Adsorption of Lead(II),Copper(II) on tourmaline from Altai mine in China's Sinkiang

Tourmaline from Altai mine in China＇s Sinkiang was used to remove lead （II）, copper （II） from aqueous solution. The results demonstrate that tourmaline contains Na（Mg,V）3AI6（BO3）3Si6Ols （OH）4, NaFe3AI6（BO3）3Si6Ols（OH）4. The data show that Tourmaline from Altai mine in China＇s Sinkiang can be used natural adsorbent for lead （II）, copper （II）.It is observed that the adsorption data fitted to the Langmuir isotherm. Furthermore, both Pb （II） and Cu （II） absorbed by tourmaline and tourmaline were characterized by X-ray diffraction, Laser Raman Spectrum, Fourier transform infrared spectroscopy, X-ray energy dispersive spectrometer, Transmission electron microscopy and Zeta potential.

Evaluation of Biosorptive Capacity of Banana (<i>Musa paradisiaca</i>) Stalk for Lead(II) Removal from Aqueous Solution

Raw Banana Stalk (RBS), Acid Activated Banana Stalk (AABS) and Base Activated Banana Stalk (BABS) prepared from banana stalk were used as biosorbents to remove Lead(II) from aqueous solution. The biosorbents were characterised using proximate analysis and Fourier Transform Infrared (FTIR) spectroscopy. Pb(II) of 1000 mg/L concentration was prepared from Pb(NO3)2 salt and other concentrations were obtained from this stock through serial dilution. Effects of adsorbent dose, temperature, initial metal concentration, contact time and pH on the percentage Pb(II) removal were evaluated. The Pb(II) concentrations in the solutions were analysed using Atomic Absorption Spectrophotometer. Kinetic, isotherm and thermodynamic parameters were determined. FTIR spectroscopy showed that RBS, AABS and BABS are rich in carboxyl, hydroxyl and phenolic functional groups. At an equilibrium time of 180 minutes, the percentage Pb(II) removal was 63.97%, 96.13% and 66.90% for RBS, AABS and BABS, respectively. Pseudo-second order kinetics best described the process with R2 (0.95, 0.98, 0.97) for RBS, AABS and BABS, respectively. Langmuir isotherm (AABS) has the maximum adsorption capacity (qmax) of 13.53 mg/g and R2 (0.99). Thermodynamic parameters obtained were △G0 (?18.75 kJ/mol), △H0 (12.63 kJ/mol), △S0 (0.05 kJ/mol·K) and Ea (4.37 kJ/mol). Banana stalk has viable characteristics for preparing biosorbents. Acid activated banana biosorbent is more efficient for removal of lead ions from its aqueous solution.

Bioremediation of Lead(II) from Polluted Wastewaters Employing Sulphuric Acid Treated Maize Tassel Biomass

The ability to modify a waste by-product precursor, maize tassel biomass using sulfuric acid as the activating agent with specific focus on Lead(II) ion from water has been proposed. The treating of maize tassel using sulphuric acid is believed to enhance sorption capacity of Lead(II) ions. For this, batch adsorption mode was adopted for which the effects of initial pH, adsorbent dosage, contact time and initial concentration were investigated. Consequently, it was found that the adsorbent capacity depends on pH;since it increases up to 4.5 and then decreases. The highest percentage of Lead(II) ion removal was achieved in the adsorbent dosage of 1.2 g and at an initial concentration of 10 mg/L metal ion. In an attempt to determine the capacity and rate of Lead(II) removal, isotherm and kinetic data were modeled using appropriate equations. To this end, the adsorption data fitted best into the Langmuir model with an R2 (0.9997) while kinetically the Lead(II) adsorption followed the pseudo-second-order model. Furthermore, as a way to address issues related to sustainability, maize tassel is recommended since the process is considered to be a dual solution for environmental cleaning. From one side, it represents a better way to dispose the maize tassel which has no use after fertilization and on the other hand it is an economic source of carbonaceous materials.

