季铵盐(Aliquat 336)萃取对氨基苯磺酸的特性研究

利用季铵盐(Aliquat 336)为反应剂,在较宽的pH值条件下,研究了对氨基苯磺酸稀溶液的萃取相平衡特性;测定了反应剂浓度、稀释剂种类、盐的存在以及溶液pH值对反应萃取平衡分配系数的影响;提出了反应剂与对氨基苯磺酸负离子的阴离子交换反应机理,建立了平衡分配系数D值的表达式。结果表明,极性稀释剂不利于对氨基苯磺酸的萃取,惰性稀释剂能提供较大的萃取平衡分配系数,其顺序为:苯>四氯化碳>氯仿>正辛醇;盐的存在会降低Aliquat 336的萃取效率;与三烷基胺(Alamine 336)相比,Aliquat 336具有更宽的pH值适用范围。     

三辛胺萃取一元羧酸的平衡规律(Ⅱ)表观萃取平衡常数与规律表征

在本文（Ⅰ）报关于三辛胺（TOA）萃取甲酸、乙酸、丙酸、丁酸、戊酸、一氯乙酸、二氯乙酸、三氯乙酸、乙醇酸、乙醛酸、乳酸等11种羧酸萃取平衡特性的研究基础上,采用质量作用定律分析方法建立了TOA对一元羧酸的萃取平衡模型,拟合了模型参数——表观反应萃取平衡常数K₁₁,并获得了满意的拟合精度;提出了影响TOA萃取一元羧酸平衡的3个因素：溶质的亲油性lgP、溶质的酸性pK_a、TOA的表观碱度pK_a,B,并确定了K₁₁与这3参数的关系,经拟合实验测定的114个K₁₁,获得了一元羧酸K₁₁的关联式.为一元羧酸分离工艺中萃取剂的选择提供了指导.     

吡啶从硝酸介质中萃取铀(VI)的研究

研究了新萃取剂吡啶从硝酸介质中萃取铀的机理。考察水相硝酸浓度、萃取剂浓度、盐析剂硝酸钠以及振荡时间和温度对萃取分配比的影响 ,确定了萃合物的组成。求得萃取硝酸铀酰过程的平衡常数及反应的热力学函数。同时研究了相比的影响 ,以及稀释剂的影响。发现吡啶萃取能力在不同稀释剂中由弱到强的顺序为 :四氯化碳、氯仿、苯、甲苯、环己烷、煤油。     

吡啶从硝酸介质中萃取铀(Ⅵ)的研究

研究了新萃取剂吡啶从硝酸介质中萃取铀的机理。考察水相硝酸浓度、萃取剂浓度、盐析剂硝酸钠以及振荡时间和温度对萃取分配比的影响，确定了萃合物的组成。求得萃取硝酸铀酰过程的平衡常数及反应的热力学函数。同时研究了相比的影响，以及稀释剂的影响。发现吡啶萃取能力在不同稀释剂中由弱到强的顺序为：四氯化碳、氯仿、苯、甲苯、环己烷、煤油。     

三烷基氧膦反应萃取一元羧酸的规律

化学萃取法对有机羧酸稀溶液的分离具有高效性和高选择性.萃取剂的相对碱性是表征萃取剂性质的重要参数.选取三烷基氧膦（TRPO）为萃取剂,煤油为稀释剂,甲酸、乙酸、丙酸、丁酸、己酸、一氯乙酸、二氯乙酸、三氯乙酸、乳酸9种一元羧酸为被萃溶质,研究了溶质种类、TRPO浓度对萃取剂相对溶质的相对碱度（pK_a,BS）的影响,探索了从化学反应基本理论出发研究络合萃取平衡规律的可行性.实验结果表明,对于TRPO/煤油萃取剂体系,pK_a,BS值不随TRPO的浓度而变化;而溶质的亲油性和酸性对pKa,BS值影响显著;从基本理论出发推证的只包含溶质的pK_a以及萃取剂的pK_a,BS的描述反应萃取平衡规律的数学表达式可以预测TRPO萃取有机羧酸的平衡规律,并对水溶性较小或萃取平衡分配系数较小体系的pK_a,BS值测定提出了简单、易行的修正方法.     

