Recovery and Separation of Metal Ions from Aqueous Solutions by Solvent‐Impregnated Resins

The recovery and separation of metals from aqueous solutions is one of the research hotspots in hydrometallurgy, environment protection, analytical chemistry, etc. Much attention has been paid to solvent‐impregnated resins (SIRs) since these were firstly proposed for the extraction of metals. SIRs are characterized by high efficiency and selectivity, convenient preparation, and easy operation because they combine the unique advantages of solvent extraction and ion exchange. The preparation and features of SIRs are summarized and their applications in the extraction of various metals from solutions are reviewed. In addition, the equilibrium, thermodynamics, and sorption kinetics of the metals onto SIRs are elucidated in detail.     

Optimization of recovery of esterase from Serratia marcescens using combination of the solvent impregnated resin and aqueous two-phase extraction techniques

ABSTRACT

The performance of tunable aqueous polymer phase impregnated resins (TAPPIR) which is the combination of the solvent impregnated resin principle and an aqueous two-phase system for the separation of esterase from Serratia marcescens was evaluated in this study. Different molecular weight of polyethylene glycol (PEG) (2000, 4000 and 6000) at concentration ranging from 5% to 20% (w/w) and potassium citrate were used to construct the aqueous phase in TAPPIR technology. Optimum composition of PEG and salt for esterase partitioning was determined using response surface methodology. The optimum condition for the purification of esterase was impregnation of 25% (w/w) of PEG 2000 into 4 mm porous glass beads and extraction of esterase using 15% (w/w) potassium citrate at pH 8 containing 12% (w/w) crude loading with the addition of 4% (w/w) NaCl. Esterase from S. marcescens was successfully purified by the TAPPIR technology up to 5.32 of purification factor with a yield of 75.98%.     

Selective Recovery of Copper,Cobalt, and Nickel from Aqueous Chloride Media using Solvent Impregnated Resins

Selective recovery of copper, cobalt, and nickel from acidic chloride media was investigated with solvent impregnated resins (SIRs) containing acidic organophosphorus extractants. The adsorption of each metal with the SIR proceeds via a cation exchange mechanism. An SIR containing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (PC-88A) has high selectivity for Cu²⁺, and the order of selectivity is Cu²⁺ > Co²⁺ > Ni²⁺. Effective adsorption-elution can be achieved by chromatographic operation for the selective recovery of Cu²⁺ from a ternary metal solution. High selectivity for Co²⁺ was observed using a SIR comprising bis-2,4,4-trimethylpentylphosphinic acid (Cyanex 272) and can be effectively separated from a Co and Ni binary metal solution by column adsorption. A simple and effective process flow sheet is proposed for selective recovery of Cu²⁺, Co²⁺, and Ni²⁺ from aqueous chloride media using the two SIRs.     

Separation of Indium from Acid Sulfate-Containing Solutions by Ion Exchange with Impregnated Resins

Indium separation using ion exchange resins from acidic polymetallic and very diluted solutions are investigated. Since the selectivity of commercial ion exchange resins have proven to be too low for an effective separation from solutions with high content of other metals, Lewatit® TP 208 was impregnated with common extractants to enhance its properties. By resin impregnation with D2EHPA and Cyanex 272, not only the selective indium recovery was reached but also the resin capacity was increased approx. two times. The best loading and elution performance were shown by Cyanex 272-impregnated Lewatit® TP 208, increasing the indium purity in the eluate from 0.75 % to 85 %.     

Preparation and analysis of high capacity polysulfone capsules

Since the concept of solvent impregnated resins was introduced in the early 1980s, the technique has been applied to a limited amount of applications. The main disadvantage of the resins was that the amount of solvent inside was limited to approximately 1.5 ml/g polymer. A new generation of solvent impregnated resins is introduced. These capsules can contain up to 11.8 ml solvent/g polymer and were prepared using a modified dry impregnation technique. Due to the high solvent loading, the capacity per volume of capsule for extracting products from aqueous phases is therefore dramatically increased.     

