皂化HA/煤油微乳液萃取赖氨酸的研究

研究了NaOH皂化HA/煤油微乳体系萃取赖氨酸的机理和工艺,考察了NaOH浓度、萃取时间、乳水比、外水相pH值、油相重复使用次数等对萃取效率的影响.结果表明,该微乳液萃取赖氨酸的最佳工艺条件为:油相中HA的浓度1.0 mol·L-1、NaOH浓度1.25 mol·L-1、萃取时间10 min、乳水比(体积比)1:4、外水相pH值3.0,此时,赖氨酸的一次性萃取率可达90.2%.该微乳液具有稳定性好、无明显溶胀和泄漏、萃取效率高、可自动破乳且油相可重复使用等优点.     

皂化P204微乳液膜处理含锌废水的研究

研究以皂化P204为载体的微乳液膜配方及其稳定性.采用P204/Span80/煤油/NaOH微乳体系萃取废水中Zn^2＋,考察了P204与煤油和Span80的质量比、NaOH的浓度、乳水比、外水相pH值、油相重复使用次数等因素对Zn^2＋萃取率的影响.结果表明,当P204与煤油的质量比为1：2.5,P204与Span80的质量比为1：1,NaOH浓度为1.5mol/L,乳水比为1：4（体积比）,废水pH值为5.5时,萃取10min,P204/煤油/NaOH微乳液膜对Zn^2＋萃取率可达99.72%,P204/Span80/煤油/NaOH微乳液膜对Zn^2＋萃取率可达99.98%,微乳液膜不仅稳定性好、萃取效率高,而且工艺简单、膜相可自动破乳、油相可重复使用.     

微乳液膜法萃取Cu(Ⅱ)离子的研究

采用油酸/正丁醇/碳酸钠水溶液组成的微乳体系对水相中Cu2 进行了萃取研究,考察了微乳体系组成、水相的pH、膜水比、搅拌时间以及水相中NaCl盐度等实验参数对萃取率和微乳体系乳化的影响。研究表明,当油酸︰正丁醇︰Na2CO3(1.0 mol.L-1)=5︰5︰4(体积比),油内比Roi为2.5,废水pH在1.0～1.2之间,膜水比Rew为1︰2.5,搅拌时间为6 min时,浓度为500 mg/L的Cu2 经微乳液一级萃取后,可降至0.9 mg/L,萃取率达99.80%。     

P_(204)/Span80/煤油/NaOH微乳体系萃取分离Ni~(2+)的研究

研究了以皂化P204和Span80为混合表面活性剂的微乳液配方及其稳定性,通过P204/Span80/煤油/NaOH微乳体系萃取分离N i2+的研究,考察了P204与煤油和Span80的质量比、NaOH的浓度、乳水比、外水相pH值、油相重复使用次数等因素对N i2+萃取率的影响。结果表明,当P204与煤油的质量比为1∶2.5,P204与Span80的质量比为1∶1,NaOH浓度为1.5 mol/L,乳水比为1∶5(体积比),废水pH值为5.5时,萃取10 m in,该微乳体系对N i2+萃取率可达99.9%。该微乳体系具有稳定性好、工艺简单、成本低、萃取效率高等优点。     

甜橙油微乳的制备研究

制备了水、Tween-80/L-7D(吐温80/十聚甘油月桂酸酯)、甜橙油和丙二醇的微乳液。利用三元相图,比较了Tween-80、L-7D这两种乳化剂对微乳区形成大小的影响,考察了微乳液的稳定性和粒径大小。结果表明,在该试验条件下,Tween-80更适合于制备微乳,利用三元相图配制的微乳,可自发形成且稳定性好,粒径小于100 nm。     

微乳液体系拟三元相图及其微观结构的研究

在25℃下绘制了十六烷基三甲基溴化铵(CTAB)/正辛醇/正辛烷/水的拟三元相图,研究了CTAB与正辛醇质量比分别为1∶2,1∶3,2∶3下体系的微乳区以及微乳区的变化,并采用电导率法研究了微乳液的微观结构,将整个微乳液单相区分为油包水(W/O)微乳区、水包油(O/W)微乳区和B.C.双连续区,确定了微乳液体系形成区域并比较了各质量比下的微乳区。研究结果表明:当CTAB/正辛醇的质量比为2∶3时,能够得到较大且稳定的微乳区域;在此条件下,当(CTAB+正辛醇)/正辛烷的质量比为3∶7时,微乳液区域中存在最高溶水点且微乳液区域最大。该研究从热力学相图原理上为纳米颗粒的可控制备提供了理论依据。     