Determination of Lead(II) in Liver Corpse of a Slaughtered Cattle with Preconcentration on a Chelating Sorbent

The copolymer of the maleic anhydride-styrene is modified at the presence of 4-amino-2-thiouracil and formaldehyde and the new polymeric sorbate with spatial structure is received. The received sorbate is identified by the IR-spectroscopy method. The complete static sorption capacitance was studied (CSSC+K= 7.8 mmol/g) and the ionization constants of ionic groups in a sorbate link was defined by electrometric method. Ionization constants were determined by potentiometric titration of the sorbent (). Sorption and desorption of the received sorbent with a lead ion (II) are investigated and optimum concentration conditions are defined: рНopt. = 5, ionic force μ = 0.8 pier/l, full sorption balance 4 hours, optimum eluent 5 ml of 0.5 M HCl.

ERP/MRP-II系统动态提前期的研究

在ERP/MRP -II系统中 ,提前期是一个与交货期、库存计划、能力平衡计划等等参数和过程有着密切关系的变量。可以说 ,提前期在ERP/MRP -II系统中具有核心地位。因此提前期的确定也就显得非常重要。从决定提前期的相关因素入手 ,利用神经网络模型 。

基于神经网络动态确定ERP/MRP-II系统提前期的研究

在ERP MRP -II系统中 ,提前期是一个与开发期、交货期、库存计划、能力平衡计划等参数和过程有着密切关系的变量。可以说 ,提前期在ERP MRP -II系统中具有核心地位。因此提前期的确定也就显得非常重要。本文试图从决定提前期的相关因素入手 ,利用神经网络模型 ,确定出能够根据生产条件、环境而改变的动态提前期。

Hydrothermal Synthesis and Crystal Structure of a Lead(Ⅱ) Polymer with a Two-dimensional Network Structure:[Pb_2(PDB)_2(phen)]_n·nH_2O

A new metal-organic complex [Pb2（PDB）2（phen）]n·nH2O （H2PDB=pyridine-3,4-dicarboxylic acid,phen=1,10-phenanthroline） 1 has been hydrothermally synthesized and structurally characterized by elemental analysis,IR spectrum,TG and single-crystal X-ray diffraction.The compound crystallizes in triclinic,space group P1 with a=7.2472（5）,b=10.6966（8）,c=16.2376（12）,α=98.2960（10）,β=91.6430（10）,γ=97.4810（10）o,V=1233.53（16）3,C26H16O9N4Pb2,Mr=942.81,Dc=2.538 g/cm3,μ（MoKα）=13.697 mm-1,F（000）=872,Z=2,the final R=0.0247 and wR=0.0654 for 3886 observed reflections （I 〉 2σ（I））.In the crystal structure,the Pb（1） atom is six-coordinated with four carboxylate oxygen atoms from three different PDB ligands and two nitrogen atoms from phen ligand,showing a distorted octahedral geometry;the Pb（2） atom is four-coordinated with four carboxylate oxygen atoms from four different PDB ligands,showing a distorted tetrahedral geometry.It exhibits a three-dimensional supramolecular network structure formed by hydrogen bonds and π-π interactions.

A Novel Two-dimensional Lead(Ⅱ) Coordination Polymer Based on Dinuclear Lead(Ⅱ) Unit Containing(5-Chloro-quinolin-8-yloxy) Acetate

A novel two-dimensional lead（II） coordination polymer 1, [C11H7Cl2NO3Pb]n, has been prepared by solvothermal reaction of new bridging ligand（5-chloro-quinolin-8-yloxy）acetic acid（HL） with PbCl2, and its structure was characterized by IR, elemental analysis, TG-DTA and single-crystal X-ray diffraction analysis. The crystal is of monoclinic system, space group P21/c with a = 16.7603（7）, b = 8.6907（4）, c = 8.4745（3）A, β = 101.1110（11）°, C11H7Cl2NO3 Pb, Mr = 479.27, V = 1211.25（9）A3, Z = 4, Dc = 2.628 g/cm^3, F（000） = 880, μ = 14.367 mm^-1, R = 0.0173 and wR = 0.0508. The asymmetric unit contains one lead（II） cation, one（5-chloro-quinolin-8-yloxy）acetate（L） ligand and a chloride ion. The PbII center is hepta-coordinated in a distorted pentagonal bipyramidal geometry. The coordination sphere of the Pb atom is completed by two oxygen atoms and one nitrogen atom of the same L ligand, two bridging chloride ions and two bridging oxygen atoms of two adjacent L ligands. Two PbII centers are linked by the two L ligands to form a C2-symmetric dimer unit with a planar [Pb2O2] ring. Each dimer unit acts as a secondary building unit（SBU） and links adjacent four dimer units by the chloride atoms and oxygen atoms of carboxylate groups of L, forming a two-dimensional array. Such two-dimensional layers are packed through intermolecular C–H…Cl hydrogen bonds into a three-dimensional supramolecular structure. When the dimer unit is viewed as a 4-connected node, 1 is simplified as a 4-nodal 2-D network with square lattices of the diagonal lengths to be 6.079（1）A. The fluorescence emission peak of complex 1 appears near 407 nm.

