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1.
乳状液膜提取稀土的传质模型研究(Ⅱ)   总被引:1,自引:1,他引:0  
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,扩散经发在内水相边界层和膜相的扩散阻力 主要的传质阻力。  相似文献   

2.
均质硅橡胶膜用于含酚水溶液膜萃取传质过程   总被引:1,自引:0,他引:1  
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.  相似文献   

3.
乳状液膜状分离氨基酸的动力学   总被引:2,自引:0,他引:2  
探讨了含载体P204(磷酸二异辛酯)的液膜体系用于苯丙氨酸促进运输的动力学行为,采用液滴法装置,控制实验条件,测定了内相氢离子浓度随时间的变化,适用于有机相界面的化学反应对溶质传递的影响,并将计算的结果同实验相比较,建立了水相-有机相界面化学反应对溶质传质具有决定作用时的传质模型。  相似文献   

4.
大试剂比条件下液膜传质机理   总被引:2,自引:0,他引:2  
提出了确定液膜过程传质机理的新方法,其要点为:在膜相中增加载体浓度,就会提高溶质在膜相的分配比,一般也会提高液膜中传质速度.比较分配比提高的倍数和传质速度提高的倍数,可判断该过程的速控步骤:如这两个倍数相等,即速度和分配比成正比,则为膜相控制;如分配比增大而传质速度不变,则为外水相扩散控制;如速度增加倍数小于分配比增加倍数,则为混合控制.在混合扩散控制时还给出了估算不同过程扩散的相对阻力,并对我们过去研究过的体系作了验证,得到一些有意思的结果.还对ln(C0/C)~t有无直线关系作了探讨  相似文献   

5.
表面活性剂对液膜分离传质性能的影响   总被引:3,自引:0,他引:3  
研究了不同表面活性剂组成的液膜体系在分离过程中的传质、溶胀和渗透等性能,分别考查了聚胺型表面活性剂L-113A和LMA-1及酯型表面活性剂Span80对含P204载体液膜体系迁移镧(Ⅲ)的影响,以及L—113A、L—113B和EM-301对无载体液膜体系富集氨氮的影响.实验表明,因表面活性剂不同,造成乳状液膜体系在分离富集镧或氨氮时,分离传质性能相差较大,LMA—1—P204-煤油的液膜体系对镧具有最大的迁移能力。迁移率97.4%;而L-113A-膜相添加剂-煤油的液膜体系对氨氮的溶解渗透能力最大。迁移率为86.4%.另外,对因表面活性剂结构不同而造成油水界面黏度的差异以及对传质速率的影响,从乳状液膜和自组装双分子液膜等方面进行了探讨.  相似文献   

6.
中空纤维膜萃取的传质特性及其过程强化   总被引:2,自引:0,他引:2  
膜萃取是膜过程和液液萃取过程相结合的一种新型分离技术.与通常的液液萃取过程不同,膜萃取传质中没有相的分散过程,具有其特殊的优势.文中详细介绍了中空纤维膜萃取的传质特性及其过程强化的研究进展.  相似文献   

7.
乳状液膜法分离氨基酸的动力学   总被引:2,自引:0,他引:2  
探讨了含载体P2 0 4 (磷酸二异辛酯 )的液膜体系用于苯丙氨酸促进运输的动力学行为 .采用液滴法装置 ,控制实验条件 ,测定了内相氢离子浓度随时间的变化 ,适用于有机相界面的化学反应对溶质传递的影响 ,并将计算的结果同实验相比较 ,建立了水相 -有机相界面化学反应对溶质传质具有决定作用时的传质模型  相似文献   

8.
同级萃取反萃膜过程的研究   总被引:5,自引:5,他引:0  
本文研究了同级萃取反萃膜过程的传质性能。使用的膜器是一种特制的中空纤维膜器。实验中采用了三种不同的体系,反萃液为10%NaOH和清水。本文建立了同级萃取反萃膜过程传质模型,模型计算值与实验测定的总传质糸数值相吻合。10%NaOH膜反萃的加入明显提高了过程的分离效率。  相似文献   

9.
本文研究了同级萃取反萃膜过程的传质性能。使用的膜器是一种特制的中空纤维膜器。实验中采用了三种不同的体系,反萃液为10%NaOH和清水。本文建立了同级萃取反萃膜过程传质模型,模型计算值与实验测定的总传质系数值相吻合。10%NaOH膜反萃的加入明显提高了过程的分离效率。  相似文献   

10.
中空纤维封闭/流动液膜提溴   总被引:1,自引:0,他引:1  
以煤油为液膜相,与吸收液(0.4 mol/L甲酸钠溶液)和含溴原料液组成实验物系,利用聚丙烯单壳程一双管程中空纤维膜组件、聚砜中空纤维膜组件,分别实现封闭液膜和流动液膜体系,利用液膜分隔原料液和吸收液,考察含溴原料液、吸收液和煤油流量对提溴效果和传质系数的影响;讨论了两种液膜体系提溴过程的特点,并与气态膜法提溴过程进行了比较.  相似文献   

11.
Extraction of dyes from aqueous solution was studied using liquid emulsion membrane. Study was carried out using two dyes, namely, crystal violet (CV) and methylene blue (MB). Extraction of single component system of each dye and their binary mixture were investigated. Liquid emulsion membrane was formed using n-heptane as membrane phase, sodium hydroxide solution as the internal phase and dye solution as the external phase. Surfactant span 80 was used as the emulsion stabilizer. Effects of concentration of span 80, concentration of NaOH, stirring speed, composition of feed solution and the volume ratio of the oil phase to the aqueous phase (O/A) were studied in detail both for single and binary system. Maximum extraction of MB was found to be 99% and that for CV was about 95% in single component system. In binary mixture, these values were 97% and 90%, respectively.  相似文献   

