镍在乳状液膜体系中的迁移行为

研究了镍在乳状液膜分离体系中的迁移行为。在此分离体系中,以煤油作为膜溶剂,span80为表面活性剂,磷酸三丁酯(TBP)为载体。详细讨论了制乳时间和混合时间、span80和TBP浓度、乳水比和油内比、内相NH。和外相HCl的浓度对镍迁移率的影响,确立了最佳分离条件。     

谷氨酸在Span80-AOT-APS体系中的迁移行为

报道了谷氨酸在乳状液膜体系中的迁移行为,采用失水山梨醇单油酸酯(span80)-乙基己基琥珀酸酯磺酸钠(AOT)为表面活性剂,对氨基苯磺酸(APS)为载体,煤油为膜溶剂,氯化钾为内相试剂.讨论了制乳时间和乳液与外相混合时间、表面活性剂和流动载体浓度、内相试剂浓度、水乳比和油内比对分离效果的影响.确定了最佳分离条件为制乳...     

乳状液膜体系分离提取铜离子

以Span80-对氨基苯磺酸(APS)-NH3液膜体系分离提取Cu2+。最佳分离条件为:制乳搅拌速度3500r/min,制乳时间及乳水混合时间分别为10min和20min,乳水比和油内比分别为0.38和0.44,APS、Span80和液体石蜡浓度分别为11%、4.4%和2.2%,内相NH3和外相HCl浓度分别为4.0mol/L和0.5mol/L。用该体系分离提取了模拟样中的Cu2+。     

乳状液膜体系分离锌(Ⅱ)

研究了span80(失水山梨醇单油酸脂)-SDS(十二烷基磺酸钠)与span80-AOT(2-乙基己基琥珀酸酯磺酸钠)两种乳状液膜体系对锌(Ⅱ)分离效果的比较。分别讨论了液膜体系中表面活性剂和内相试剂浓度、乳水比和油内比对锌(Ⅱ)去除率的影响。试验了锌(Ⅱ)与共存组分的分离。     

乳状液膜法分离水中汞的研究

报道了用乳状液膜法分离汞的研究。确定了最佳分离条件；流动载体TBP（磷酸三丁酯）和表面活性剂Span80的浓度均9％，内相溶液NaOH和外相溶液HCl的浓度分别为0.4mol/L和0.02mol/L，制乳时间和混合时间分别为10min和5min，乳水比和油内比分别为0．5和0．8。     

铜在乳状液膜体系中的迁移行为

近年来膜分离技术在环境治理方面得到广泛应用。本文研究了铜在span80-TBP（磷酸三丁酯）-煤油-NH3液膜分离体系中的迁移行为。用TBP作为载体,在溶液中迁移时,在外相与膜相界面上形成中性络合物后穿过膜相,在膜相与内相界面上络合物再与NH3反应,生成铜氨络离子,释放出来的TBP又返回膜相。     

铜(Ⅱ)在双表面活性剂液膜体系中的迁移行为

乳状液膜分离技术具有快速高效、选择性强、富集比大等优点[1-4],但该技术目前大多还处在实验阶段,要实现工业化则必须解决液膜稳定性、有毒试剂的使用及二次污染等问题.表面活性剂对于乳状液膜的形成和稳定至关重要[5-7],而在液膜体系中采用复合表面活性剂,能改善液膜性能,提高膜稳定性及传质效率[8].本文研究了铜(Ⅱ)在span80-SDS-NH3液膜体系中的迁移行为.体系中无流动载体,利用内、外相中被分离物的浓度梯度促进物质迁移.当Cu2+进入内相时,与NH3产生络合反应,使内相中游离的铜离子浓度趋于零而促使其由外相进入内相,实现Cu2+与外相溶液的分离.     

皂化P204/煤油微乳体系分离L-苯丙氨酸的研究

研究了P204-煤油-NaOH组成的微乳液膜配方及其稳定性。通过该液膜体系对L-苯丙氨酸水溶液进行提取实验,考察了P204的浓度、乳水比、外水相pH值、膜相重复使用次数、分离时间等对提取效率的影响。实验结果表明,微乳液膜不仅稳定性好,无明显溶胀和泄漏,分离速度快,而且分离效果好,可自动破乳,油相可重复多次使用,对L-苯丙氨酸的一次性提取率达88.25%。     

乳状液膜法迁移及分离钯(Ⅱ)的研究

本文采用以叔胺N_{7301为流动载体、span 80为表面活性剂、煤油为膜溶剂、EDTA作内相试剂的乳状液膜体系迁移分离钯(Ⅱ)。确证了其迁移机理。实验表明在所筛选出的适宜制乳及迁移分离等最佳条件下，96%以上的Pd(Ⅱ)迁入内相，并能有效地与Cu²⁺、 Zn²⁺、Cd²⁺、Pb²⁺、Ni²⁺、Fe²⁺等离子分离。}     