微乳液体系(OP-7+OP-4)/苯甲醇/ D2EHPA/煤油/盐酸的增溶性能及其对钕的膜萃取

研究了以OP-7[壬基酚聚氧乙烯(7)醚]和OP-4[壬基酚聚氧乙烯(4)醚] 为非离子表面活性剂、苯甲醇为助表面活性剂所形成的W/O型微乳液体系(OP-7 OP-4) / 苯甲醇 / D2EHPA / 煤油 / 盐酸在不同混合表面活性剂配比、盐酸浓度、温度、NaCl浓度等条件下对盐酸的增溶性能;将微乳液作为液膜用于对稀土钕的萃取时,采用了新的膜萃取过程即微乳液/中空纤维膜接触器萃取.结果表明,微乳液对盐酸的增溶量随混合表面活性剂的亲水亲油平衡值(HLB值)以及盐酸浓度的增大而增大,随温度的升高、NaCl浓度的增大而减小.当以逆流方式萃取时,微乳液内相盐酸浓度越大,萃取率越高,但内相富集倍数减小;当微乳液流量为6 mL·min-1、料液初始浓度为200 mg·L-1、有效萃取时间为 6 min时,Nd3 的萃取率达96.3%,微乳液内相浓度富集倍数为21.2,有效萃取时间超过6 min后,萃取率基本不变,表明该非离子型微乳液对钕Nd3 具有很好的萃取和富集功能,所采用的新膜萃取过程同时具有膜萃取过程的热力学稳定性和液膜分离过程非平衡性的优点.     

T-154为载体的微乳液膜处理焦化厂含酚废水

研究了以T-154为载体的P204/煤油/NaOH微乳液膜配方及其稳定性。采用该液膜体系处理含酚废水,探讨了载体浓度、分离时间、乳水比、油相的重复使用次数等对除酚率的影响。结果表明,微乳液膜不仅稳定性好,分离速度快,除酚效率高,而且可自动破乳,油相可重复使用。当T-154在油相中的质量浓度为5%,分离时间为20m in,乳水比为1∶4,废水的pH值为5时,一次性除酚率达99.95%。将该微乳体系用于处理某焦化厂中高浓度的含酚废水,一次性除酚率均高于97%,且对高浓度含酚废水的除酚效果更佳。     

OP-10/异戊醇/煤油/NaOH微乳液体系萃取钼(Ⅵ)的研究

采用电导率法研究了OP-10/异戊醇/煤油/NaOH水溶液微乳液体系的性质,并以此微乳液体系为油相,以TOA为载体研究了萃取水溶液中钼(Ⅵ)的工艺条件。实验结果表明:异戊醇和OP-10的最佳比例为1∶1时,该微乳液体系具有最大溶水量;拟三元相图表明该微乳液体系的稳定区域与NaOH浓度关系不大;外水相中加入一定量的NaCl可有效避免萃取过程中液膜的溶胀与破裂;当外水相中HCl浓度为0.05mol/L、膜相中TOA浓度为0.04mol/L、内水相中NaOH浓度为0.04mol/L时,微乳液体系对钼的单级萃取率可达98%。     

制备纳米BaSO4的W/O微乳液体系组成及稳定性

以Triton X-100/正己醇/环己烷/水制成W/O微乳反胶团体系，通过测定体系的电导率和观察液晶相的出现确定相点绘制了各体系的拟三元相图，研究了温度、盐浓度和油相组分对W/O微乳液体系稳定性的影响.实验发现助表面活性剂与表面活性剂的配比对微乳液的稳定性有显著影响.随着温度的升高，W/O微乳液稳定区域减小，可通过升高温度对微乳液进行破乳；与以纯环己烷为油相的体系相比，油相中含有少量正己烷的体系具有更优异的性质.所得结果为利用该W/O微乳液体系制备纳米颗粒提供了基础数据.     