Hydrothermal Synthesis,Structure and Photo-luminescence of a 2D Lead（Ⅱ） Coordination Polymer with （4,6^3）Topology Based on Pb and 1,2,3,4-Butanetetracarboxylate Nodes

A lead（II） coordination polymer,{[Pb2（butca）（H2O）2]（H2O）2}n （1）,has been synthe-sized by the hydrothermal reaction of Pb（OH）2 and 1,2,3,4-butanetetracarboxylic acid （H4butca） at 160 °C.Single-crystal X-ray analyses reveal that it crystallizes in monoclinic,space group P21/c with a=7.616（5）,b=7.584（4）,c=12.314（7）,β=105.595（12）o,V=685.0（7）3,Z=4,C8H14O12Pb2,Mr=716.57,Dc=3.474 g/cm3,μ=24.610 mm-1,F（000）=644,the final R=0.0381 and wR=0.1176 for 1465 observed reflections with I 〉 2σ（I）.The complex presents a 2D-layered structure featuring two different types of rings,and has a （4,36）topology based on Pb and butca4-nodes.In solid state,complex 1 shows photoluminescence with the maximum emission intensity at 468 nm under 286 nm excitation.

Electrochemical Determination of Trace Amounts of Lead (Ⅱ) and Cadmium (Ⅱ) at a Calix[6]arene Modified Carbon Paste Electrode

An electrochemical method for the simultaneous determination of lead(II) and Cadmium(II) with a calix[6]arene modified carbon paste electrode (CPE) has been developed. Pb2+ and Cd2+ were accumulated at the surface of the modified electrode via formation of chemical complexes with calix[6]arene, and reduced at 1.40 V. During the following anodic potential sweep, reduced lead and cadmium were oxidized, and two well-defined striping peaks appeared at about ?0.60 V and ?0.84 V. Compared with a bare carbon paste electrode, the calix[6]arene modified CPE greatly improves the sensitivity of determining lead and cadmium. The stripping peak currents change linearly with the concentration of Pb2+ 3.0×10?8–8.0×10?6 mol·L?1 and with that of Cd2+ 6.0×10?8–1.0×10?5 mol ·L?1. The detection limits of Pb2+ and Cd2+ are found to be 8.0×10?9 mol·L?1 and 2.0×10?8 mol·L?1, respectively. The modified carbon paste electrode was applied to determine trace levels of lead and cadmium in water samples. Comparing with that of atomic absorption spectrometry, the results suggests that the calix[6]arene modified CPE has great potential for the practical sample analysis. Key words lead(II) - cadmium(II) - calix[6]arene - differential pulse stripping voltammetry - chemically modified electrode CLC number O 657.15 Foundation item: Supported by the National Natural Science Foundation of China (60171023)Biography: JI Xiao-bo (1980-), male, Master, research direction: electroanalytical chemistry.

Application of 3A Zeolite Prepared from Venezuelan Kaolin for Removal of Pb (II) from Wastewater and Its Determination by Flame Atomic Absorption Spectrometry

