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1.
Partition behavior of penicillins G and V was studied in a novel three-liquid-phase extraction system, which is composed of butyl acetate (BA), polyethylene glycol (PEG), ammonia sulfate [(NH4)2SO4] and water (H2O). The main components in the top, middle and bottom phases are butyl acetate, polyethylene glycol aqueous solution and ammonia sulfate aqueous solution, respectively. Some parameters such as partition coefficients Di/j and mass fractions Ei of penicillins G and V were determined at the room temperature, respectively. Experimental efforts have been made to investigate the partition behavior of penicillin in the three-liquid-phase extraction system, including initial concentrations of phase-forming components [PEG and (NH4)2SO4], PEG molecular weight, pH, initial concentration of penicillin. The results indicated that penicillins G and V have the similar partition behavior. They preferentially distribute into the middle phase with the increase of initial concentration of phase-forming components and into the top phase with the decrease of pH, while partition coefficient Dm/b is hardly affected by pH value. The variation of PEG molecular weight has little effect on mass fractions of penicillin. The increase of initial concentration of penicillins G and V could lead to the increase of Dt/b, Dm/b and the decrease of Dt/m, while their mass fractions in all phases were almost independent on their initial concentrations.  相似文献   

2.
A novel extractant mixture, di-2-ethylhexyl phosphate (DEHPA) plus HX, was proposed and tested for recovering gallium from sulfate solution. It was found that the extraction capacity of DEPHA for gallium from sulfate solution could be enhanced significantly due to the synergistic effect of acidic extractant HX. Gallium extraction is negligible below pH 0 and highly sensitive to pH of aqueous phase in the range from 0 to 1, and satisfactory extraction can be gained at pH>1. More than 96% Ga extraction was obtained using 15% DEHPA plus 2% HX. Although Fe (Ⅲ) was found to be extracted preferentially to Ga (Ⅲ), effective extraction of Ga (Ⅲ) was possible by reducing ferric to the ferrous state prior to extraction. A loaded organic phase containing 0.48g L-1 Ga could be produced from solution of 0.12g L-1 Ga at A/O ratio of 4 : 1 via three mixer-settler operation stages. Gallium was stripped quantitatively from the loaded organic phase with l,5mol L-1 of sulfuric acid.  相似文献   

3.
Direct extraction of molybdenum from sulfate solution with synergistic extractants(mixture of D_2EHPA and TBP)was studied in the rotation column. The influence of extractant concentration and initial pH of aqueous phase was studied in the bench scale experiments. The outcomes demonstrated that the synergistic solvent extraction enhances the constancy of the extracted complexes for transfer into the organic phase. In the continuous experiments, the effect of different operating parameters such as speed of agitation, inlet solvent flow rate and inlet aqueous flow rate on the holdup, mean drop size, drop size distribution, slip and characteristic velocities and extraction percentage were examined. Modified correlations were proposed for prediction of hydrodynamic parameters with consideration of reaction extraction condition in the rotation column. Furthermore, these correlations were compared with the experimental data. According to the results, the direct extraction of Mo(Ⅵ) from aqueous solution and sulfuric media with extraction efficiency of 90.4% was obtained at higher rotor speed(240 r·min~(–1) rpm) in this column.  相似文献   

4.
This study covers the transportation of Cu(Ⅱ) ions by multi-dropped liquid membrane(MDLM) system and tri-noctylamine(TNOA) as carrier in kerosene. Batch experiments are held to obtain optimum conditions for the transportation of Cu(Ⅱ) ions such as volume of donor, organic, and acceptor phase 100 ml, p H of donor phase9.00, temperature 298.15 K, concentration of H_2SO_4 in acceptor phase 1.00 mol·L~(-1), concentration of TNOA in organic phase 5.00 × 10~(-3)mol·L~(-1)and rate of peristaltic pump 50 ml·min~(-1). Optimum circumstances of this extraction are as follows: p H of donor phase is 9.00, concentration of TNOA is 5.00 × 10~(-3)mol·L~(-1),1.00 mol·L~(-1)H_2SO_4 as acceptor phase, and flux rate is 50 ml·min~(-1). Cu(Ⅱ) ion transportation is consecutive first order irreversible reaction. Activation energy is found as 5.22 kcal·mol-1(21.82 k J·mol~(-1), this process is called as diffusion controlled system. Selective transportation of Cu(Ⅱ) ions with alkaline, alkaline earth, and different heavy metal ions at optimum conditions of single Cu(Ⅱ) extraction was conducted. According to the selective transportation Cu(Ⅱ) ions with alkaline and alkaline earth metal ions, Na~+, K~+, and Ba~(2+)ions are not detected in the acceptor phase, but 12.00% of Ca~(2+)ions is transported from donor phase to acceptor phase. At the end of the simultaneous extraction of Zn(Ⅱ), Fe(ⅡI), and Mo(VI) with Cu(Ⅱ) ions, 2.20% of Mo(VI), 0.80% of Fe(Ⅲ) and 3.60% of Zn(Ⅱ) are detected in the acceptor phase.  相似文献   

