) a very low cost material has been utilized as adsorbent material for the removal of Cd (II) from aqueous solutions after treatment with mono methylol urea (MMU) in the presence of zinc chloride as a catalyst to form MMU-SD. The reaction of MMU-SD was carried out under different conditions including MMU/SD molar ratio, catalyst concentration, and reaction time and temperature. Adsorption studies have been carried out to determine the effect of agitation time, pH, adsorbent and adsorbate concentrations on the adsorption capacity of Cd (II) ions onto MMU-SD. Langmuir, Freundlich and Redlich-Peterson isotherm models were applied in the adsorption studies. The experimental data were analyzed using various sorption kinetic models. The removal processes of Cd (II) onto MMU-SD particles could be well described by the pseudo-second order model. The maximum adsorption capacity of Cd(II) onto MMU-SD was 909 mg/g. Similarly, the Freundlich constant 1/n value was 0.45.
基金supported by the Starting Research Fund from Hebei United University(35398599)the Natural Science Foundation of Hebei Province(B2014209182)
文摘A new Ni(II) coordination polymer [Ni(L)2(SCN)2]n(L = 1,4-bis(benzimidazol-1-yl)butane) was synthesized hydrothermally and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group C2/c with a = 9.4760(3), b = 24.0408(8), c = 16.5871(5) A, β = 99.832(3)°, V = 3723.2(2) A3, Z = 4, Dc = 1.348 g/cm3, F(000) = 1576, the final R = 0.0486 and w R = 0.0936 for 2938 observed reflections with I 】 2σ(I) for the complex. Structural analysis shows that the coordination polymer possesses a 2D(4,4) layer structure which is composed of Ni(II) centers bridged by L ligand with two kinds of conformations and further assembled into a 3D supramolecular network via π-π stacking interactions. In addition, the fluorescence and catalytic properties, for the degradation of Congo red, of the complex were investigated.
文摘This work examined the removal of Pb(II) using a chitosan derivative (SB, synthesized from benzaldehyde) assisted by a magnetic field. The adsorption capacity for Pb(II) was investigated. It was found that 1) the pH and concentration of the ion solution, as well as exposure time and strength of magnetic field, affected the degree of adsorption;and 2) studies of the adsorption isotherms and kinetics of ions onto SB revealed that SB showed enhanced adsorption capacity towards Pb(II) ions in a magnetic field compared with magnetically untreated samples. The Langmuir and Freundlich isotherm were applied to describe the experimental adsorption, and the maximum adsorption capacity of SB for Pb(II) was 2.5040 mg/g, when assisted by a magnetic field of 480 kA/m.
文摘A new nanometer material,nanometer AlO(OH)loaded on the fiberglass with activated carbon fibersfelt(ACF)as the carrier,was prepared by hydrolytic reaction for the removal of Cd(II)from aqueous solution usingcolumn adsorption experiment.As was confirmed by XRD determination,the hydrolysis production loaded on fi-berglass was similar to the orthorhombic phase AlO(OH).SEM images showed that AlO(OH)particles were in theform of small aggregated clusters.The Thomas model was applied for estimating the kinetic parameters and thesaturated adsorption ability of Cd(II)adsorption on the new adsorbent.The results showed that the maximum ad-sorption capacity of Cd(II)was 128.50 mg·g-1and 117.86 mg·g-1for the adsorbent mass of 0.3289 g and the ad-sorbent mass of 0.2867 g,respectively.The elution experiment result indicated that the adsorbed Cd ions was easilydesorbed from the material with 0.1 mol·L-1HCl solution.Adsorption-desorption cycles showed the feasibility ofrepeated uses of the composited material.The adsorption capacities were influenced by pH and the initial Cd(II)concentration.The amount adsorbed was greatest at pH 6.5 and the initial Cd(II)concentration of 0.07 mg·L-1,re-spectively.Nanometer AlO(OH)played a major role in the adsorption process,whereas the fiberglass and ACFwere assistants in the process of removing Cd(II).In addition,the adsorption capacities for Cd(II)were obviouslyreduced from 128.50 mg·g-1to 64.28 mg·g-1when Pb ions were present because Pb ions took up more adsorption sites.
基金Supported by the Key Laboratory of Non-ferrous Metal Materials and New Processing TechnologyMinistry of Education and the State Key Laboratory of Coordination Chemistry
文摘The title compound, [Ni（tssb）（2,2-bipy）2].5（H2O） 1 （tssbH2 =2-[（E）-（2-oxido- phenyl）methyleneamino]ethanesulfonato, 2,2-bipy = 2,2＇-bipyridinyl）, belongs to orthorhombic, space group Pbcn with a = 20.3983（18）, b = 17.6929（15）, c = 17.0897（15） nm, V= 6167.8（9） nm^3, Mr= 688.38, Z = 8, De = 1.481 g.cm^-3, F（000） = 2880,μ = 0.758 mm-1 and S =1.099. Each NiIr atom is six-coordinated by one N and one O atoms from one tssb^2- anion and four N atoms from two 2,2-bipy ligands to give a distorted octahedral geometry. Noticeably, there exists a rare octa-mem- bered water ring which presents a 1D chain by sulfonic group.