This work consists in the use of a 3A zeolite (K-LTA) obtained by a process of exchange of sodium for potassium (4A zeolite), synthesized from Venezuelan kaolin for the removal of Pb (II) ions from aqueous solutions by batch process mode in order to consider its application in treating industrial wastewaters. The 3A zeolite was characterized for X-ray powder diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR) and scanning electron microscopy and energy dispersive X-ray microanalysis (SEM-EDX). The metal concentration in the equilibrium Ce (mg·L-1) after adsorption with 3A zeolite was analyzed using flame atomic absorption spectrometry (FAAS). The influences of the solution pH, contact time, metal initial concentration and adsorbent dosage have been studied. The retention of metal occurring at pH values around 6.5 and the adsorption equilibrium was obtained at 60 min. The equilibrium process was well described by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models. The Langmuir parameters qm (mg·g-1) and b (L·mg-1) (which are related to the sorption capacity and constant of sorption energy) obtained were 14.64 and 5.42 respectively. The Pb (II) experimental uptake was about 14.56 mg·g-1, a little smaller than the theoretical one given by Langmuir isotherm model. The regression parameters and correlation coefficients (R) indicate that the adsorption data for Pb (II) removal fit better the Langmuir isotherm model. Moreover, 0 1/n 1 (1/n is 0.13), indicating that adsorption of metal ions on the zeolite, is a favorable physical process. The application of removing of the metal lead from real samples was examined by industrial wastewater samples. For all samples, the percentage of recovery was found with accuracy of more than 98%. The present work suggests 3A zeolite used as a sorbent material with relatively low cost, obtained from Venezuelan raw material;it is a candidate for removal lead ion and probably other cationic heavy metal species from wastewater.

Data acquisition and control system for lead-bismuth loop KYLIN-Ⅱ-M

Among different heavy liquid metals(HLMs), lead-bismuth eutectic(LBE) is considered at present as a potential candidate for the coolant of new generation fast reactors(critical and subcritical) and for liquid spallation neutron sources and accelerator driven systems(ADS). A high temperature liquid LBE loop, KYLIN-II-M,has been built to study the characteristics of corrosion and fluidity of LBE at the Institute of Nuclear Energy Safety Technology. However, due to the sensors and execution components of the loop work at high temperatures and in severely corrosive environments, the reliability and security of the data acquisition and control system(DACS) of KYLIN-II-M face challenges during the loop operation. In order to meet the urgent needs for KYLIN-II-M's long-term stable operation, a virtualization and redundancy control system has been developed.The onsite operation result shows that the DACS is stable and reliable. In this paper, the experimental results are described in detail.

三甲氧基苯基荧光酮光度法测定生物样品中铅

研究了微乳液介质中,在pH91时,铅与三甲氧基苯基荧光酮(TMPF)显色生成稳定的1∶2配合物,在565nm处摩尔吸光系数为532×104L·mol-1·cm-1,铅含量在0～15μg·mL-1范围内符合比耳定律。巯基葡聚糖凝胶是一种将巯基基团引入葡聚糖骨架上的新型离子吸附剂,其吸附容量大,洗脱容易,机械性能好。采用巯基葡聚糖凝胶分离富集,消除了共存离子的干扰,显著提高了分析方法的选择性。测定了血样、发样和尿样中的痕量铅,结果令人满意。

微乳液增敏邻硝基苯基荧光酮光度法测定食品中痕量铅

本文研究了在微乳液介质中,pH=10.0时,铅与邻硝基苯基荧光酮(o NPF)显色生成稳定的1∶3配合物,在598nm处摩尔吸光系数为8.74×104L·mol-1·cm-1,铅含量在0～1.2μg/mL范围内符合比耳定律。采用巯基葡聚糖凝胶分离富集,消除了共存离子的干扰。用所拟方法测定食品中的微量铅,结果令人满意。

基于十六烷基三甲基溴化铵存在下铅、银离子的高灵敏度电化学测定

报道了在适量十六烷基三甲基溴化铵 (CTMAB)存在下 ,高灵敏度测定水体中铅、银离子的化学修饰碳糊电极。在pH 2 .5 0 .1mol LKNO3溶液中 ,铅、银离子在钠型蒙脱石修饰碳糊电极上通过离子交换而富集 ,同时被还原。在阳极扫描过程中 ,分别在 - 0 .5 2V和 0 .2 3V(vs.SCE)处出现灵敏的溶出峰。详细研究了测定水样中铅、银离子的条件 ,如介质的pH、CTMAB用量、修饰剂用量、富集电位和时间等。该修饰电极连续测定铅、银离子的线性范围为 5 .0× 10 - 9mol L～ 1.0× 10 - 7mol L(Pb2 + )和 8.0× 10 - 9mol L～ 1.0× 10 - 7mol L(Ag+ ) ,富集 4min后检出限分别为 1.0× 10 - 1 0 mol L(Pb2 + )和 3.0× 10 - 1 0 (Ag+ )。