含二（2—乙基己基）磷酸乳状液膜对L—谷氨酸的萃取研究

本文以ＤＺＥＨＰＡ为载体,ＥＣＡ４３６０Ｊ为表面活性剂,内外相Ｈ＾＋浓度梯度为推动力,研究了Ｌ－谷氨酸在乳状液膜体系里的传输对影响液膜萃取的各因素进行了系统阐述了确定了体系的最佳膜相组成和实验条件,实现了Ｌ－谷氨酸的萃取回收。     

中空纤维支撑液膜萃取法提铟工艺比较研究

采用中空纤维支撑液膜(SLM)技术,模拟酸性铟渣浸出液,以磷酸二异辛酯(P204)、磺化煤油体积比3:7为液膜萃取相,盐酸溶液为反萃相,研究了单组件膜萃取系统、双膜组件萃取-反萃系统、双膜组件萃取-超滤系统对酸性浸出液中In的提取与分离效率。结果表明,双膜组件萃取-超滤技术可同时实现浸出液中In的提取与反萃液中In的高纯度富集,浸出液中In的提取率可达90%以上,反萃液中In含量可达浸出液中In含量的70%,In的质量分数高于90%。     

液膜对不同酸度磷矿浸出液中稀土的提取

用浓盐酸溶解富含镧、铈等稀土离子的织金磷矿,得到含稀土离子的磷矿浸出液,以P204为载体、Span80或T154作表面活性剂、磺化煤油作溶剂、盐酸作内水相解析剂制成的乳状液膜对酸解液中镧、铈等稀土离子进行提取,考察了流动载体浓度、表面活性剂种类及浓度对稀土提取率的影响及磷矿浸出液中不同浓度稀土离子在不同酸度下的分离提取情况. 结果表明,液膜中最佳载体浓度为12%(j),最佳表面活性剂浓度为4%(j),随外水相pH值增大,液膜对稀土离子的提取率提高,外水相稀土离子浓度为100 mg/L,pH=1时,其提取率可达79.93%.     

微乳液膜法萃取钕

进行了微乳液膜法萃取Nd3+的研究,考察了不同盐酸浓度时微乳液的溶水量及其对Nd3+的萃取率、内相富集浓度的影响,同时还考察了温度、料液浓度、缓冲剂对萃取Nd3+的影响.结果表明,随着盐酸浓度增大,微乳液溶水量增加;内相Nd3+富集倍数最高为24.3倍,料液Nd3+浓度相同时,内相Nd3+富集浓度和富集倍数随溶水量增加而减小,萃取率则变化不大,一般在70%～80%范围,于料液中加入缓冲剂对Nd3+的萃取率有很大影响.根据微乳液膜渗透速率方程计算了传质系数.通过在微乳液和料液之间加载一层亲水性微孔滤膜,避免了微乳液与料液直接接触所产生的乳化,内相泄漏也得到了抑制.     

微乳液的增溶、相态及微乳液/中空纤维膜萃取钕

通过考察非离子型微乳液体系（OP-4+OP-7）/ 苯甲醇/D2EHPA/煤油/盐酸中的混合表面活性剂OP-4［壬基酚聚氧乙烯（4）醚］和OP-7［壬基酚聚氧乙烯（7）醚］配比、盐酸浓度、温度和NaCl对盐酸增溶量的影响以及D2EHPA［二（2-乙基己基）磷酸］和盐酸浓度对体系相态的影响,制备了适合作为液膜分离介质的微乳液体系,同时提出了新的膜萃取过程：微乳液/中空纤维膜萃取,并用于稀土钕的萃取.结果表明,微乳液中盐酸的增溶量随混合表面活性剂HLB值以及盐酸浓度的增大而增大,随温度的升高、NaCl浓度的增大而减小;D2EHPA的加入有利于WinsorⅡ体系的形成;盐酸浓度小于6 mol•dm^-3时也可形成WinsorⅡ体系,而盐酸浓度为7 mol•dm^-3和8 mol•dm^-3时则分别形成WinsorⅢ体系或WinsorⅠ体系;将W/O非离子型微乳液通过中空纤维膜从浓度为300 mg•dm^-3的料液中萃取钕时,采用3个中空纤维膜器串连一次萃取即可使萃取率达95.3%,内相富集倍数18.1.该新膜萃取体系同时具有液膜与固膜萃取的优点,不需进行反萃操作.     

