Active transport of alkali metal ion through a membrane composed of gluconolactone-containing polymer

Summary The membrane composed of gluconolactone-containing polymer was prepared by the following three steps, (1) the copolymerization between acrylonitrile and a styrene derivative carrying a protected glucose substituent, (2) casting a membrane from the DMF solution of the copolymer, and (3) a sequence of reactions for the membrane. It exhibited active transport of Na⁺ ion against the concentration gradient.     

液氯泵在液氯输送包装中的应用

介绍液氯泵在液氯输送包装中的应用,总结比较不同液氯输送包装工艺特点和液氯泵特性。     

氯离子选择性电极测定钻井废水中的氯离子含量

利用氯离子选择性电极测定钻井废水中的氯离含量，分别用两种方法对钻井废水进行了预处理．氯离子在0～250mg／L的范围内线性关系良好，相关系数为0．9968，并且重现性和选择性良好，精密度与准确度较理想。     

High performance electrode for electrochemical oxygen generator cell based on solid electrolyte ion transport membrane

A double-layer composite electrode based on Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3−δ + Sm_0.2Ce_0.8O_1.9 (BSCF + SDC) and BSCF + SDC + Ag was investigated to be a promising cathode and also anode for the electrochemical oxygen generator based on samaria doped ceria electrolyte. The Ag particles in the second layer were not only the current collector but also the improver for the oxygen adsorption at the electrode. a.c. impedance results indicated that the electrode polarization resistance, as low as 0.0058 Ω cm² was reached at 800 °C under air. In oxygen generator cell performance test, the electrode resistance dropped to half of the value at zero current density under an applied current density of 2.34 A cm⁻² at 700 °C, and on the same conditions the oxygen generator cell was continual working for more than 900 min with a Faradic efficiency of ∼100%.     

木质素中氯离子的测定方法探讨

木质素含有过高浓度的氯离子会对牲畜、土壤、植物生长造成严重而持久的危害,并危害人体健康。采用摩尔法、佛尔哈德返滴定法和电位滴定法测定木质素中的氯离子,并分别利用F检验和t检验进行分析。结果表明,3种测定方法的精密度无显著性差异,加标回收率在98%～101%,准确度较好;摩尔法的平均值与佛尔哈德返滴定法或电位滴定法的平均值存在显著性差异,佛尔哈德返滴定法与电位滴定法的平均值之间无显著性差异;但是相比较而言,电位滴定法的准确度和精密度最好,佛尔哈德返滴定法次之。建议采用电位滴定法对木质素中的氯离子进行检测。     

炉水氯离子控制的探讨

主要介绍了氯离子监督在热力系统的重要性,并对氯离子检测方法进行了比较,并重点介绍本厂氯离子监督的方法,并介绍了炉水氯离子超标的原因和降低氯离子的方法。     

Active transport membrane for anions. III. Effect of crown ether and tautomeric functional groups

Membranes derived from copolymers having N-hydroxyalkyl groups were prepared, and the active transport for anions through the membranes was investigated in the presence of a crown ether which suppresses the diffusion of counter ions. The maximum of the concentrated anions in one side cell was maintained for a long time by the addition of a crown ether in the cell, and a concentration of anions up to 50% was attained. Various N-hydroxyalkyl groups of different lengths were incorporated in copolymers with styrene, and the transport for anions was investigated in order to establish the carrier mechanism of the tautomeric functional groups. Longer-length alkyl moieties bearing N-hydroxyalkyl groups led to a decrease in the active transport for anions, which supports a carrier mechanism for the membranes.     

Determination of transport properties and limiting current densities of ion exchange membrane stacks

For the economy of electrodialysis desalination plants it is important to know the permselectivities and permeabilities of the ion exchange membranes used. In particular, when dealing with high salt contents the permeabilities should be small. The relationship between ion flux density and current density was measured with a membrane stack. The experimental data are reasonably accurate, however only as obtained for a combination of an anion exchange membrane with a cation exchange membrane.The permselectivities are compared with data of the apparent permselectivities as obtained from measurements of the membrane potential. In addition, permeabilities were calculated from data of tracer experiments as well as from electrochemical membrane data.Economic assessments also require a knowledge of the limiting current density of the combination of a cation- and an anion exchange membrane, for at higher current densities there will be a loss of both energy and product water.The limiting current density was determined for various membrane combinations as a function of liquid flow.     

