中空纤维封闭液膜技术的传质强化研究

以３０％ＴＢＰ（灶油）为萃取剂，ＮａＯＨ水溶液为反萃剂，对聚砜中空纤维封闭液膜萃取苯酚的传质性能进行了实验研究，并在膜器的壳程鼓入空气以期强化过程传质性能，研究结果表明，在中空封闭液膜萃取过程中总传质系数与料液相流速的１／３次方成正比，因为反应速度很快反萃相的传质阻力可以忽略，在鼓入空气的情况下，总传质系数较无气泡鼓入时明显增大，总传质系数仍与料液相流速的１／３次方成正比，而与反萃相的流速基本无关     

均质硅橡胶膜用于含酚水溶液膜萃取传质过程

研究了一种将均质硅橡胶膜与碱性萃取液相结合的新型膜萃取技术,用以处理含酚水溶液的传质机理与过程,并考察了该体系中两相流动状态、萃取液pH、料液浓度、两相压力和温度等因素对苯酚膜萃取传质速率的影响.基于液-膜-液串联传质阻力模型,通过实验测定苯酚的总传质系数Kov.研究表明:对于氢氧化钠-苯酚-水实验体系,传质由膜阻控制,Kov为3.72×10-7m/s;化学反应对苯酚传质速率的增强作用不显著;苯酚溶液浓度＞8000mg/L,Kov与其初始浓度无关;致密膜体系中两相压差的存在不利于传质的进行;Kov与运行温度呈直线关系.     

微乳液-中空纤维膜萃取钕的工艺研究

提出了一种新的膜分离过程即非离子W/O型微乳液-中空纤维膜萃取,所用非离子型微乳液体系为(OP-7 OP-4)/苯甲醇/D2EHPA/煤油/盐酸.在不同微乳液流速、料液流速、微乳液内相盐酸浓度、料液浓度、以及不同中空纤维膜数等条件下进行了微乳液-中空纤维膜逆流萃取Nd3 的研究.结果表明,微乳液和料液流速越小,萃取率越高,内相富集倍数越大.微乳液内相盐酸浓度越大,萃取率越高,但富集倍数反而减小.料液初始浓度越小,萃取率和富集倍数越大.当微乳液流速为6 mL/min、料液与微乳液流速比为3∶1、微乳液内相盐酸浓度为4 mol/L、料液浓度为200 mg/L时,经过微乳液在三个中空纤维膜萃取器中的串联萃取,Nd3 的萃取率达96.3%,内相Nd3 浓度为4238 mg/L,是萃余料液浓度的572.7倍,内相富集倍数为21.2.膜萃取过程与膜溶剂萃取相比对Nd3 有更高的萃取效率.     

液膜接触法处理含铜废水的实验研究

探讨以P204为流动载体的液体表面活性剂膜从酸性水溶液中分离二价铜离子的过程，并对影响二价铜离子透过液膜的重要变量进行分析，这些变量主要是外部水相中的起始铜浓度、外相溶液中的起始pH值、液膜流动载体浓度、乳水比、内相峻浓度等．实验结果表明：较佳膜相组成的液膜能把废水溶液中铜离子浓度从100mg/L降到0．9mg/L;铜萃取率大于99％．     

中空纤维封闭液膜用于乳酸分离

利用中空纤维封闭液膜技术对乳酸的分离进行了研究，采用三烷基胺（７３０１）＋正辛醇＋煤油混合溶剂为萃取剂，以水作为反萃剂，在聚砜中空纤维膜器中进行实验。研究结果表明，在中空纤维封闭液膜技术分离乳酸中，总传质阻力与料液相流速和反萃相流速的１／３次方均呈反比关系。实验研究了鼓泡技术对强化质的影响，在中空纤维膜器壳程中鼓入空气有利于提高传质系数。实验中还讨论了反萃液温度对过程的影响，传质阻力随着操作温度的     