三烷基氧磷络合萃取邻氨基苯酚的研究

络合萃取技术对极性有机物稀溶液的分离具有高效性和高选择性,然而对同时具有Lewis酸性和Lewis碱性两种官能团化合物的络合萃取研究得相对较少。为了探讨该技术对两性有机化合物萃取规律,今以三烷基氧磷（TRPO）为萃取剂,邻氨基苯酚为萃取溶质,研究了稀释剂种类、溶液pH值以及溶质浓度等因素对邻氨基苯酚稀溶液萃取平衡分配比的影响;根据可逆络合萃取的基本理论,提出了同时考虑萃取剂络合萃取作用和稀释剂物理萃取作用的分配比的表达式。并通过参数寻优求出邻氨基苯酚的物理萃取分配常数m和表观化学反应萃取平衡常数K。结果表明,邻氨基苯酚主要通过氢键缔合与OAP的中性分子发生络合反应而萃入有机相,其在惰性稀释剂煤油中的分配比大于其在极性稀释剂正辛醇中的分配比。     

三辛胺萃取草酸的机理

选择草酸稀溶液为萃取对象 ,采用三辛胺 (TOA)为络合剂 ,正辛醇为稀释剂 ,开展了TOA萃取草酸的机理研究 .以红外谱图为分析手段 ,通过测定络合剂及被萃溶质的浓度对萃合物组成的影响 ,得到其萃合物以 1∶1和 1∶2 (酸 :碱 )两种形式存在于有机相中 ;并通过萃取平衡实验 ,获得了TOA萃取草酸的平衡特性 ,进一步验证了萃合物组成 .以此为基础建立了草酸与TOA两种萃合比情况下的数学模型 ,拟合求得了K₁₁及K₁₂ ,其中 1∶2萃合物的化学萃取平衡常数远远小于 1∶1的相应值     

乙醇酸与乙醛酸的萃取分离

以乙醇酸和乙醛酸的稀溶液为分离对象,采用三烷基氧磷 (TRPO)为萃取剂、甲基异丁基酮 (MiBK)为稀释剂,研究了单、双溶质有机酸的萃取分离特性,测定了TRPO、有机酸的浓度等因素对单、双溶质有机酸萃取平衡的影响,在适当假定的基础上,建立了描述TRPO萃取乙醇酸、乙醛酸单、双溶质特性的数学模型.结果表明,随TRPO浓度的增大,分离系数β_{（glycolic /glyoxylic）}由小于1逐渐增大至大于1,乙醇酸与TRPO的萃合物有1∶1和1∶2两种形式,采用单溶质萃取反应平衡常数预测双溶质萃取的结果,预测值与实验值相当接近.同时,还对三烷基胺、磷酸三丁酯等萃取剂分离乙醇酸和乙醛酸的特性进行了讨论.     

三辛胺萃取一元羧酸的平衡规律(Ⅰ)萃取平衡特性

以三辛胺（TOA）为反应萃取剂,正辛醇、甲基异丁基酮（MiBK）、正己烷、四氯化碳和氯仿为稀释剂,甲酸、乙酸、丙酸、丁酸、戊酸、一氯乙酸、二氯乙酸、三氯乙酸、乙醇酸、乙醛酸、乳酸为被萃溶质,开展了萃取平衡特性的实验研究.结果表明,羧酸的亲油性和酸性是影响TOA萃取羧酸的关键参数.萃取平衡条件下,羧酸的酸性差别较小时,TOA的负载率主要取决于羧酸的亲油性lgP,且lgP越大,TOA负载率越高;羧酸的酸性差别较大时,TOA的负载率主要与羧酸的酸性pK_a有关,且pK_a越小,TOA负载率越高.稀释剂种类、TOA浓度对TOA的表观碱度和TOA的负载率有影响,TOA负载率Z＜1时,稀释剂对羧酸萃取平衡的促进作用为正辛醇≥氯仿＞MiBK＞四氯化碳 ≥ 正己烷,且TOA的负载率随TOA浓度的增大而减小.TOA的表观碱度是定量表现萃取剂在萃取分离环境中性质的重要参数.     

草酸与乙醛酸的萃取分离

以草酸和乙醛酸的稀溶液为分离对象 ,采用三辛胺 (TOA)为萃取反应剂、正辛醇为稀释剂 ,研究了单溶质、双溶质有机酸的萃取分离特性 ,测定了溶液pH值、萃取反应剂的浓度等因素对双溶质有机酸萃取的影响 ,提出了萃取的化学反应发生在有机相中的假定 ,建立了TOA萃取草酸的数学模型 .实验结果表明 ,草酸与TOA的萃合物有 1∶1和 1∶2两种形式 .在本实验的条件范围内 ,草酸的分配系数较乙醛酸大 ,且随溶液pH值的增大而下降 ,草酸对乙醛酸的分离系数随pH值的增大而减小 .随萃取反应剂浓度的增大 ,两酸的分配系数皆随之增大 ,分离系数也随之增大 ,而且对于高浓度的萃取反应剂在较高的溶液pH值下草酸仍具有较大的分离系数 .采用单溶质萃取反应平衡常数及纯稀释剂中双溶质的分配系数预测双溶质萃取的结果 ,预测值与实验值相当接近     

