乳状液膜分离Zn^2＋的界面传质阻力及传质模型

用Ｌｗｅｉｓ恒界面传质池对乳状液膜分离Ｚｎ＾２＋的传质阻力进行实验研究，结果表明由于表面活性剂单分子层的形成，使界面传质阻力占整个传质阻力的８５％。在此基础上所建立的既考虑界面传质阻力又考虑膜破碎的液膜传质模型能使用理论计算值与实验测定值符合较好。     

液膜法提取分离对氨基苯甲酸的研究

由磷酸三丁酯(TBP)、表面活性剂和煤油为油相,氢氧化钠溶液为内水相,含对氨基苯甲酸(PABA)的水溶液为料液(外水相),组成了W/O/W型乳状液膜体系,用乳状液膜法对料液中的PABA进行了分离富集研究。探讨了PA-BA在水中的形态分布及其液膜分离的传质机理,考察了表面活性剂种类、TBP质量分数浓度、外水相pH值和内水相氢氧化钠浓度等因素,对PABA传质分离的影响。结果表明,采用适宜的乳状液膜体系,在最佳的操作条件下,对含PABA浓度为500 mol/L的料液进行分离富集时,仅经一级液膜分离过程,PABA的分离提取率可达99%。     

液膜法脱除废水中的氰化物

本文用聚胺E644作乳化剂,研究了用内相包裹NaOH 水溶液的W/O 型乳状液脱除废水中氰化物的方法。讨论了影响液膜稳定性、液膜传质速率等的因素.表面活性剂浓度、油内比、乳水比、温度及搅拌速度对液膜的稳定性及液膜传质速率均有不同程度的影响。确认本系统中氰化物的迁移属Ⅰ型促进传递机理。本文还导出了同时考虑外相边界层及膜相传质阻力的固定液滴——渐进前沿模型。采用摄动法求得了该模型的零级近似解。模型计算值与实验值能很好地符合。     

乳状液膜法提取分离水中苯胺

采用非流动载体乳状液膜体系对水中苯胺的提取进行了研究.考察了影响苯胺传质的几种因素：内水相盐酸浓度、外水相pH值、表面活性剂种类和浓度、乳水比等.结果表明,在适宜的操作条件下,当水中苯胺浓度为500 mg·L^-1时,经过一级液膜处理,水中苯胺的含量可降到1.5 mg·L^-1.另外初步探讨了表面活性剂的结构和性质对膜相黏度、界面黏度、稳定性和苯胺传质速率的影响.     

乳状液膜提取青霉素及其溶胀的研究

采用W／O型乳状液膜提取模拟发酵液中的青霉素,考察膜相添加剂、表面活性剂、载体、解析剂Na2CO3浓度、搅拌速度对青霉素传质和液膜溶胀的影响。以span80为表面活性剂、三辛胺为流动载体、液体石蜡为膜相添加剂、煤油为膜溶剂组成的乳状液膜体系。结果表明：青霉素提取率随表面活性剂和载体浓度的增加而明显增加。但表面活性剂浓度增加使液膜易产生再乳化,而再乳化和搅拌是夹带溶胀产生的主要原因;水的渗透(渗透溶胀)随载体和内相NaCO3浓度升高而增加。液膜溶胀是影响液膜技术工业化应用的关键因素之一。适宜的液膜配方和操作条件,有利于控制液膜溶胀,增加青霉素的提取率。在本研究中,青霉素的提取率最高可达91．5％,液膜溶胀率为16％。     

用乳状液型液膜提取铕的传质机理研究

本文研究了用乳状液型液膜提取稀土元素铕的工艺条件,考查了不同因素对铕的传质速率的影响.实验结果表明,以二(2-乙基己基)磷酸为载体,硝酸为解络剂的乳状液型液膜对铕的迁移效果很好.本文重点探讨了该液膜体系的传质机理,推导出本体系的传质通量式,并用实验数据进行了验证,取得了较好的一致性.     