Multistage Processing of Tunable Aqueous Polymer Phase Impregnated Resins (TAPPIR®)

A promising concept of aqueous two‐phase extraction (ATPE) is the Tunable Aqueous Polymer Phase Impregnated Resins (TAPPIR®) technology. Thereby, one phase of an aqueous two‐phase system (ATPS) is immobilized inside porous solids, which are then dispersed in the second aqueous phase. Beside extraction performance, the reusability of the impregnated solids for several cycles decides upon the competitiveness of TAPPIR®. Multistage extraction experiments using a polyethylene glycol 4000/citrate ATPS to partition lysozyme were investigated for TAPPIR® and ATPE. A stable impregnation was demonstrated for multiple cycles. Moreover, it was found that multistage extraction processes should not be designed on basis of the first extraction as the yield changes in the following stages.     

新型绿色分离体系——离子液体双水相及其在生物分离中的应用

近几年来,离子液体双水相作为一种新型绿色分离体系越来越受到关注。离子液体双水相具有粘度低、分相快、不易乳化以及对生物物质萃取率高等优点。介绍了离子液体双水相的机理以及它在生物分离中的一些应用。     

双水相萃取技术的应用进展

主要介绍了双水相萃取的基本要点及应用特点,综述了近三年来双水相萃取技术在生物工程、药物成分提取分离、环境中有害物分离测定及与其它方法配合使用等方面的应用,探讨了双水相萃取技术的应用前景.     

水性含氟涂料树脂的合成研究进展

概述了含氟涂料的发展过程,综述了水性含氟涂料树脂的种类、制备方法及合成研究进展,并展望了水性含氟涂料树脂的前景及其市场发展趋势。     

双水相萃取技术研究现状

近年来,双水相萃取(ATPE)已经发展成由计算机控制、在常规萃取设备中、能连续操作的分离技术。介绍了传统双水相体系(ATPS)和新型ATPS的特征、分相机理、工业应用的优缺点,指出寻找低成本易回收可循环利用的ATPS组成物质和对预分离物质有更高选择性的ATPS组成物质是研发新型ATPS的方向。论述了ATPS液液平衡的热力学模型、分配系数的关联方法,指出提高选择性及分离效率是ATPE应用研究的方向,指出总结分配系数影响因素规律、修正液液平衡的热力学模型是ATPE理论研究的方向。     

双水相萃取技术及其在药物分离中的应用

双水相萃取技术作为一种新型的分离技术用于药物提取分离具有广阔前景。介绍了双水相体系的组成,双水相萃取技术原理、工艺过程、应用等。     

Sorption of Citric Acid from Aqueous Solutions by Macroporous Resins Containing a Tertiary Amine Equilibria

Abstract

Experiments were conducted on equilibrium distribution of citric acid between relatively concentrated aqueous solutions and macroporous resins containing tri-n-octylamine (TOA). The equilibrium data were well described by the Langmuir isotherm equation. Chemical model analysis of the results showed that the sorption could be also explained by the formation of an acid-amine complex with general composition (acid)(TOA)_q in the resin phase. The loss of amine from the impregnated resins and the effect of temperature on equilibrium distribution were also discussed.     

乙醇/碳酸钾双水相萃取盾叶薯蓣发酵液中的2,3-丁二醇

实验考察了乙醇/碳酸钾双水相萃取盾叶薯蓣发酵液中2,3-丁二醇的分配情况,并对其工艺条件进行了优化。结果表明,当乙醇22%(质量)、碳酸钾26%(质量)时,发酵液中2,3-丁二醇的回收率达到最高值97%,此时,乙偶姻和残余还原糖的回收率为97%和87%,菌体和蛋白的去除率分别为99%和94%,而丙酮酸、柠檬酸、苹果酸、延胡索酸和琥珀酸的去除率高达100%,这为2,3-丁二醇的工业分离提供了一种新的技术。     

核桃叶黄酮类化合物的双水相与超声耦合提取

将超声波提取技术与丙醇-硫酸铵双水相分离技术进行耦合,从核桃叶中提取黄酮类化合物,提取率为13.9%。与传统的有机溶剂回流提取法(提取率14.2%)相比,该法的提取率略低,但提取过程中体系的温度不会大幅度升高,可有效地保持黄酮的生物活性,而且双水相分离使黄酮的纯度得以提高。     

双水相萃取技术的研究现状与应用

双水相萃取技术是一种高效温和的新分离技术,在生物制药、分析检测、稀有金属分析等方面均有应用,特别是在生化分离工业中,比传统的萃取方法有着更加明显的技术和条件优势.本文综述了双水相技术的基本原理、应用方向、集成技术、热力学模型等,对双水相技术目前所存在的问题以及发展前景做了简要的论述.     