PMBP为载体的乳状液膜提取钪的研究

研究了以１－苯基－３－甲基－４－苯甲酰基吡唑酮－５（ＰＭＢＰ）为流动载体的乳状液膜（ＥＬＭ）法提取钪，确定最佳液膜体系组成为０．４％ＰＭＢＰ－３％Ｓｐａｎ８０－５％液体石蜡－煤油－３ｍｏｌ／ＬＨＣｌ，Ｒｏｉ＝１：１（油内比）．Ｒｗｅ（水乳比）可达２０：１．用该体系对钪与混合稀土进行分离，钪的回收率可达９５．５％，分离系数β（ＳＣ／ＲＥ）＝３２．０。     

乳状液膜法分离水中的铬

乳状液膜法由于其独特的物理化学性质,已广泛用于金属离子的萃取分离[1～3]。本文以span80-煤油-NaOH液膜体系分离水中铬。不加流动载体,利用内、外相中被分离物的浓度梯度实现物质迁移。当Cr2O2-7进入内相时,与内相的NaOH发生反应,在内相高浓度的NaOH存在下,可保持Cr2O2-7在液膜两侧有最大的浓度梯度,促使Cr2O2-7的迁移,实现Cr2O2-7与外相溶液的分离。1　实验部分1 1　仪器与试剂D40-1型电动搅拌器(杭州仪表电机厂),78-1型磁力加热搅拌器(江苏金坛新一佳仪器厂),721型分光光度计(上海第三分析仪器厂)。铬标准溶液(100ml/L):准…     

Comparative studies on co-extraction of uranium(VI) and different mineral acid from aqueous feed solutions using TBP,TOPO and TOA

Equilibrium and kinetics of co-extraction of hexavalent uranium and mineral acids from aqueous solutions into a hydrocarbon phase (paraffin) using tri n-butyl phosphate (TBP), tri-n-octyl phosphine oxide (TOPO) and tri-n-octyl amine (TOA) has been studied. Relative rates of extraction of uranium(VI) and mineral acid by different complexing ligands were measured simultaneously using bulk-liquid membrane system. Acid extraction by complexing ligands was found to be significant. Wherever there was a possibility of the formation of the third phase, isodecanol was used as an organic phase modifier. Study revealed that isodecanol promotes acid extraction and substantially reduces distribution coefficient of U(VI) into the hydrocarbon phase. The rate of acid extraction by different ligand was in the order of TOPO > TOA > TBP–isodecanol > TBP, whereas the rate of extraction of uranium(VI) was in the order TOPO > TOA > TBP > TBP–isodecanol. A kinetic model was developed to predict concentration of acid and U(VI) in the feed, organic and the strip phase during extraction. The mass transfer coefficients for acid and metal were determined by fitting the model to the observed concentration–time data.     

Extraction of cadmium from aqueous solutions by emulsion liquid membrane (ELM) using three different carriers dissolved in a 70:30 ratio of sunflower oil to kerosene

This study explores the use of novel green emulation liquid membranes (GELMs) for the simultaneous extraction and stripping of Cd (II) from aqueous solutions. A solute is transported through the membrane due to the presence of the carrier and then concentrated in the internal phase. Soybean, sunflower, corn, and canola oils were used to form green substitutes to petroleum-based organic diluents for use as GELMs. Bis-(2-ethylhexyl) phosphate (D2EHPA), tri-butyl- phosphate (TBP), and trioctylamine (TOA) were the extractants, span 80 was the emulsifier, and HCl or H₂SO₄ was used as the stripping agent. The best conditions for maximum extraction efficiency (98.68%), stripping efficiency (97.14%), and lowest membrane breakage (0.9%) were achieved using a mixture of sunflower oil and kerosene in the ratio of 70:30. The other optimum values of the variables were: 2% (v/v) Span 80, 10 min emulsification time, 12700 rpm emulsification speed, 400 rpm of agitation speed, 5% (v/v) D2EHPA, an external phase pH was 3.5, an internal phase of 0.25 M HCl, and 5:1 of the treat ratio (external phase to emulsion) at 10 min contact time. The synthesized membrane was reused eight times, with approximately the same efficiency and no significant breakage during the first seven cycles.     

Extraction of Priority Pollutant 4-Nitrophenol from Water by Emulsion Liquid Membrane: Emulsion Stability,Effect of Operational Conditions and Membrane Reuse

This work aims to the extraction of the priority pollutant 4-nitrophenol (4-NP) from water by emulsion liquid membrane (ELM). Liquid membrane consists of a diluent (hexane) and a surfactant (Span 80). Sodium carbonate solution was used as internal aqueous phase. Effects of important experimental conditions governing the stability of the W/O emulsion were investigated. Influence of operating parameters that affects the permeation of 4-NP such as surfactant concentration, emulsification time, sulfuric acid concentration in external phase, acid type in external phase, internal phase concentration, type of internal phase, stirring speed, volume ratio of internal phase to membrane phase, treatment ratio, 4-NP initial concentration, and diluent type was examined. This study also evaluated the effect of Na₂CO₃ concentration in the internal aqueous phase on the stripping of 4-NP. Additionally, the reuse of the recovered membrane was studied. Under most favorable conditions, practically all the 4-NP and aniline (AN) molecules present in the feed phase were extracted. The recovery of the membrane phase was total and the extraction of 4-NP was not decreased. The ELM treatment process represents a very interesting advanced separation process for the removal of 4-NP and AN from aqueous solutions.