Microemulsion Liquid Membranes. I. Application to Acetic Acid Removal from Water

Abstract

A separation technique utilizing nonionic microemulsions as emulsion liquid membranes has been successfully applied to the removal of acetic acid from an aqueous feed phase. The surfactant systems were carefully characterized in order to assure that they were truly microemulsions. The effects of mixing intensity, feed concentration, treat ratio, and microemulsion viscosity on the separation kinetics were investigated. The microemulsions did not typically display leakage and had negligible swell over 5-minute duration. The reversible phase behavior of the microemulsion was utilized to demulsify the liquid membrane phase and recover the acetate ion via a temperature change of approximately 40°C. Material balances closed to within 10% and rates of separation were faster than the sampling rates when the microemulsion was fully dispersed in the aqueous feed phase.     

Response Surface Modelling and Optimization of Mercury Extraction through Emulsion Liquid Membrane

Mercury(II) is a very harmful metal, highly toxic, and carcinogenic in nature. Experiments were carried out using the emulsion liquid membrane (ELM) technique in order to evaluate the maximum extraction of mercury(II) from aqueous solutions of mercuric chloride using 3³ factorial design. The ELM consisted of di-2-ethylhexylphosphoric acid as a carrier, toluene as an organic solvent, span 80 as a surfactant, and sulphuric acid with thiourea solution as stripping phase. The three factors for the factorial design were mercury(II) concentration in the aqueous solution, that is, feed phase concentration, carrier concentration in the membrane phase, and sulphuric acid concentration in the stripping phase. The study has also highlighted the effects of various other parameters, such as pH of the feed phase and thiourea concentration on mercury(II) extraction. The optimization of the factors to obtain maximum extraction were carried out by incorporating main effect plots, interaction plots, analysis of variance (ANOVA), normal probability plots, residual plots, surface plots, and contour plots. A reduced model developed by regression analysis was suggested in which the experimental data were fitted very well. The results showed that it is possible to extract mercury(II) up to 98% from aqueous solutions at the optimum conditions.     

Separation of Zinc Ions from an Acidic Mine Drainage using a Stirred Transfer Cell–Type Emulsion Liquid Membrane Contactor

Abstract

This is a report on the separation and recovery of zinc ions from an acidic mine drainage using a stirred transfer cell‐type emulsion liquid membrane contactor. Di(2‐ethylhexyl) phosphoric acid was used as a highly selective carrier for the transport of zinc ions through the emulsified liquid membrane. A study was made of the effect on the extraction extent and initial extraction rate of the following variables: pH and initial metal concentration of the feed phase, carrier content in the organic solution, a stripping agent concentration in the receiving phase, and stirring speed in the transfer cell. The content of sulfuric acid as a stripping agent did not show in the studied range any significant influence on metal permeation through the SLM, although a minimum hydrogen ion concentration of 100 g/L is suggested in the internal aqueous solution to ensure an acidity gradient between both aqueous phases to promote the permeation of metal ions toward the strip liquor. Results show that using a pH of 4.0 in the feed acid solution, a concentration of 3% w/w_o of phosphoric carrier in the organic phase and a H₂SO₄ content of 100 g/L in the strip liquor, the extent and rate of extraction through the liquid membrane can be highly favored, pointing to the potential of this method for extracting heavy metals from many kinds of dilute aqueous solutions.     

液膜法提取浓缩氨基酸

本文研究了用液膜法提取浓缩谷氨酸。用ＴＯＭＡＣ为载体，ＥＣＡ４３６０Ｊ为表面活性剂，在适当的酸度下，以氯离子的浓度差作推动力，提取率可达６０％，浓缩倍数可达５倍。谷氨酸可以克服１１－１２倍的浓度梯度进行能动的膜输送而进入内相，这比文献报导的数值高出近一倍。