无外界氧补偿条件下乳状液中多不饱和脂肪酸氧化模型

建立了在无外界氧补偿条件下乳状液中多不饱和脂肪酸(PUFA)氧化的数学模型。该模型综合考虑了乳化剂形成的液膜边界层阻力、PUFA自催化氧化反应以及油水相比表面积等因素的影响。实验验证了该模型能较好地拟合无外界氧补偿条件下乳状液中氧的扩散和亚油酸的氧化过程,并模拟计算了乳化剂膜传质系数和油水相比表面积等因素对扩散-氧化的影响程度。结果表明,乳化剂膜传质系数和油水相比表面积是影响乳状液中PUFA的氧化的主要因素。     

乳状液膜法处理三氯乙醛废水的研究

本工作是用乳状液膜法处理三氯乙醛废水的初步实验.实验系将氢氧化钠水溶液包以煤油作为液膜,处理含有50—200ppm的三氯乙醛水溶液.实验考察了影响三氯乙醛渗透的一些因素,在适当的条件下可以脱除95%以上的三氯乙醛.并计算了该液膜体系的总包传质系数,结果表明它趋向于一个恒定值.     

乳状液膜扩散－反应双控制过程传递机理数学模型研究

本文建立了乳状液膜扩散－反应双控制过程传递机理的数学模型,该模型综合考虑了膜外相边界层,金属离子与载体的界面化学反应以及膜相阻力等因素对传质的影响。实验验证了该模型具有较好的适应性,并模拟计算了各因素对传质的影响程度     

乳状液膜扩散—反应双控制过程传递机理数学模型研究

本文建立了乳状液膜扩散－反应双控制过程传递机理的数学模型，该模型综合考虑了膜外相边界层，金属离子与载体的界面化学反应以及膜相阻力等因素对传质的影响。实验验证了该模型具有较好的适应性，并模拟计算了各因素对传质的影响程度。     

Analytical study of type-1 facilitated transport through liquid surfactant membrane

In the present study, a mass transfer model for Type-1 facilitated transport in liquid surfactant membrane is developed by taking into consideration a size distribution of emulsion drops, and analytical solution of the model equations has been presented. The model takes into account the continuous phase and outer liquid membrane phase resistances along with diffusion through composite emulsion drop. Effort has been made to highlight the effect of the various system parameters on the extraction rate including computation of reaction front position. The results of this work are found to be in good agreement with the published experimental results on batch extraction of phenol using NaOH as internal reagent. The model would thus provide an insight of the separation mechanism involved in the mass transfer processes in this type of system.     

Mathematical modeling of penicillin G Extraction by a bifunctional surfactant in a continuous extraction column

A bifunctional surfactant was used as a carrier of penicillin G for its continuous extraction by an emulsion liquid membrane without an extradant in a countercurrent extraction column of Oldshue-Rushton type. A permeation model was presented to describe transport mechanism of penicillin G in the continuous extraction system, including an axial dispersion model for the continuous phase and a mass transfer model for the dispersed emulsion phase. The mass transfer model describes the external mass transfer around the emulsion drop, the reaction at the external interface, the diffusion as well as the reaction equilibrium within the w/o emulsion drop, and the pH change of internal aqueous phase. Here, we considered three experimental variables: penicillin G concentration, pH of continuous phase and surfactant concentration. The calculated results from the permeation model fitted the experimental data well. This paper is dedicated to Dr. Youn Yong Lee on the occasion of his retirement from Korea Institute of Science and Technology.     

