Extraction of Co(II) from aqueous solution using emulsion liquid membrane

The extraction equilibrium of Co(II) from thiocyanate medium by CYANEX 923 (mixture of straight chain alkylated phosphine oxides) in cyclohexane was studied. The stoichiometry of the extraction reaction was postulated based on slope analysis method and the extraction constant Kex was calculated. The stripping percentage of Co(II) with sulphuric acid from the loaded CYANEX 923 was found to increase with the increase in acid concentration. The extraction of Co(II) from aqueous thiocyanate medium into emulsion liquid membrane using CYANEX 923 extractant was also studied. The influence of different parameters such as stirring speed, surfactant concentration, pH of the extractant phase, carrier concentration, internal phase stripping acid concentration, initial Co(II) concentration as well as temperature on the emulsion stability were investigated. The applicability of the emulsion liquid membrane (ELM) process using CYANEX 923 as extractant and SPAN 80 as surfactant for the removal and the concentration of Co(II) from thiocyanate solution was investigated. The results show that it is possible to recover 95% of cobalt in the inner phase after 10 min of contacting time with a concentration factor of 5.     

乳状液膜法提取青霉素G的研究

使用青霉素Ｇ钠盐纯品溶液,模拟考察了乳状液膜法分离青霉素的条件．着重研究了提取率与膜中载体类型、Ｓｐａｎ－８０用量的关系,优化出最佳提取条件,在最佳条件下青霉素的提取率可达９２％,浓缩比可达９．     

液膜法处理高氟废水研究

利用Ｎ２０５－Ｎ１９２３－煤油液膜体系，ＣａＣｌ２溶液作内相，对高氟废水的处理进行了研究。利用正交实验确定了影响最大的因素，并研究了各种因素对处理的影响。经３０ｍｉｎ处理，外相Ｆ＾－浓度可由０．５００ｇ／Ｌ降至０．０１０ｇ／Ｌ以下，可达到工业排放标准。     

乳化液膜法脱除乙二醇中H_2S的研究

采用乳化液膜法对含H2S的乙二醇溶液进行脱硫研究.膜相由膜溶剂煤油、表面活性剂、流动载体乙二胺、膜稳定剂液体石蜡组成;内相试剂为NaOH.考察了传质时间、表面活性剂的种类及浓度、流动载体浓度、内相NaOH浓度、膜溶剂与内相试剂之比、乳化液与外相溶液之比、乙二醇溶液的初始硫含量以及传质搅拌速率对H2S脱除率的影响.试验结果表明,乳化液膜法用于含硫乙二醇溶液的脱硫是可行的,H2S脱除率可达到98%以上.     

乳状液膜法从发酵液中提取青霉素的研究

研究了用乳状液膜法从发酵液中提取青霉素Ｇ时,石蜡用量、搅拌速率、载体用量、内相碳酸钠溶液浓度和表面活性剂用量对青霉素提取的影响,在最佳条件下提取率可达７６．５％,浓缩比为６．０。     

Extraction of germanium from acidic leach solutions by liquid membrane technique

 Precipitates from a zinc plant (CINKUR Co., Turkiye) electrolyte purification section consist an average of 1200 ppm germanium, 10% copper, 15% zinc, 2.5% cadmium, 0.2% cobalt, and 8% iron. The precipitate or "copper" cake has been leached with sulphuric acid, and thus acidic leach liquors are obtained. The application of emulsion liquid membrane technique to the extraction of germanium from the acidic leach liquors is examined. The important variables governing the permeation of germanium through liquid membranes and their effects on the separation process are studied. These variables are the membrane type and composition, surfactant type and composition, carrier composition, pH, and various additives or modifiers. The carrier or the extractant used is an alkylated hydroxyquinoline, Kelex 100 that is manufactured by Schering Berlin AG, Germany. Under the suitable conditions it is possible to selectively extract 95% of germanium from the acidic leach solutions, containing Cu, Zn, Cd, Co and Fe ions, using the carrier Kelex 100. The authors wish to express their sincere gratitude to Exxon Chemical Co., U.K. and Belgium, for supplying the surfactant ECA 4360J, the solvents STA90 NS and Escaid 110. Received: 25 September 1998 / Accepted: 15 November 1998     

支撑液膜法提取柠檬酸——膜配方的研究

采用了支撑液膜法从柠檬酸的发酵液中提取柠檬酸,考察了膜的装配方法和载体浓度对传递通量及体系稳定性的影响,在该体系和一定的操作条件下,确定了合适的支撑液膜体系为聚丙烯微孔膜为支撑体,煤油为溶剂,TOA为载体,用湿法装配.     