中空纤维支撑液膜去除水中氨氮的传质行为研究

以聚丙烯(PP)中空纤维膜为支撑体,二(2-乙基己基)磷酸(简称D2EHPA)为载体,煤油为膜溶剂,探讨D2EHPA-煤油-H2SO4中空纤维支撑液膜(SLM)体系对水中氨氮的传质行为.以去除率为指标,考察了料液初始氨氮浓度及pH值、载体浓度、反萃剂浓度对传质效果的影响;并通过对比实验分析了导致传质速率降低的主要原因.结果表明:在反萃剂H2SO4浓度为2 mol/L,料液相pH值在8～13范围内,提高料液pH值、增大膜相中载体浓度,均能提高氨氮的去除率.D2EHPA-煤油-H2SO4体系对氨氮的传质能力随氨氮浓度降低而下降.料液中氨氮浓度下降和pH值降低是导致氨氮传质速率降低的主要原因,调节料液pH值可调控和提高氨氮的去除与传质效果.     

气-液膜接触器结构优化及其传质性能研究

以海水作为吸收剂,采用模拟烟气,对气-液膜接触器进行传质性能评价试验,考察其工艺结构参数、气液介质流动速率及方式、气液压差、烟气SO2浓度等因素对传质系数、脱硫率及膜效用的影响.试验表明,在气相压力较低情况下,气液流速、气液压差对总气相传质系数影响明显,而烟气SO2浓度的影响可忽略不计.适当提高膜接触器的填充密度,增加膜吸收级数,采用错流模式的气液流动方式,均可改善烟气流场分布,增大有效传质面积,提高膜效用.与传统吸收塔相比,新型膜气体吸收装置的气液两相独立控制,可灵活应对烟气浓度变化对脱硫稳定性的影响,同时具有低气阻、耐污染、规模可线性放大等优点,工业化应用前景广阔.     

手性配体交换乳状液膜选择性萃取扁桃酸对映体

基于手性配体交换反应,研究了在含有N-n-十二烷基-L-羟基脯氨酸和铜离子的配合物为手性配体的乳状液膜体系中选择性萃取扁桃酸对映体.考察了扁桃酸外消旋体浓度,手性萃取方向,有机溶剂和表面活性剂配比,从外水相到内水相pH值的梯度变化以及外水相的pH值变化对选择性萃取性能的影响,从而确定了合适的选择性萃取条件.     

混合气中C6H6的膜气体吸收分离过程

以疏水性聚丙烯中空纤维膜为气液接触膜,n-甲酰吗啉(n-Formyl morpholine,NFM)水溶液为吸收剂,研究了膜气体吸收技术分离混合气中苯的传质过程,考察了各操作参数对传质过程的影响,建立传质阻力模型,对模型预测值与实验值进行了对比.结果表明:提高气液相流量及浓度、吸收剂浓度,降低吸收液负载有利于提高传质通量.传质过程受液膜控制;在实验条件下,模型预测值与实验值符合较好,最大误差为20.2%,平均误差为9.2%.     

乳状液膜提取稀土的传质模型研究（Ⅲ）

建立的乳状液膜体系中，稀土离子由内水相向外水相迁移的传质模型，探讨了该液膜体系的传质机理．实验结果表明，本文模型准确地描述了液膜体系的传质行为，扩散组分在内水相边界层和膜相的扩散阻力是主要的传质阻力     

膜萃取去除水中氯仿的研究

采用煤油－氯仿－水为实验体系,在两种不同型号的的聚丙烯中空纤维膜器中进行了连续逆流膜萃取过程的研究．计算了基于水相的总传质系数Ｋｗ,分析了实测值与计算值之间的偏差．实验结果表明,传质由水相边界层控制,壳程的非理想流动是造成偏差的主要原因．通过计算传质单元高度ｈＨＴＵ及测定萃取前后氯仿水溶液的ＣＯＤ值,证明了中空纤维膜萃取去除水中氯仿的高效性     