5.
In order to clarify the extraction process with saponified extractant, the solvent extraction experiments of rare earth elements(REEs), lanthanum and cerium, by using partly saponified 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester(EHEHPA, HL) from hydrochloric acidic solutions have been performed. The concentration of initial aqueous rare earth ion was in a range of 0.0010–0.1000 mol·L~(-1); EHEHPA in a range of 0.2877–0.8631 mol·L~(-1) with saponification rate of 0.3(mole fraction), and the initial aqueous p H in a range of 1.00–4.00. Firstly, the extracted species were determined by the saturation extraction capacity method. Secondly, according to the equilibrium aqueous pH values, the extraction processes were divided into three different categories: extraction with saponified EHEHPA, extraction with un-saponified EHEHPA, and hydrolysis process. Finally, for the first two processes, in order to predict the distribution ratio, two semi-empirical calculation models were developed with.The calculation results are in good agreement well with the experimental data.  相似文献   

6.
A new kind of hydrophobic ionic liquids [1-alkyl-3-(1-carboxylpropyl)im][PF6] has been synthesized,and their extraction properties for Y(III) in the nitric acid medium was also investigated.The effects of extractant concentration,equilibrium pH of aqueous phase,salt concentration,temperature etc.were discussed.The results show that this kind of Task-Specific Ionic Liquid(TSIL) needs to be saponified before being used for the Y(III) ex-traction,and the extraction is acid dependent,and the extraction efficiency increases with the aqueous phase acidity decreasing.Furthermore,the loaded organic phase is easy to be stripped;more than 95% Y(III) could be stripped from the loaded organic phase when the stripping acidity is higher than 0.07 mol?L?1.The slope analysis technique is used to investigate the extraction mechanism,and a possible cation-exchange extraction mechanism is proposed in the present extraction system.  相似文献   

7.
In the extraction method for preparing KH2PO4, one of the key processes is the selective extraction of HCl over H3PO4. In our work, extraction kinetic studies have been carried out in a microfluidic device with a coaxial microchannel, using the extractant of 33.3%(by volume) trioctylamine (TOA) dissolved in n-octanol, with differ-ent aqueous phases:the HCl solution, the H3PO4 solution, and H3PO4 and KCl solutions of different concentra-tions. The changes of the extraction efficiency of HCl and H3PO4 and the selectivity for HCl along with the residence time were investigated. We found that fast extraction kinetics could be realized in microfluidic devices, and that HCl could be extracted faster than H3PO4 due to smaller mass transfer resistance and much stronger re-action between HCl and TOA. For the extraction of H3PO4 and KCl solutions, the selectivity for HCl first increased and then decreased when TOA was in excess of H3PO4 in the initial feeds, and in contrast, always increased when H3PO4 was in excess of TOA in the initial feeds. The diverse changes of selectivity for HCl along with the residence time indicate that a dynamic control of selectivity in microfluidic devices may be important and accessible for im-proving the KH2PO4 conversion efficiency in extraction method.  相似文献   

8.
A novel extractant mixture, di-2-ethylhexyl phosphate (DEHPA) plus HX, was proposed and tested for recovering gallium from sulfate solution. It was found that the extraction capacity of DEPHA for gallium from sulfate solution could be enhanced significantly due to the synergistic effect of acidic extractant HX. Gallium extraction is negligible below pH 0 and highly sensitive to pH of aqueous phase in the range from 0 to 1, and satisfactory extraction can be gained at pH>1. More than 96% Ga extraction was obtained using 15% DEHPA plus 2% HX. Although Fe (Ⅲ) was found to be extracted preferentially to Ga (Ⅲ), effective extraction of Ga (Ⅲ) was possible by reducing ferric to the ferrous state prior to extraction. A loaded organic phase containing 0.48g. L-1 Ga could be produced from solution of 0.12g@L-1 Ga at A/O ratio of 4: 1 via three mixer-settler operation stages.Gallium was stripped quantitatively from the loaded organic phase with 1.5 mol@L-1 of sulfuric acid.  相似文献   

