Penicillin G extraction from model media using an emulsion liquid membrane: Determination of optimum extraction conditions

Penicillin G extraction by an emulsion liquid membrane (ELM) was investigated. The effects of surfactants, diluents, and carrier mixtures, together with their combined effects on the initial extraction rate and the emulsion stability were examined. Surfactants, diluents, and carriers used were Span80 (sorbitan monooleate)/ECA4360J (nonionic polyamine), n-butyl acetate/kerosene, and DOA (dioctylamine)/Amberlite LA-2 (secondary amine), respectively. The optimum extraction conditions were found to be 20% (v/v) of Span80 in ECA4360J as a surfactant, kerosene as a diluent and Amberlite LA-2 as a carrier.     

Penicillin G extraction from model media using an emulsion liquid membrane: A theoretical model of product decomposition

To confirm the applicability for the extraction of penicillin G by an emulsion liquid membrane (ELM), the degree of decomposition of penicillin G during extraction was theoretically calculated. Decomposition was less than 1% provided that the initial sodium carbonate concentration in the internal phase was correctly determined, which proved the applicability of the ELM process. The procedure to determine the initial carbonate concentration in the internal phase was also described in order that the pH in the internal phase should be within the relatively stable range for penicillin G at the end of the extraction.     

乳状液膜法提取卤水中的溴

采用兰-113B作为表面活性剂，煤油作为膜溶剂，以碳酸钠为内相试剂，石蜡作为增稠剂，对乳状液膜体系进行了提取卤液中溴的研究。对迁移机理进行了探讨，确定了制乳、分离等最佳操作条件为：表面活性剂兰-113B用量为3％-4％（体积分数），液体石蜡加入量为2％（体积分数），c（Na2cO3）=0．04—0．10mol／L，制乳搅拌速度800～1000r／min，制乳时间7—9min，油内比（V油相／V内相）=5：5，浮水比（Ve／Vw）=1：25，分离时间为7～10min。在最佳操作条件下，乳水中溴的提取效率可达到98％，经过破乳，溴的回收率可以达到95％。     

Efficient recovery of phenol from phenolic wastewater by emulsion liquid membrane

The recovery of phenol from phenolic wastewater by emulsion liquid membrane (ELM) was investigated. The W/O emulsion was prepared with kerosene, Span−80, carrier, liquid paraffin, and NaOH solution. The effects of NaOH concentration, oil–internal solution ratio, shearing speed, Span−80 concentration, and carrier type and concentration on emulsion breakage were studied. In the single factor experiments of stability of W/O emulsion, the lowest percentages of emulsion breakage were achieved at a NaOH concentration of 0.03 g/ml, an oil–internal solution ratio of 2:1, a shearing speed of 1500 r/min, a Span−80 concentration of 8%, a tributyl phosphate (TBP) concentration of 0.8%, and an ethyl acetate concentration of 0.8%, respectively. Then, the effects of nine factors on extraction efficiencies of phenol were investigated. This indicated that the effects of shearing speed, oil-internal solution ratio, emulsion-external solution ratio, liquid paraffin concentration, and mixing speed on extraction efficiencies of phenol were limited. However, the carrier concentration, NaOH concentration, Span−80 concentration, and phenol concentration had important impacts on the extraction efficiency of phenol. The extraction efficiency of phenol could reach 99.7%. Besides, the results of orthogonal experiments indicated that during the extraction of phenol by ELM, the order of importance of factors was NaOH concentration > emulsion-external solution ratio > volume fraction of Span−80 > volume fraction of TBP. After extraction, the recycled emulsion with Span−80 could not easily be effectively demulsified through heating, which only provided the highest demulsification efficiency of 18.2%. However, the recycled emulsion could be effectively demulsified through centrifugation, which could get the highest demulsification efficiency of 86% at a centrifugal rotational speed of 2000 r/min and a centrifugal time of 25 min.     

Membrane stability and enrichment of nickel in the liquid emulsion membrane process

The parameters affecting the stability of a liquid emulsion membrane (LEM) for enrichment of nickel were studied. The liquid membrane is made up of a carrier (di‐2‐ethylhexylphosphoric acid), organic diluent and an emulsifying agent (sorbitan monooleate). Swelling of the internal phase during extraction results in breakage of the emulsion. The role of pH is very important in the LEM process for extraction of nickel. A significant decrease in swelling was observed by maintaining the pH of the feed phase constant during extraction. A lower osmotic pressure difference between the external and internal phase brings about lower changes in the swelling and membrane breakdown. © 2000 Society of Chemical Industry     

Extraction rates of amino acids by an emulsion liquid membrane with tri-n-octylmethylammonium chloride