双水相电泳分离氨基酸

双水相电泳是将电泳与双水相分离方法相耦合的一种新型分离技术。双水相体系因两相均富含水且界面张力低,具有良好的生物相溶性,因而在分离蛋白质等在有机溶剂中易失活和变性的有生物活性物质具有很大的优势。本文主要考察了在间歇操作过程中,双水相电泳时间、电场强度、料液初始浓度和传质面积等因素对聚乙二醇（ＰＥＧ）－葡聚糖（ＤＥＸ）－水体系中氨基酸（苯丙氨酸和这酸）的上相浓度、萃取率、和总传质量的影响,初步探讨了     

双水相萃取在黄酮类化合物分离分析中的应用

双水相萃取技术是一种新型液-液萃取技术,已应用于生物活性物质的分离。本文阐述了双水相萃取技术的基本原理与特点,并对其在黄酮类化合物分离分析中的应用进行了综述,对双水相萃取技术存在的问题与发展前景进行了简要论述。     

L35-硫酸铵双水相体系萃取水溶液中Cr(VI)

以L35-(NH4)2SO4-H2O双水相体系萃取模拟废水中Cr(VI),考察了初始Cr(VI)浓度、水相pH值、胶束电荷调节剂1812用量、萃取时间、相分离时间、L35浓度、(NH4)2SO4浓度及萃取温度对Cr(VI)萃取率的影响. 结果表明,溶液pH值对Cr(VI)萃取率和分配系数影响最大;加入1812后,Cr(VI)萃取率和分配系数明显提高;随温度升高,两者均逐渐降低;随L35和(NH4)2SO4浓度增加,Cr(VI)萃取率逐渐提高并趋于恒定;萃取和相分离时间均较短;在最佳萃取条件下,Cr(VI)单级萃取率达92%(w),分配系数达15以上. 四级错流萃取的理论计算和实验结果基本一致,Cr(VI)浓度由2 g/L降到0.5 mg/L以下,达到国家排放标准. Cr(VI)依靠其相对疏水性以增溶方式及静电引力方式进入L35胶束内部而被萃取. 用NaOH水溶液对萃取相单级反萃取,Cr(VI)反萃率达99.5%(w)以上,浓缩倍数>4.     

双水相萃取技术进展及其应用概况

双水相萃取技术是一种新型的生物分离技术,它与传统的萃取及其它分离技术相比具有操作条件温和、处理量大、易于连续操作等优点,从而使其能广泛应用于生物分离工程中。介绍了双水相的形成、双水相萃取技术的基本原理以及影响物质分配系数的因素。同时对双水相萃取技术的研究进展及其应用进行了综述,指出目前双水相萃取技术的研究进展集中表现在:廉价双水相体系的开发、新的双水相体系探索、双水相萃取技术同其它技术集成化、双水相萃取相关理论的进展等方面。双水相萃取的应用领域除了传统的生物分离领域外,还应用于金属离子的测定和分离等其它领域。     

膦(磷)类萃取剂浸渍树脂吸附重稀土的性能

利用静态法研究了5种不同膦(磷)类萃取剂的浸渍树脂在盐酸介质中对重稀土的吸附行为. 结果表明,Cyanex272与膦(磷)类萃取剂组成的双萃取剂的浸渍树脂在同等实验条件下比单一Cyanex272萃取剂的浸渍树脂对重稀土具有更好的吸附性,其中以Cyanex272与P507, Cyanex302, Cyanex923和TBP分别按体积比1:1, 5:1, 1:1, 2:1混合为最优. 吸附最佳pH值在3.0~4.0之间,吸附平衡时间为50 min,升高温度对吸附有利. 在相同实验条件下,5种浸渍干树脂Cyanex272, Cyanex272-P507, Cyanex272-Cyanex302, Cyanex272-Cyanex923, Cyanex272-TBP对重稀土的饱和吸附容量分别为20.04, 25.37, 21.87, 22.16, 38.48 mg/g.