三烷基胺萃取氨基磺酸及其废水的特性研究

p-Amino benzene sulfonic acid (PABSA) is selected as the solute with amphoteric functional group, Lewis acid and Lewis base, to be separated from its dilute solutions. An aliphatic, straight chain amine, Alamine 336, is used as the extractant, and kerosene, 1-octanol, chloroform, butyl acetate and benzene as the diluent. The effects of pH value of solution, extractant concentration, salt and types of diluent on the distribution coefficient, D, are studied. There is a peak of D value with pH value of solution, the polar diluents are favorable for extracting PABSA, and the salt in aqueous phase reduces values of D apparently. The extraction equilibrium is described using the mass action law, and the calculated data according to the proposed model agree with the experimental data well. Further, the extraction behavior for other amino benzene sulfonic acids, 1-amino-8-naphtol-3,6-disulfonic acid (H acid) and 4,4′-diaminostilbene-2,2′-disulfonic acid (DSD acid), is investigated in a wide pH value region. Finally. H acid and DSD acid are successfully removed from wastewater by the extraction with Alamine 336.     

三烷基氧磷萃取对氨基苯酚的性能

以三烷基氧磷(TRPO)为反应萃取剂,研究了稀释剂种类、溶液pH值等因素对对氨基苯酚稀溶液反应萃取分配系数(D)的影响,提出了同时考虑反应萃取和物理萃取作用的分配系数的表达式.结果表明：TRPO对对氨基苯酚的萃取主要通过与其中性分子的氢键缔合和溶剂化效应实现,D值的变化与中性分子的摩尔分数有关;稀释剂的极性对对氨基苯酚的萃取影响较小;除20%TRPO/正庚烷体系外,拟合实验数据得到的表观萃取平衡常数变化较小;体系的物理萃取分配常数则随TRPO浓度的增大而增大,且符合稀释剂和TRPO的物理萃取能力的简单加和;酸性、碱性和中性的反应萃取剂都可有效地萃取对氨基苯酚,萃取能力为二(2-乙基己基)磷酸＞ TRPO ＞ 三烷基胺,相应的操作pH值为2～3、4～5和6.5～7.5,应用时可根据体系的pH值范围选用相应的萃取剂,而不必调节溶液的pH值.     

Purification and Concentration of Xylose and Glucose from Neutralized Bagasse Hydrolysates Using 3,5‐Dimethylphenylboronic Acid and Modified Aliquat 336 as Coextractants

Abstract

Experimental trials of the extraction of xylose, glucose, and fructose from aqueous solutions were conducted using 3,5‐dimethylphenylboronic acid (DMPBA) and modified Aliquat^® 336 (MA) as combined extractants dissolved in Exxal^®10 diluent. MA was produced by contacting an Aliquat 336/Exxal 10 solution with a concentrated caustic soda solution so that the quaternary ammonium ions of Aliquat 336 would ion pair with hydroxide ions. The DMPBA/MA/Exxal 10 organic solution containing equimolar amounts of MA and DMPBA was contacted with a neutral aqueous solution containing one of glucose, xylose, or fructose and the extraction isotherms were determined. The molar ratio of DMPBA:sugar in a fully loaded organic solution was 2:1. The use of the MA instead of Aliquat 336 enabled significant proportions of the sugars to be extracted from aqueous solutions over a wide pH range (～2–11). Loaded organic solutions were stripped using aqueous hydrochloric acid solutions. Complete recovery of the sugar was possible by ensuring sufficient acidity was available in the strip solution. Solutions of MA in Exxal 10 were also found to extract sugar, although to a lesser extent than when DMPBA was included. Extraction of xylose and glucose from solutions derived from the acid hydrolysis of bagasse was performed. By varying the volumetric ratio of strip to organic phases, strip solutions with xylose concentrations up to 4× that of the original hydrolysate were produced while reducing the concentration of the undesirable acid soluble lignin by up to 90%. Hence, this process has the potential to produce high concentration monosaccharide solutions suitable for direct fermentation.     