液氯输送技术探讨

介绍了气化器、液氯屏蔽泵、液氯液下泵、液氯磁力泵的工作原理和工艺流程、工艺特点，并指出了它们的优点和缺点。     

A study on the transport behavior of cations in ion exchange membrane electrodialysis

The permselectivities of cations in ion exchange membrane electrodialysis for NaCl-MgCl₂ and NaCl-CaCl₂ systems are investigated. The experimental results show that the permselective coefficients T^Mg_Na and T^Ca_Na decrease as the current density increases, but increase as the bulk velocity and the total equivalent concentration of diluent increases at constant temperature. It also indicates that the permselectivity is independent of the composition of diluent at constant current density, temperature, flow rate and total equivalent concentration of diluent. The correlation of experimental results shows that the empirical relation between permselective coefficient and Stanton number St can be expressed by the following equations: T^Mg_Na = 1.527 St^-0.51 as 0.23 × 10^-3 < St < 0.9 × 10^-3 and T^Mg_Na = 1.05 as St > 0.9 × 10^-3 for NaCl-MgCl₂, system; and T^Ca_Na= 1.412 St^-0.403 as 0.4 × 10^-3 < St < 2 × l0^-3 and T^Mg_Na = 1.185 as St > 2 × 10^-3 for NaCl-CaC1₂ system. The result also indicates that the permselective coefficient T^B_A decreases and approaches to the value of the ratio of the ionic mobility U_B/U_A as Stanton number increases.     

新型氯离子吸附剂的制备及性能研究

利用低饱和共沉淀法、焙烧还原法,制备活性炭改性焙烧镁铝水滑石。将其作为吸附剂,处理质量浓度为100mg/L的含氯模拟废水。实验结果与传统水滑石比较,氯离子吸附率提高6.22%,成本降低35.42%。在性价比方面明显优于传统水滑石,具有明显的环境与经济效益。     

一种有机膦酸水处理剂中氯离子含量的检测方法

现有氯离子检测方法都存在亚磷酸与硝酸银发生反应对点位滴定的干扰现象,影响终点的判断,笔者创新性的提出了一种有机膦酸类水处理剂中氯离子含量的检测方法,使用双氧水氧化水处理剂中残余的亚磷酸,进行双盐桥电位滴定来测定氯离子,电位突跃明显,终点易于辨认,并考察了方法的准确度和精密度,结果理想。     

A mathematical model of multiple ion transport across an ion-selective membrane under current load conditions

A macrohomogeneous mathematical model of the simultaneous transport of multiple ions across an ion exchange membrane based on the Nernst–Planck equation was developed. Schlögl's equation of motion was used to evaluate the convective term of the mass-transfer inside the membrane. The model accounts for the external diffusion of the ions through the Nernst diffusion layer to the phase boundary on both sides of the membrane. Donnan equilibrium is used to describe the potential and the concentration discontinuity on the membrane-solution interface. The results document the importance of the external diffusion layers for ion transport across the membrane.     

Rapid microanalytical chlorine determination in polymers by ion selective electrode

A rapid microanalytical method has been developed for the determination of very small amounts of chlorine in polymers. The gist of the method comprises quantitative dechlorination by sodium biphenyl or dehydrochlorination bytert-BuOK, aqueous extraction of the Cl^? formed, followed by [Cl^?] quantitation by chloride ion selective electrode (CSE). The method has been tested and is now used routinely for chlorine end group quantitation of telechelic polyisobutylene (PIB), poly(2,4,6-trimethylstyrene) (PTMSt), and poly(p-chlorostyrene) (PpClSt).     

电石泥中氯离子含量的测定

采用汞量法和分光光度法对电石泥中氯离子进行测定。结果表明2种分析方法测试数据准确度都较高,都可以作为氯离子含量的分析方法,但分光光度法测定方法简单,对环境无污染,在环保方面优于汞量法。     

离子色谱法测定化肥催化剂中的氯含量

采用离子色谱法测定了化肥催化剂中氯含量。建立了化肥催化剂中Cl含量的检测方法,选择了合适的分析条件。考察了样品粒度、浸取次数以及浸取时间对化肥催化剂中氯含量的影响,研究结果显示样品粒度低于0.075 mm、一次浸取和30 min浸取时间能够将化肥催化剂中氯有效溶出。同时建立了氯组分的标准工作曲线,线性相关系数大于0.999。在7种化肥催化剂中Cl的回收率为94%~114%,相对标准偏差不大于10.7%,完全满足工业分析测定需要。该方法具有灵敏、准确和简便等优点,对于测定化肥催化剂中氯含量显示出明显的优势。     

On rigorous definition of ion transport process and accurate determination of membrane potential at steady state

Ion transport plays an important role in many fields, such as signal generation and transmission in neural systems, function of ion channel on bio-membranes, and water demineralization with nanofiltration and reverse osmosis. The electrical potential concurred with ion transport on a membrane not only reflects the properties of ions (e.g., charge, concentration, and mobility) but also regulates the transport rates of the ions. However, accurate determination of membrane potential remains a severe challenge because of the difficulties in specifying the appropriate boundary conditions for the governing Nernst–Planck–Poisson equations. An innovative boundary condition updating scheme was developed in this study to ensure that the boundary conditions are consistently imposed for both Nernst–Planck equation and Poisson's equation at any time. With this scheme, the general ion transport process can be rigorously defined and formulated for the accurate determination of membrane potential.