乳状液膜法提取模拟湿法磷酸中的稀土镧

采用自制的磺化聚丁二烯(LYF)作表面活性剂,以二(2-乙基己基磷酸,P204)为萃取剂,以4mol/L HCl为内相,液体石蜡为膜稳定剂,制成乳状液膜,从模拟湿法磷酸中萃取稀土镧.在膜内比为1.2∶1,制乳搅拌,搅拌速度为2 000r/min,时间为20min,提取搅拌速度为250r/min,时间为10min,水乳体积比为2∶1,磷酸质量分数为10%P2O5,La3+含量为300mg/L时,镧离子的迁移率达到86.67%.同时利用液液萃取通过斜率分析法讨论P204从磷酸中提取镧离子的反应机理.对P204萃取镧离子进行热力学研究,结果表明,萃取反应属于放热反应,反应热为-7.697 1kJ/mol.     

Preparation of ferromagnetic microcapsules for hyperthermia using water/oil emulsion as a reaction field

Hyperthermia is a minimally invasive cancer treatment. As hyperthermia thermoseeds, ferromagnetic microcapsules of 20–30 μm in diameter have attracted much attention since their embolization effect cuts off the nutrition supply into cancer cells, ensuring that the microcapsules efficiently reach the tumor. In the present study, ferromagnetic microcapsules were prepared via iron hydroxide precipitation from a water/oil emulsion and subsequent hydrothermal treatment. The fundamental conditions for obtaining microcapsules of suitable size were investigated. The diameter of the obtained microcapsules tended to decrease as rotation speed increased during emulsion preparation or surfactant concentration in the oil phase. The sphericity of the microcapsules was improved at low surfactant concentration. A large amount of 20–30 μm-diameter magnetite microcapsules were obtained when the rotation speed and surfactant concentration were fixed at 1500 rpm and 0.35 mass%, respectively. The obtained microcapsules embedded in agar phantom exhibited heat generation under an alternating magnetic field.     

界面张力降低法设计液膜配方

研究了液膜体系各组分与油水界面张力降低的关系，提出了一种根据油水界面张力的降低，筛选表面活性剂、截体、助表面活性剂，和确定料液中待分离离子最佳浓度的方法。     

The role of some compounds on extraction of chromium(VI) by amine extractants

The extraction of hexavalent chromium, Cr(VI), from hydrochloric acid aqueous solution using Aliquat 336 and Alamine 336 extractants was performed under different experimental conditions. The data clarify that one molecule of amine extractants shares with approximately one molecule of HCl to extract two molecules of Cr(VI) from 1M HCl aqueous solutions. The extraction is an exothermic process and possesses enthalpy change values of -41.02 and -28.08 kJ mol(-1) for the extraction by Aliquat 336 and Alamine 336, respectively. The presence of potassium chloride greatly increases the extraction of Cr(VI) by amine extractants while the addition of some phenolic compounds such as phenol, dichlorophenol, o-nitrophenol and beta-naphthol decreases this extraction under the same experimental conditions.     

Separation and subsequent determination of low radioactivity levels of radium by extraction scintillation

A method is developed for separation and subsequent determination of low (226)Ra levels based on its extraction efficiency by various organic extractants followed by direct interaction with mixed scintillation cocktail (SC) in toluene as the most suitable solvent. Three organic extractants including Tricaprylmethyleammonium chloride (Aliquat-336), triphenylphosphine sulphide (TPPS) and tri-n-octylphosphine oxide (TOPO) are individually embedded in 1-phenyl,4-phenyloxazole (PPO) as a primary scintillator and 1,4-di-2-(4-methyl, 5-phenyl oxazoyl) benzene (POPOP) as a second scintillator. Different parameters affecting the extraction process including shaking time, type and concentration of extractant, aqueous/organic volume ratio as well as various levels of (226)Ra are individually investigated. Based on the optimized condition, it was found that the extraction of (226)Ra by Aliquat-336 is highly selective with efficient separation capability from (133)Ba, which is necessary to determine the yield and recovery of (226)Ra in related measurements. The combination of extraction with direct scintillation processes is mainly elaborated to overcome the heterogeneity problem and hence the slow scintillation rate that often exists in conventional liquid scintillation counting especially with low radioactivity levels.     