Predispersed solvent extraction of negatively complexed copper from water using colloidal liquid aphron containing a quaternary ammonium salt

Negatively complexed copper ion by complexing agent like EDTA (Ethylenediaminetetraacteic acid) was removed by predispered solvent extraction (PDSE) using colloidal liquid aphrons (CLAs) made out of Trioctylmetylammonium chloride (Aliquat 336) diluted with nonpolar kerosene. PDSE was found to have higher mass transfer rate than conventional solvent extraction under experimental conditions without mechanical mixing. The effect of type of water-soluble surfactants, phase volume ratio (PVR), concentration of anionic Sodium Dodecyl Benzene Sulfonate (SDBS) on PDSE was investigated. In addition, the effect of anionic SDBS on back extraction in PDSE was also studied. Under experimental conditions with enough mechanical mixing, the amount of copper transferred to Aliquat 336 core from the pregnant phase was compared in both PDSE by using anionic SDBS and conventional solvent extraction. It is concluded that PDSE using Aliquat 336 CLA can be used for treatment of negatively complexed copper without the influence of surfactant. To optimize CLAs-based process, stability of CLAs containing a quaternary ammonium salt Aliquat 336 diluted with kerosene in the continuous phase was investigated by measuring the volume released to surface. To destabilize CLAs, H⁺, OIL were added. Stability of CLAs was estimated by comparing the half-life obtained. Break-up of destabilization follows pseudo-first-order reaction kinetics at low ionic strength. But, pseudo-first-order model cannot be applied to a region of high ionic strength.     

The extraction of lactic acid by emulsion type of liquid membranes using alamine 336 in escaid 100

The extraction of lactic acid from aqueous solutions through an emulsion liquid membrane containing Alamine 336 as carrier was investigated. The influence of mixing speed, diluent type, surfactant concentration, extractant concentration, feed solution pH, stripping concentration, phase ratio, and feed concentration were examined. Liquid membrane consists of a diluent (n‐heptane, toluene, kerosene, Escaid 100, and Escaid 200), a surfactant (Span 80) and an extractant (Alamine 336), and Na₂CO₃ were used as a stripping solution. It is possible to extract 91% of lactic acid from aqueous solutions using Alamine 336 in Escaid 100, as an extractant and a diluent respectively.     

Extraction Equilibria of 4-Hydroxypyridine using Di (2-ethylhexyl) Phosphoric Acid

Extractions of 4-Hydroxpyridine (4HP) from aqueous solutions using Di(2-ethylhexyl)phosphoric acid (D2EHPA) as extractant in 1-octanol and kerosene were studied. The factors that affected the distribution coefficient (D), such as equilibrium pH, the concentration of D2EHPA, and the type of diluents were discussed. The interaction mechanism between 4HP and D2EHPA was validated by infrared spectroscopic analysis. D increased with the increase of the concentration of D2EHPA and peak values appeared at equilibrium pH = 3.6–5.0. D in the polar diluent (1-octanol) was much higher than those in the non-polar diluent (kerosene). The extraction reaction was found to be a proton-transfer process and D2EHPA mainly reacted through its –OH with –N– of 4HP. The apparent reactive extraction equilibrium constants K ₁₁ and K ₁₂ were obtained by fitting the experimental data of extraction equilibrium. By comparing calculated D values from the proposed model with the experimental ones, the accuracy of the proposed model was examined.     

Synergistic Solvent Extraction and Transport of Zn(II) and Cu(II) across Polymer Inclusion Membranes with a Mixture of TOPO and Aliquat 336

Separation of zinc(II) and copper(II) ions from aqueous solutions by synergistic extraction and transport through polymer inclusion membranes (PIMs) has been investigated. A mixture of trioctylphosphine oxide (TOPO) and trioctymethylammonium chloride (Aliquat 336) was used as a selective extractant as well as an ion carrier in polymer membranes. The effects of hydrochloric acid concentration in the aqueous phase and extractants concentration in the organic phase on the separation process of zinc(II) and copper(II) ions have been studied. Zn(II) ions were successfully separated from Cu(II) ions in solvent extraction process using 0.025 M TOPO and 0.06 M Aliquat 336 in kerosene. Polymer inclusion membranes (PIMs) containing a mixture of TOPO and Aliquat 336 as the ion carrier have been prepared and the facilitated transport of Zn(II) and Cu(II) ions has been studied. The influence of membrane composition on the transport kinetic of Zn(II) and Cu(II) has been evaluated. Zn(II) ions were preferably transported from the aqueous solutions containing Cu(II) and above 87% of Zn(II) ions were effectively recovered from the 0.5 M HCl solution as the source phase through PIM into 0.5 M H₂SO₄ as the stripping phase.