The extraction rates of amino acids from alkaline aqueous solution into an emulsion liquid membrane containing tri-n-octylmethylammonium chloride as a carrier and Paranox 100 as an emulsifier were measured using a stirred transfer cell. The effects of agitation speed (0·33–0·66 rev s⁻¹), amino acid concentrations (0·5–50 mol m⁻³) and temperature (10–45°C) on the extraction rates were examined. The results were analyzed by a double-film model. The mass transfer coefficients of amino acids (0·26–1·58×10⁻⁵ m s⁻¹) and their complexes (0·60–1·72×10⁻⁵ m s⁻¹) were found to correlate well with the hydrophobicities of the amino acids. It was found that the surfactant layer influenced the mass transfer processes of both amino acids in the aqueous film and their complexes in the organic film. The permeation of amino acids with a large hydrophobicity through the emulsion liquid membrane was promoted by both high distribution and larger mass transfer rates. © 1998 Society of Chemical Industry     

Membrane‐liquid emulsion membrane process using a liquid emulsion membrane process using methane sulfonic acid as a strippant

The application of a liquid emulsion membrane (LEM) process in the recovery of zinc from aqueous solutions is discussed. The role of a stripping agent is very important in the LEM extraction process. Various stripping agents, such as hydrochloric, sulfuric, nitric and methane sulfonic acids, were tested for the stability of membrane. Methane sulfonic acid outperforms the other acids as a strippant. Further importance was given to the stability of the liquid emulsion membrane during the extraction process. The important variables affecting the LEM permeation process of zinc in a mechanically agitated contactor (MAC), such as residence time for extraction, speed of agitation, organic diluents, surfactant concentration and internal strip acid concentration, were systematically investigated. Emulsion swelling and breakage that occurred during these investigations were also described. Finally, the static mixer (SM) device was shown to have a very good potential for LEM extraction of zinc as it outperforms MAC.     

Separation of di- and tripeptides with solvent extraction and an emulsion liquid membrane

The extraction equilibria of various di- and tripeptides with di-2-ethylhexylphosphoric acid (D2EHPA) were studied at low pH values. The complex extracted to organic phase consisted of one molecule of peptide and two molecules of D2EHPA dimer. The extraction constants of the peptides correlated well with the distribution coefficients of peptides between 1-octanol and water, which is a measure of hydrophobicity. The permeation rates of peptides through an emulsion liquid membrane were examined by using D2EHPA as a carrier, Span 80 as an emulsifier and kerosene as a diluent. The rates varied considerably with peptide type, depending upon the hydrophobicity.     

乳状液膜法处理苯胺废水的实验研究

采用乳状液膜法处理苯胺质量浓度为1 000 mg/L的模拟废水,通过高速分散器制乳、搅拌器提取等操作,得到稳定的W/O/W的乳状液膜体系.考察了膜增强剂质量分数、表面活性剂质量分数、内水相盐酸浓度、外水相pH、乳水比等因素对苯胺传质速率和提取率的影响,并得到各因素的适宜操作范围.     

乳化液膜法提取废水中的阿司匹林

针对阿司匹林（ASA）结晶母液经处理后产生的废液,采用搅拌和超声结合的方法制备了乳化液膜体系来回收ASA。以环己烷为膜溶剂,Span80做表面活性剂,石蜡做膜稳定剂,氢氧化钠（NaOH）为内水相,研究了表面活性剂浓度、内水相NaOH浓度、内水相类型、外相pH、油内比、乳水比、搅拌速度、膜溶剂类型、盐浓度、ASA初始浓度等试验条件对ASA萃取效果的影响,并进行了破乳研究。结果表明：在最佳实验条件下[环己烷90%（质量分数）、Span80 6%（质量分数）、C（NaOH）=0.1mol/L、油内比1：1、水乳比1：4、搅拌速度200r/min、ASA初始浓度500mg/L],不对外相进行pH调节时,15min后ASA的萃取率可高达97.4%。对实验后的乳液进行离心破乳,20min后破乳率可达72.9%,破乳后的油相重复利用5次后,对ASA的提取率仍在76%左右。     

乳状液膜法处理含酚水溶液的研究

采用Span80、石蜡、NaOH所组成的乳状液膜体系进行含酚废水处理。讨论了NaOH含量、水乳比对提取率的影响并得出较优条件。     

表面活性剂对乳状液膜分离效率的影响

综述了基于表面活性剂的乳状液膜分离技术的原理,包括不含流动载体的I型传递机理和含流动载体的Ⅱ型传递机理;介绍了表面活性剂的种类、浓度对乳状液膜的稳定性、分离效率的影响;提出了使用乳状液膜分离技术时选用表面活性剂的原则,并展望了乳状液膜分离技术的发展前景。     