Permeation liquid membrane metal transport: studies of complex stoichiometries and reactions in Cu(II) extraction with the mixture 22DD-laurate in toluene/phenylhexane

The role of lauric acid (LAH) in the transport of copper(II) through a permeation liquid membrane (PLM) comprising 1,10-didecyldiaza-18-crown-6 (22DD) and lauric acid (ratio 1:1) in 1:1 v/v toluene/phenylhexane has been investigated by determining the stoichiometry of metal extraction and of the metal complex formed in the organic phase by performing 1H NMR and liquid/liquid and liquid/membrane extraction measurements. In the absence of copper(II), the 1H NMR data suggest that there is a strong interaction between the proton of LAH and the nitrogen of the 22DD macrocycle but no interaction between the aliphatic long chains of LAH and 22DD. Thus, in the organic solution, the two compounds are associated as (22DD-H)(+)-LA-, the laurate being away from (22DD-H)+. The signal intensity of the acidic proton was found to decrease when the metal Pb(II) was incorporated by the carrier after its extraction from the aqueous phase. Additionally, liquid/liquid as well as liquid/membrane extraction results reveal that Cu(II) extraction proceeds via the loss of two protons from the organic phase. The Cu(II) is found to be located in the 22DD cavity and the stoichiometry of the complex in the organic phase is (22DD-Cu)(2+)-2LA-. Metal extraction is governed by 22DD and laurate acts only as counteranion. An unexpected feature was observed in the liquid/liquid extraction which was that, at low 22DD and LAH concentrations, the slope for log(Kp) = f(pH) was 2 whereas it was much lower at high carrier concentration. This unexpected result seems to stem from impurities present in 22DD: only 0.1 mol% of impurity can indeed influence the exchange ratio of Cu(II) and H+. This type of anomaly, however, is not found in the normal procedure of liquid/membrane extraction possibly due to the lower carrier/metal molar ratio which is used in the classical PLM conditions.     

钒基普鲁士蓝类似物VHCF用于水系铜电池正极

针对开发高性能水系铜电池电极材料的迫切需求,通过简易的共沉淀法制备钒基普鲁士蓝类似物铁氰化钒(VHCF)用作水系铜电池正极,考察反应温度及转速对VHCF样品表面形貌及微观结构的影响,探究不同VHCF样品在电化学性能上的差异,并分析VHCF样品的铜离子储存机理。研究结果表明：通过适当提升反应温度及搅拌器的转速,可以制备出[Fe(CN)₆]^4-含量多,粒径小且结构稳定的立方相VHCF;丰富的[Fe(CN)₆]^4-可以为Cu²⁺离子提供更多的化学活位点,较小的粒径有利于提高Cu²⁺离子的扩散速率,与普鲁士蓝骨架结合更稳定的结晶水则能改善电池循环稳定性;电化学反应过程中,Cu²⁺离子会取代VHCF骨架中的V⁵⁺离子形成不可逆新相。VHCF正极在0.1 A/g电流密度下的首次放电比容量高达146.5 m A·h/g,循环500次后,保留了56.1 m A·h/g的可逆容量;在1.0 A/g的大电流密度下的放电比容量仍有60...     

Preconcentration and separation of nickel, copper and cobalt using solid phase extraction and their determination in some real samples

A solid phase extraction method has been developed to separate and concentrate trace amounts of nickel, cobalt and copper ions from aqueous samples for the measurement by flame atomic absorption spectrometry. By the passage of aqueous samples through activated carbon modified by dithioxamide (rubeanic acid) (DTO), Ni2+, Cu2+ and Co2+ ions adsorb quantitatively. The recoveries of analytes at pH 5.5 with 500 mg solid phase were greater than 95% without interference from alkaline, earth alkaline and some metal ions. The enrichment factor was 330. The detection limits by three sigma were 0.50 microg L(-1) for copper, 0.75 microg L(-1) for nickel and 0.80 microg L(-1) for cobalt. The loading capacity was 0.56 mg g(-1) for Ni2+, 0.50 mg g(-1) for Cu2+ and 0.47 mg g(-1) for Co2+. The presented procedure was applied to the determination of analytes in tap, river and sea waters, vegetable, soil and blood samples with successfully results (recoveries greater than 95%, R.S.D. lower than 2% for n=3).     