铅离子印迹聚合物选择性吸附特性的研究与应用

利用离子印迹技术以铅离子为模板,甲基丙烯酸为功能单体,偶氮二异丁腈为引发剂,乙二醇二甲基丙烯酸酯为交联剂,采用本体聚合法制备铅离子印迹聚合物。通过红外光谱和紫外光谱对该离子印迹聚合物进行表征,采用静态平衡吸附实验分析铅离子印迹聚合物的吸附性能和吸附选择性。实验结果表明:与非印迹聚合物相比较,Pb(II)印迹聚合物对Pb(II)具有较强的吸附能力和较好的吸附选择性,饱和吸附量为19.44mg/g,pH=6时吸附效果最好,达到吸附平衡的时间是7h;静态分配系数Kd和选择性系数k分别为1381ml/g和20.3。将该离子印迹聚合物应用于环境水样中铅离子测定时的预富集,结果满意。

氨基膦酸树脂对汞、铅混合液的吸附研究

研究氨基膦酸树脂对汞、铅混合溶液的吸附行为 .结果表明 :树脂对混合溶液中的汞、铅都能产生吸附 ;当混合溶液中汞、铅浓度相同时 ,树脂对铅的吸附率要大于树脂对汞的吸附率 ;当混合液中汞、铅浓度不相同时 ,在实验条件下 ,无论是汞的浓度大于铅的浓度 ,还是铅的浓度大于汞的浓度 ,其吸附率都是树脂对铅的吸附率大于树脂对汞的吸附率 ;当树脂的功能基与溶液中汞、铅离子的物质的量相当时 ,树脂能基本完全吸附溶液中的汞、铅离子 .所以 ,氨基膦酸树脂可作为含汞、铅废水的实用吸附剂 .

CuZnMgAl水滑石衍生金属氧化物对废水中Pb(Ⅱ)的吸附

采用共沉淀法合成了不同物质的量之比的CuZnMgAl水滑石(CuZnMgAl-HT),采用X射线衍射仪和热分析仪分析了其晶体结构和热稳定性;将CuZnMgAl-HT的焙烧产物作为吸附剂,测定了其对废水中Pb(Ⅱ)的吸附性能.结果表明,最佳吸附条件为温度30℃,pH 6.0,初始浓度80mg/L,水滑石前体Cu、Zn、Mg、Al的金属物质的量之比为1∶1∶4∶2,吸附时间40min时,相应的吸附率可达95.23%.

高容量螯合树脂的制备及其对Pb^(2+)吸附性能研究

本文以甲基丙烯酸缩水甘油酯(GMA)为单体,氯甲基化的交联聚苯乙烯树脂(CMCPS)为大分子引发剂,CuBr/2,2ˊ-联吡啶(Bpy)为催化剂,采用原子基团转移自由基聚合技术,使甲基丙烯酸缩水甘油酯(GMA)聚合在CMCPS树脂表面,制得了环氧化聚合物,将该聚合物与三聚氰胺反应,制备了高容量三聚氰胺型螯合树脂(Melamine-PGMA-CMCPS),用X射线能谱、元素分析和电镜对其进行了表征,并对其吸附性能进行了研究,并详细研究了吸附树脂的吸附性能、动力学参数。在pH=5.0的缓冲体系中,螯合树脂对Pb2+的吸附能达到最大值,吸附量为612.84mg/g;Pb2+在树脂上的吸附性能用Langmuir方程很好地拟合;动力学研究表明,吸附过程符合准二级动力学方程;洗脱再生实验表明,Melamine-PGMA-CMCPS螯合树脂对Pb2+吸附快、易洗脱、再吸附性能良好。

甲壳素对铅(Ⅱ)的吸附研究

进行了铅离子在甲壳素上的吸附行为实验,结果表明在pH=4.46时吸附最佳。测得静态饱和吸附容量为478mg.g-1(树脂);用0.5mol.L-1HCl可洗脱,洗脱率达98.8%;测得表观速率常数k298=8.53×10-5s-1;表观活化能Ea=16.54kJ.mol-1;等温吸附服从Freundlich经验式;吸附热力学参数△H=8.70kJ.mol-1,△S=41.7J.mol-1.K-1,△G=-3.71kJ.mol-1。