基金the National Natural Science Foundation of China (20576023)the Guangdong Province Natural Science Foundation (06025660)
文摘The Ni-B-Oδ and Ni-B-Zr-Oδ catalysts were prepared by the method of chemical reduction, and the deep removal of CO by selective methanation from the reformed fuels was performed over the as-prepared catalysts. The results showed that zirconium strongly influenced the activity and selectivity of the Ni-B-Zr-Oδ catalysts. Over the Ni-B-Oδ catalyst, the highest CO conversion obtained was only 24.32% under the experi-mental conditions studied. However, over the Ni-B-Zr-Oδ catalysts, the CO methanation conversion was higher than 90% when the temperature was increased to 220℃. Additionally, it was found that the Ni/B mole ratio also affected the performance of the Ni-B-Zr-Oδ catalysts. With the increase of the Ni/B mole ratio from 1.8 to 2.2, the CO methanation activity of the catalyst was improved. But when the Ni/B mole ratio was higher than 2.2, the performance of the catalyst for CO selective methanation decreased instead. Among all the catalysts, the Ni29B13Zr58Oδ catalyst investigated here exhibited the highest catalytic performance for the CO selective methanation, which was capable of reducing the CO outlet concentration to less than 40 ppm from the feed gases stream in the temperature range of 230-250℃, while the CO2 conversion was kept below 8% all along. Characterization of the Ni-B-Oδ and Ni-B-Zr-Oδ catalysts was provided by XRD, SEM, DSC, and XPS.
文摘The present study is aimed to examine the adsorption characteristics of Cu(II) by using the novel cellulose acetate composite and to apply it for the removal of Cu(II) from real wastewater samples. In order to achieve this objective, ethylenediamine, diethylenetriamine, triethylenetetramine and te-traethylenepentanene were used for immobilization of grafted cellulose acetate-nanoscale manganese dioxide. Cellulose was extracted from mangrove species Avicennia marina and converted to cellulose acetate then it was formed composite with nano-manganese dioxide via precipitation of nano-manganese dioxide on it. The composite was grafted with acrylamide monomer before immobilization. The synthesized compounds were used for adsorption of Cu(II) and characterized by FT-IR, TGA and SEM. The adsorption characteristics of synthesized sorbents were optimized. Langmuir and Freundlich models were used to establish sorption equilibria. The analytical applications of these modified materials were applied successfully for the removal of Cu(II).
文摘In this work, the synthesis and complexation properties of a new compound, 1,3-bis[5-(2-hydroxyphenyl)-4-phenyl- 1,2,4-triazole-3-yl-thio]propane (BTP), towards certain transition metal ions, (M(II) where M = Zn, Cu, Ni) in acetonitrile is reported. A hard-modeling strategy was applied to UV-Visible spectroscopy data obtained from monitoring the reaction between BTP and the selected metal ions to determine the concentration profiles of each species and the corresponding stability constant(s) of the complex(es). The stability constants of complexes are always defined in terms of their free metal, free ligand and complexed forms. These constants are influenced by parameters such as the type of metal, ligand, counterion or solvent. In this study, the formation constants of the complexes were determined for the synthesized ligand with several metallic cations in acetonitrile solvent by UV-Vis spectrophotometry.
文摘Cornulaca monacantha (CM) a desert plant has been utilized as adsorbent material for the removal of Hg (II) ions from contaminated water after treatment with acrylamide in alkaline medium to form carbamoylethylated Cornulaca monacantha (CECM). Three levels of CECM having different nitrogen content were prepared. The CECM samples were characterized by estimating the nitrogen content. The ability of CECM to adsorb Hg (II) was investigated by using batch adsorption procedure. The data of the adsorption isotherm was tested by the Langmuir, Freundlich and Temkin models. The removal of Hg (II) onto CECM particles could be well described by the pseudo-second order model. The adsorption rate of mercury was affected by the initial Hg (II) ion concentration, initial pH, adsorbent concentration and agitation time as well as extent of modification. The adsorption experiments indicated that the CECM particles have great potential for the removal of Hg (II) from contaminated water. The maximum adsorption capacity, Qmax of the CECM towards Hg (II) ions was found to be 384.6 mg/g at 30?C. Similarly, the Freundlich constant, n was found to be 2.03 at 30°C.