中空纤维膜接触器分离CO2/N2混合气体的研究

以氢氧化钠(NaOH)、单乙醇胺(MEA)、二乙醇胺(DEA)为吸收剂,采用疏水性聚丙烯中空纤维微孔膜接触器技术进行了从CO2/N2混合气中分离CO2的研究.从机理上简要探讨了影响CO2吸收传质的因素.结果表明3种吸收剂分离CO2的效率依次为MEA＞NaOH＞DEA,CO2的分离效率随吸收剂浓度和流速的提高而增大,随混合气流速及其中CO2浓度的增大而减小;在壳流程与腔流程的对比中腔流程对CO2的吸收效率要明显好于壳流程.     

膜接触器分离混合气中二氧化碳

以N-甲基二乙醇胺（MDEA）水溶液为吸收剂,采用疏水性聚丙烯中空纤维膜组件（HFPPM）作为膜接触器,研究了膜接触器分离CO2/N2混合气传质性能,主要考察了吸收剂浓度,液速,吸收温度,原料气浓度和气速等因素对CO2吸收性能的影响,比较了同一膜组件不同流程和不同膜组件及膜形态对分离效果的影响,并对膜组件运行的稳定性进行了初步考察,实验结果表明,采用MDEA溶液和HFPPM膜接触器分离CO2/N2混合气具有较快的传质速率和较高的分离效率．     

Influence of surfactant entrapment to dried alginate beads on sorption and removal of Cu2+ ions

The removal of heavy metals has been investigated widely in recent years due to their potential health risk to human beings. In this study, the removals of copper from aqueous phase by alginate and SDBS entrapped alginate was investigated. First, a series of equilibrium sorption experiments were conducted at different initial pH values. Both equilibrium copper concentration and final pH values were observed. Then, a series of kinetic experiments were conducted and a second order rate relationship was fit to the experimental data. Equilibrium sorption experiments showed that the sorption of Cu+2 ions by 2% of SDBS entrapped alginate beads were greater than the plain and 0.5% of SDBS entrapped alginate beads. More H+ ion exchange occurred with the 2% of SDBS entrapped alginate beads, which was attributed to the increased number of the exchange sites on the alginate due to the sorption of surfactant to the beads. Kinetic sorption experiments showed that the equilibrium was reached faster for 2% of SDBS entrapped alginate beads. Results were successfully represented using second order kinetic model. Both equilibrium and kinetic experiments showed that the sorption of Cu+2 ions increased as the pH of the aqueous solution increased.     

异相共混螯合滤膜的制备及其性能研究

通过探讨共混比例、螯合树脂粒径、PSF（聚砜）浓度及制膜液温度对膜性能的影响,用相转换法制备出对Cu^2＋具有大螯合容量的D418树脂／聚砜异相共混螯合滤膜。研究了膜对Cu^2 的吸附及盐溶液pH值和盐浓度对螯合容量的影响。对膜进行动态螯合吸附测试表明该膜对Cu^2 可实现萃取与反萃取同级进行。     

用双环己酮乙二酰二腙分光光度法测定浸锌液中的Cu2+

基于铜与双环己酮乙二酰二腙(BCO)的显色反应,以柠檬酸铵为掩蔽剂,氯化铵-氨水为缓冲溶液,调节溶液pH值为8.6～10.0,使铜与BCO的蓝色生成物稳定保持在水相中,直接进行光度分析,据此建立了测定浸锌液中铜的分光光度分析法.测试结果显示:显色溶液在600nm处有最大吸收峰,Cu2+测量的范围是0.02～4.00mg...