乳化液膜法脱除磷酸中镉的研究

镉是磷酸中的有害杂质之一,其对环境的污染和对人体的毒害日趋严重,所以必须控制磷酸中镉等有害杂质的含量。用乳化液膜法除去磷酸中的镉,采用单因素实验法,重点考察了表面活性剂Span-80,T151,T154及用量、萃取剂TBP,P204及用量、萃取时间对脱除磷酸中镉的影响。结果显示：表面活性剂T154用量为2.0 mL及萃取剂P204用量为2.0 mL时,乳化液膜具有较好的稳定性,且萃取时间为15 min时,从磷酸中除镉的效果最优。     

乳状液膜法萃取废水中氰化物的特性

针对氰化废水的特点,以三正辛胺（TOA）为载体、煤油为膜溶剂、液体石蜡为膜助剂、NaOH水溶液为内水相,采用乳状液膜技术处理工业废水中的氰化物。重点考察了表面活性剂用量、流动载体用量、内相液NaOH浓度等因素对氰化物萃取率的影响规律。研究结果表明：当TOA体积分数为2%、表面活性剂Span-80体积分数为3%、液体石蜡体积分数为1%、内水相NaOH质量分数为2%、油内比为1︰1、乳水比为1︰7、萃取时间为15min时,氰化废水中氰化物的萃取率达到95%以上。在实验得出的最优条件下,考察最优条件对初始浓度不同的实际废水的适用范围,分别对初始浓度为322.23mg/L、483.35mg/L、644.46mg/L和966.70mg/L的氰化废水进行处理,可得该体系下处理氰化废水的较佳的浓度范围为300～500mg/L,氰化废水中氰化物的萃取率可达到95%以上。综上所述,乳状液膜法在工业上具有良好的应用前景。     

乳化液膜技术分离湿法磷酸中铁的研究

采用乳化液膜法对湿法磷酸中铁的分离进行了研究。正交实验结果表明,在实验范围内,载体对除铁率影响最大,溶剂和反萃取剂的影响相对较小;较优的液膜物质组成为:N205为表面活性剂,CH3(C8H17)3NC l为流动载体,环己烷为膜溶剂,盐酸为反萃取剂。在实验条件下,随表面活性剂量和载体量的增大,除铁率都是先增加后降低;当盐酸浓度小于3 mol/L时,除铁率是随着盐酸浓度的增加而增加的;但是当盐酸浓度太大时,由于液膜的破碎率上升,导致除铁率反而降低。     

乳化液膜法制备草酸锌微细颗粒

采用乳化液膜法制备出草酸锌微细颗粒,乳化液膜体系以煤油为油相,以含量高于95%的二-(2-乙基己基)磷酸酯为载体,选取丁二酰亚胺类表面活性剂T155为膜相稳定剂,内、外水相分别为草酸和硝酸锌溶液,外水相Zn2 透过膜相与内水相草酸结合生成草酸锌微细颗粒。反应在40min时基本平衡,Zn2 萃取率达到90%。实验考察了反应条件对产物粒径的影响,研究表明,粒径随表面活性剂用量的增加、油水比(O/A)的增大而减小,外水相Zn2 浓度的降低可以有效地减小颗粒的粒径。TG、SEM和XRD分析证明合成产物是含两个结晶水的均匀草酸锌颗粒。将制得样品在500℃下煅烧2 h得到粒径均匀的六方纤锌矿晶系ZnO颗粒。     

乳状液膜分离技术的发展与应用

乳状液膜分离技术综合了固体膜分离法和溶剂萃取法的特点,是一种新兴的节能型分离手段。介绍了乳状液膜的组成和分类,并对其传质机理和分离过程中的影响因素进行了分析。对乳状液膜在废水处理和冶金工业方面的应用进行了具体介绍。     

乳状液膜法处理苯基胍废水的试验研究

研究了苯基胍废水的乳状液膜处理方法,选择了最佳的液膜体系,考察了各种因素对COD_Cr去除率的影响。结果表明:以w（表面活性剂L-113A）为3%、φ（添加剂）为6%、φ（盐酸）为10%、油内比R_oi为2:1的液膜体系,当乳水比R_cw=1:8、外水相pH值为8～9、传质15min,可使苯胺和苯基胍含量分别为2504mg/L和5985mg/L的苯基胍废水,去除率达99%以上,同时COD_Cr去除率达74.5%。     

乳化液膜技术研究进展

介绍了乳化液膜技术的分离机理及在金属离子的回收与提取、废水处理、发光粉与纳米材料制备和生物医学等方面的研究进展。详细叙述了各应用研究中所用的膜溶剂、表面活性剂、载体和内相试剂的种类以及分离效果。最后指出了制约乳化液膜技术工业化应用的问题及研究方向。