N263为载体的乳状液膜稳定性的研究

针对Ｎ２６３为载体的乳状液膜稳定性问题，研究了单一表面活性剂、混合表面活性剂、载体、膜相添加剂、外水相酸度及实验操作温度因素对液膜稳定性的影响。并探讨了表面活性剂Ｂ值与液膜稳定 之间的关系，从而得出一些影响乳状液膜稳定性规律的有效结论。     

Extraction kinetics of heavy metal-containing sludge

In order to remove and recover copper, zinc, cadmium, and chromium from the wastewater treatment sludge generated by an electroplating process, the heavy metal extraction kinetics was studied in a batch reactor using two different extraction agents (nitric and citric acid) at constant agitation speed (150 rpm) and solid to liquid ratio (10 g/L), but varying acid concentrations (0.02-0.10 N), temperatures (25-85 degrees C in nitric acid solution, 25-95 degrees C in citric acid solution), and sludge particle sizes. The shrinking-core model and empirical kinetic model were adopted to analyze the experimental data. Although both models could fit the experimental kinetic data well, the obtained parameters of the shrinking-core model did not show reasonable trends varying with the experimental variables while the empirical model parameters showed significant trends. The experimental and modeling results showed that the metal extraction rates increased with acid concentration, temperature, but decreased with increasing particle size. Nitric acid was found to be more effective than citric acid to extract the heavy metals from the sludge. The extraction activation energies obtained in this study suggested that both a physical diffusion process and a chemical reaction process might play important roles in the overall extraction process.     

乳状液膜法提取亮氨酸

研究了亮氨酸的乳状液膜提取方法．考察了外相溶液组成、内相 Ｈ＋ 浓度、外相ｐ Ｈ 值及载体用量对提取率的影响，从而确立了各影响因素的最佳值     

Electrochemical deposition of Ni–TiN nanocomposite coatings and the effect of sodium dodecyl sulphate surfactant on the coating properties

Ni–TiN nanocomposite coatings were prepared by using electrochemical deposition in a Watt’s bath containing TiN particles to increase the hardness of Ni. The effects of deposition current density, electrolyte agitation speed and the number of particles in the solution on the amount of incorporated particles in the coating process were investigated. The optimum deposition current density of 4 A dm^?2 and agitation speed of 450 rpm were obtained. The effect of sodium dodecyl sulphate (SDS) anionic surfactant on the amount of particles in the coatings was investigated. It was observed that the maximum amount of incorporated particles, with a value of 7.5% by volume, was created in the current density of 4 A dm^?2, stirring rate of 450 rpm, 30 g l^?1 TiN particles and in the presence of 0.6 g l^?1 SDS anionic surfactant.     

液膜常用表面活性剂对青霉素提取率及液膜溶胀的研究

采用以磷酸三丁酯(TBP)为流动载体,液体石蜡为膜相添加剂,煤油为膜溶剂与表面活性剂组成的W/O型乳状液膜体系提取模拟发酵液中的青霉素,考察了单一表面活性剂、混合表面活性剂对青霉素传质和液膜溶胀的影响.实验结果表明:聚胺类表面活性剂(兰113B、N205、ECA4360)对青霉素的提取率优于酯类表面活性剂(span80),且用量少、液膜溶胀率低;酯类表面活性剂与聚胺类表面活性剂不能配伍使用,聚胺类表面活性剂混合性能优于单一表面活性剂,有利于提高青霉素的传质,降低液膜溶胀.表面活性剂在液膜分离中起着极为重要的作用,直接影响着液膜的稳定性、溶胀性能及液膜的破乳.选择性能优良的表面活性剂,适宜的液膜配方和操作条件,有利于控制液膜溶胀,提高青霉素的提取率.     