12.
液膜法萃取青霉素的研究   总被引:20,自引:3,他引:17  
介绍了乳状液膜法萃取模拟发酵液中青素的研究工作,考究了混合槽中液膜组成、试剂比、油内比、乳水比及外水相PH变化对传质过程的影响,找出了一个较为适宜的液膜组成及室浊下适宜操作的萃取工艺条件。  相似文献   

13.
液膜法去除废水中的氨氮污染   总被引:25,自引:0,他引:25  
研究了用乳状液膜法去除废水中的氨氮污染.选择了液膜体系,考察了各种因素对氨氮去除率的影响.结果表明,由表面活性剂、民用煤油及膜增强剂组成的膜相,稀硫酸的质量分数10%的内相组成的液膜体系,当乳水比ReW=1∶10、接触时间为8分钟时,可使氨氮含量在1000mg/L以上的废水,一级去除率达97%以上,处理后的废水符合排放标准  相似文献   

14.
采用乳化液膜法对含H2S的乙二醇溶液进行脱硫研究.膜相由膜溶剂煤油、表面活性剂、流动载体乙二胺、膜稳定剂液体石蜡组成;内相试剂为NaOH.考察了传质时间、表面活性剂的种类及浓度、流动载体浓度、内相NaOH浓度、膜溶剂与内相试剂之比、乳化液与外相溶液之比、乙二醇溶液的初始硫含量以及传质搅拌速率对H2S脱除率的影响.试验结果表明,乳化液膜法用于含硫乙二醇溶液的脱硫是可行的,H2S脱除率可达到98%以上.  相似文献   

15.
We considered mass and heat transfer during nonisothermal absorption of a gas by a falling droplet with internal circulation. Gas phase is assumed to be free of inert admixtures and mass transfer is liquid phase controlled. Mass flux is directed from a gaseous phase to a droplet, and the interfacial shear stress causes a fluid flow inside the droplet. Droplet deformation under the influence of interface shear stress is neglected. Absorbate accumulation and temperature increase in the bulk of liquid phase are taken into account. The problem is solved in the approximations of a thin concentration and temperature boundary layers in the liquid phase. The thermodynamic parameters of the system are assumed constant. The system of transient partial parabolic differential equations of convective diffusion and energy balance with time-dependent boundary conditions is solved by combining the similarity transformation method with Duhamel's theorem, and the solution is obtained in a form of Volterra integral equation of the second kind which is solved numerically. Theoretical results are compared with available experimental data for water vapor absorption by falling droplets of aqueous solution of LiBr.  相似文献   

16.
Separation of aniline from aqueous solutions using emulsion liquid membranes   总被引:10,自引:0,他引:10  
An emulsion liquid membrane process is developed to separate aniline from dilute aqueous solution. Aniline (amino-benzene) is a carcinogenic chemical common in industry and industrial wastewater. Due to aniline's high boiling point (183°C) and low concentration in wastewater, more traditional methods of separation such as distillation are very energy intensive. This emulsion process is offered as a low energy alternative. All separations occur in a Rushton stirred tank. The membrane phase consists of kerosene and the surfactant sorbitan monooleate (span 80). Hydrogen chloride solution is the internal phase. This study also examines the effects of HCl concentration, aniline concentration, and the amount of emulsion on separation. Up to 99.5% of the aniline is removed from solutions containing 5000 ppm in as little as 4 min depending on process conditions. Leakage is minimal and swelling is only about 3% after 5 min of processing. Approximately 98% of the membrane phase (both kerosene and span 80) is successfully recovered and recycled by using heat and/or adding 2-propanol for demulsification.  相似文献   

17.
The extraction equilibrium of Co(II) from thiocyanate medium by CYANEX 923 (mixture of straight chain alkylated phosphine oxides) in cyclohexane was studied. The stoichiometry of the extraction reaction was postulated based on slope analysis method and the extraction constant Kex was calculated. The stripping percentage of Co(II) with sulphuric acid from the loaded CYANEX 923 was found to increase with the increase in acid concentration. The extraction of Co(II) from aqueous thiocyanate medium into emulsion liquid membrane using CYANEX 923 extractant was also studied. The influence of different parameters such as stirring speed, surfactant concentration, pH of the extractant phase, carrier concentration, internal phase stripping acid concentration, initial Co(II) concentration as well as temperature on the emulsion stability were investigated. The applicability of the emulsion liquid membrane (ELM) process using CYANEX 923 as extractant and SPAN 80 as surfactant for the removal and the concentration of Co(II) from thiocyanate solution was investigated. The results show that it is possible to recover 95% of cobalt in the inner phase after 10 min of contacting time with a concentration factor of 5.  相似文献   

18.
中空纤维封闭液膜用于乳酸分离   总被引:4,自引:0,他引:4  
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  相似文献   

19.
乳状液膜法提取亮氨酸   总被引:4,自引:0,他引:4  
研究了亮氨酸的乳状液膜提取方法.考察了外相溶液组成、内相 H+ 浓度、外相p H 值及载体用量对提取率的影响,从而确立了各影响因素的最佳值  相似文献   

20.
液膜法处理高氟废水研究   总被引:10,自引:0,他引:10  
利用N205-N1923-煤油液膜体系,CaCl2溶液作内相,对高氟废水的处理进行了研究。利用正交实验确定了影响最大的因素,并研究了各种因素对处理的影响。经30min处理,外相F^-浓度可由0.500g/L降至0.010g/L以下,可达到工业排放标准。  相似文献   

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