9.
Recovery of Copper from Leaching Solution of Copper Smelting Ash   总被引:2,自引:0,他引:2  
An efficient and reliable approach based on solvent extraction to selectively recover copper from leaching solution of Jinchuan copper smelting ash has been developed in this work. And the extraction isotherm of 50%(j) N902 with initial aqueous acidity of 19.6 g/L was determined at 25℃. The results show that the extractant, N902, has good selectivity to copper, and its saturated capacity of copper under the given conditions is over 23 g/L. The recovery rate of copper in the extraction is over 99%. And copper extraction equilibrium is reached in 90 s using 50% N902 with kerosene as the diluenting agent at an organic and aqueous volume phase ratio (O/A) of 1. Furthermore, over 99.5% of the loaded copper in the organic phase could be stripped by applying 196 g/L H2SO4 as the stripping agent.  相似文献   

10.
Removal of cadmium(Ⅱ) ions from dilute aqueous solutions by complexation–ultrafiltration using rotating disk membrane was investigated. Polyacrylic acid sodium(PAAS) was used as complexation agent, as key factors of complexation, pH and the mass ratio of PAAS to Cd~(2+)(P/M) were studied, and the optimum complexation–ultrafiltration conditions were obtained. The effects of rotating speed(n) on the stability of PAA–Cd complex was studied with two kinds of rotating disk, disk Ⅰ(without vane) and disk Ⅱ(with six rectangular vanes) at a certain range of rotating speed. Both of the rejection could reach 99.7% when n was lower than 2370 r·min~(-1) and 1320 r·min~(-1), for disk I and disk Ⅱ, respectively. However, when rotating speed exceeds a certain value,the critical rotating speed(n_c), the rejection of Cd(Ⅱ) decreases greatly. The distribution of form of cadmium on the membrane was established by the membrane partition model, and the critical shear rate(γ_c), the smallest shear rate at which the PAA–Cd complex begins to dissociate, was calculated based on the membrane partition model and mass balance. The critical shear rates(γ_c) of PAA–Cd complex were 5.9 × 10~4 s~(-1), 1.01 × 10~5 s~(-1),and 1.31 × 10~5 s~(-1) at pH = 5.0, 5.5, and 6.0, respectively. In addition, the regeneration of PAAS was achieved by shear induced dissociation and ultrafiltration.  相似文献   

11.
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.  相似文献   

12.
PEG-(NH_4)_2SO_4双水相萃取法提取壳聚糖酶的研究   总被引:1,自引:1,他引:0  
采用PEG-(NH4)2SO4双水相体系直接从Bacillussp.LS发酵液上清液中分离壳聚糖酶。研究了体系中PEG分子量、PEG质量分数、(NH4)2SO4质量分数、NaCl质量分数和pH值对壳聚糖酶分配系数及萃取率的影响。结果表明,室温下双水相萃取最佳条件为:PEG600 20%、(NH4)2SO420%、NaCl 0.1%、pH值6.0,在此条件下壳聚糖酶分配系数达5.91,萃取率达88.7%。  相似文献   

13.
建立聚乙二醇-2000(PEG)-(NH4)2SO4双水相体系萃取光度法测定亮绿(BG)的新方法。测定了PEG相中亮绿吸收光谱和荧光光谱,研究了溶液酸度、盐用量、PEG用量及共存物质对体系测定的影响。结果表明,在溶液酸度pH=6,PEG用量5.0 mL,硫酸铵加入量2.0 g、测定波长630 nm时,PEG相中BG有最大吸光度。线性回归方程Y=0.005 83+0.054 53X,相关系数R=0.999 3,线性范围为0.01~0.17μg/mL。方法具有快速、灵敏、简便的优点,用于天然水中BG测定结果较好。用加入不同类型表面活性剂和光谱方法初步探讨了PEG与BG的相互作用。  相似文献   