Membrane optode for mercury(II) determination in aqueous samples

A color changeable optode for Hg(II) was prepared by the immobilization of a dye 4-(2-pyridylazo)resorcinol (PAR) and a liquid ion-exchanger trioctylmethylammonium chloride (Aliquat-336) in the tri-(2-ethylhexyl) phosphate plasticized cellulose triacetate matrix. Hg(II) and CH₃Hg⁺ from aqueous samples could be quantitatively preconcentrated in this transparent optode producing a distinct color change (λ_max = 520 nm) within 5 min equilibration time in bicarbonate aqueous medium or 30 min in natural water. Whereas optode sample without Aliquat-336 did not change its color corresponding to Hg–PAR complex on equilibrium with the same aqueous solution containing Hg(II) ions. The uptake of Hg(II) was found to be pH dependant with a maximum (>90%) at a pH 7.5. The uptake of ions like Cu(II), Fe(II), Zn(II) and Pb(II) was negligible in the optode where as the uptake of Cd(II) and Zn(II) ions was 10–15% at pH 7.5. The optode developed in the present work was studied for its analytical application for Hg(II) in the aqueous samples by spectrophotometry, radiotracer (²⁰³Hg), Energy Dispersive X-ray Fluorescence (EDXRF) analyses and Instrumental Neutron Activation Analysis (INAA). The minimum amount of Hg(II) required to produce detectable response by spectrophotometry, INAA and EDXRF were found to be 5.5, 1 and 12 μg, respectively. This optode showed a linear increase in the absorbance at λ_max = 520 nm over a concentration range of 0.22–1.32 μg/mL of Hg(II) ions in aqueous solution for 5 min. The preconcentration of Hg(II) from large volume of aqueous solution was used to extend the lower limit of concentration range that can be quantified by the spectrophotometry of optode. It was observed that preconcentration of 11 μg Hg(II) in 100 mL (0.11 μg/mL) in aqueous samples gives a distinct color change and absorbance above 3σ of the blank absorbance. The optode developed in the present work was found to be reusable.     

Removal of chromium (VI) ions from aqueous solution by adsorption onto two marine isolates of Yarrowia lipolytica

The removal of chromium (VI) ions from aqueous solutions by the biomass of two marine strains of Yarrowia lipolytica (NCIM 3589 and 3590) was studied with respect to pH, temperature, biomass, sea salt concentration, agitation speed, contact time and initial concentration of chromium (VI) ions. Maximum biosorption was observed at pH 1.0 and at a temperature of 35 °C. Increase in biomass and sea salts resulted in a decreased metal uptake. With an agitation speed of 130 rpm, equilibrium was attained within 2 h. Under optimum conditions, biosorption was enhanced with increasing concentrations of Cr (VI) ions. NCIM 3589 and 3590 displayed a specific uptake of Cr (VI) ions of 63.73 ± 1.3 mg g⁻¹ at a concentration of 950 ppm and 46.09 ± 0.23 mg g⁻¹ at 955 ppm, respectively. Scatchard plot analysis revealed a straight line allowing the data to be fitted in the Langmuir model. The adsorption data obtained also fitted well to the Freundlich isotherm. The surface sequestration of Cr (VI) by Y. lipolytica was investigated with a scanning electron microscope equipped with an energy dispersive spectrometer (SEM-EDS) as well as with ED-X-ray fluorescence (ED-XRF). Fourier transform infrared (FTIR) spectroscopy revealed the involvement of carboxyl, hydroxyl and amide groups on the cell surfaces in chromium binding.     

Removal of dyes and their mixtures from aqueous solution using liquid emulsion membrane

Extraction of dyes from aqueous solution was studied using liquid emulsion membrane. Study was carried out using two dyes, namely, crystal violet (CV) and methylene blue (MB). Extraction of single component system of each dye and their binary mixture were investigated. Liquid emulsion membrane was formed using n-heptane as membrane phase, sodium hydroxide solution as the internal phase and dye solution as the external phase. Surfactant span 80 was used as the emulsion stabilizer. Effects of concentration of span 80, concentration of NaOH, stirring speed, composition of feed solution and the volume ratio of the oil phase to the aqueous phase (O/A) were studied in detail both for single and binary system. Maximum extraction of MB was found to be 99% and that for CV was about 95% in single component system. In binary mixture, these values were 97% and 90%, respectively.