A mass transfer model for the extraction of weak acids/based in emulsion liquid-membrane systems

A mathematical model for analysing the extraction of weak acids and weak bases from aqueous solution by liquid surfactant membrane has been presented. The model assumes that the reactions are reversible and the reaction equilibrium to exist in both the internal phase and the external continuous phase. The scheme for mass transfer analysis is based on an immobilized emulsion globule drop model and the classical film theory, i.e. the overall mass transfer resistance includes that due to the external turbulent boundary layer, the interfacial surfactant layer and the diffusion layer within the emulsion globule. The leakage effect of internal phase due to membrane rupture is also discussed in the mathematical treatment. The proposed model predicts satisfactorily the experimental results of the extraction of weak acids as well as weak bases in a batch separation system as presented in the literature.     

Polydispersity effect in facilitated transport through liquid surfactant membranes

An advancing reaction-front model has been proposed in the present study of facilitated transport through liquid surfactant membranes by taking into consideration a size distribution of emulsion drops. The model takes into account the continuous and outer liquid membrane phase resistances along with diffusion through composite emulsion drops. The effect of various dispersion phenomena on the mass transfer rate of solute has been discussed for two different operating conditions corresponding to different drop size distributions but having the same Sauter mean diameter. Membrane leakage is assumed to be negligible.     

THE STUDY ON THE MASS TRANSFER MECHANISM OF EUROPIUM ION THROUGH LIQUID SURFACTANT MEMBRANES

The transfer of trivalent europium ion in a liquid surfactant membrane system is investigated in order toclarify the characteristics of liquid membrane separation process and the availability of this technique forrecovering trivalent lanthanides and actinides.A layered structure model for the emulsion globule is sug-gested.The equations describing the relationship among the effective membrane thickness,the time andother factors are derived and verified experimentally.Results show that under certain conditions the decreas-ing concentration of europium ion in the external phase is proportional to the square root of the time,the acidity of the internal phase and the carrier concentration in the membrane phase.The membrane phase consists of kerosene(solvent),Span-80(surfactant)and di-(2-ethylhexyl) phosphoricacid(HDEHP,carrier).The internal phase is dilute nitric acid and the external phase is aqueous solu-tion containing Eu(NO_3)_3.The mass transfer rate of europium in this system is high and the recovery ofeuropium may be more than 99%.     

Response Surface Optimization of Dysprosium Extraction Using an Emulsion Liquid Membrane Integrated with Multi‐Walled Carbon Nanotubes

A new emulsion liquid membrane was prepared for dysprosium (Dy) extraction from aqueous solution using multi‐walled carbon nanotubes (MWCNTs). The influence of MWCNT concentration, carrier and surfactant concentration, stirring speed, feed‐phase pH, and internal phase concentration and their interactive effects were studied. A regression model for Dy extraction was developed and the parameters were optimized by response surface methodology. The extent of extraction increases with higher MWCNT concentration up to a certain level. The Dy extraction through the liquid membrane containing MWCNT improves with time. Moreover, the overall mass transfer coefficient was enhanced in the presence of MWCNT due to the formation of a more stable emulsion and liquid membrane.     

DEVELOPMENT AND DESIGN OF A LIQUID MEMBRANE ENZYME REACTOR FOR THE DETOXIFICATION OF BLOOD

Liver failure causes the enrichment of different lipophilic metabolites: phenol derivatives, mercaptans and short-chain fatty acids in blood. The removal of these toxines from blood is necessary to avoid death and to support the liver's self-regeneration. The liquid surfactant membrane technique with consecutive chemical reaction is used for this purpose.

Liquid membranes were developed for the extraction of fatty acids. Enhancement of mass transfer is achieved by an instantaneous chemical reaction inside the emulsion globules, selectivity is obtained by using a suitable carrier. Essential fatty acids are not affected. Phenolic compounds are removed by extraction and consecutive enzymatic reaction inside the liquid membrane globules. This way of detoxification is identical with elimination in the living organism. Furthermore, a new model is being developed to describe the results of phenol extraction. This model makes possible the simulation of the detoxification process in the human organism. A flow sheet is proposed showing how to apply the liquid surfactant membrane technique to artificial liver support and the detoxification rate is calculated. Artificial liver Liquid membrane Blood detoxification