14.
《分离科学与技术》2012,47(4):507-515
Abstract

Extraction of vanadium(V) from acidic sulfate solutions by a mixture of tri-n-octylamine and tributylphosphate (used as modifier) dissolved in kerosene has been studied. The distribution coefficient of vanadium(V) increases with an increase in pH and vanadium(V) concentration. The presence of iron(III) in aqueous solution does not have any appreciable effect, while large amounts of sulfate ion depress the distribution coefficient. Uranium(VI) has a distribution different from vanadium(V). Based upon these results, a scheme for the separation of vanadium(V) from uranium leach liquors has been made and checked experimentally.  相似文献   

15.
双水相体系从碱性氰化液中萃取分离金研究   总被引:4,自引:0,他引:4       下载免费PDF全文
报道利用聚乙二醇(PEG)/硫酸钠(Na2SO4)双水相体系从碱性氰化液中萃取分离金。实验考察初始水相 pH值,PEG及 Na2SO4浓度等对 KAu(C)2萃取影响。结果表明:富硫酸钠相(下相)的 KAu(CN)。几乎全部转移到富 PEG相(上相),且与pH值无关。随PEG或Na2SO4浓度减小,金的分配系数减小。双水相萃取可能为金分离提供了一种新方法。  相似文献   

16.
探讨TPEG6000/(NH4)2SO4双水相直接提取烟草中的烟碱和茄尼醇。研究烟草在不同的提取时间、不同温度、不同pH值等条件下双水相体系对烟叶中烟碱和茄尼醇的提取率。研究发现,烟草的加入量0.8g,(NH4)2SO4的质量分数为16.7%,提取时间3h,提取温度40℃,pH为7时,烟碱的提取率为3.65%,茄尼醇的提取率为2.11%。  相似文献   

17.
PEG/(NH42SO4双水相萃取分离茶氨酸的研究   总被引:1,自引:0,他引:1  
王艳  彭奇均 《应用化工》2011,40(7):1186-1191,1208
采用聚乙二醇(PEG)/(NH4)2SO4双水相体系萃取分离生产茶多酚所得废液中的茶氨酸,考察了PEG分子量与含量、硫酸铵含量、pH、温度、加盐(KCl、KBr、KI)、茶氨酸含量对双水相及萃取分离茶氨酸的影响。结果表明,PEG/(NH4)2SO4双水相萃取分离茶氨酸的适宜条件是:PEG平均分子量为4 000,质量分数为10%,硫酸铵质量分数为15%,pH约为6,30℃。在此条件下,茶氨酸的分配系数K1=0.16,蛋白质的分配系数K2=0.28,糖类的分配系数K3=9.8,茶氨酸在下相的萃取率为89.5%,可以将茶多酚废液中的茶氨酸与糖类及其他有颜色的杂质分开。  相似文献   

18.
杨利民  吕金萍  冯妍 《化工进展》2014,33(8):1992-1996,2011
蒲公英中内含的黄酮类物质具有较高药用价值,用双水相萃取法提取植物中有效成分是新型提取高附加值生物质的有效方法。本文考察了PEG/(NH4)2SO4双水相体系萃取分离蒲公英总黄酮时聚乙二醇相对分子质量、PEG质量分数、(NH4)2SO4质量分数、温度、pH值5个因素对分配行为的影响,并通过正交实验优化了工艺条件。结果表明最佳双水相提取工艺条件为:(NH4)2SO4质量分数18%,PEG1000质量分数23%,pH值5.34,提取温度25℃,NaCl盐的存在与否对萃取影响很小,蒲公英中总黄酮的提取率可达5.47%。因此,使用双水相法提取蒲公英总黄酮是该类提取技术中一种更加绿色环保和高效的方法。  相似文献   

19.
双水相体系萃取木瓜蛋白酶的研究   总被引:2,自引:0,他引:2  
采用聚乙二醇(PEG)/(NH4)2SO4双水相体系对木瓜蛋白酶进行萃取分离,研究了PEG相对分子量、PEG质量分数、(NH4)2SO4质量分数和pH值对木瓜蛋白酶分配系数及酶活力回收率的影响.结果表明,最佳萃取条件为:PEG4000质量分数6%、(NH4)2SO4质量分数18%、pH值6.0,在此条件下,木瓜蛋白酶的...  相似文献   

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