• Resources Recycling
• /
• v.25 no.1
• /
• pp.16-23
• /
• 2016

The separation behaviour of Mo and W from sulfuric acid solution by solvent extraction with Alamine 336 was investigated as a function of solution pH and extractant concentration. Selective extraction of Mo over W by Alamine 336 was obtained in the pH range of 3-5 with low amine concentration. The mixture of Alamine 336 and acidic extractants improved the separation factor between Mo and W and was in the following order: D2EPHA > PC88A > Decanol > Versatic acid. The stripping efficiency of Mo and W from the loaded mixture of Alamine 336 and D2EHPA was very poor, while complete stripping of Mo and W was possible from the mixture of Alamine 336 and Decanol by using a mixture of $NH_4OH$ and $NH_4Cl$.

• Membrane and Water Treatment
• /
• v.7 no.6
• /
• pp.521-537
• /
• 2016

Laboratory-scale experiments were carried out to investigate the adsorption equilibrium, the adsorption kinetics and facilitated transport of two cationic dyes (Methylene Blue (MB) and Rhodamine B (RB)) on Polymer Inclusion Membrane (D2EHPA-PIM). Different adsorption isotherms (Freundlich, Langmuir and Temkin models) as well as kinetics models indicated that the adsorption process is spontaneous and exothermic. Under the optimal conditions, the adsorption removal efficiencies reach about 93% and 97% for MB and RB respectively. Different extraction values by D2EHPA-PIM were obtained for the two cationic dyes: MB is weakly extracted at pH 2.0 (E% = 18.7%) whilst E% = 82.4% was observed for RB at the same pH. This difference was exploited in a mixture containg both the 2 cationic dyes for the selective extraction of RB at pH 2. Desorption of both dyes was achieved from the membrane by using acidic aqueous solutions and desorption ratio up to 90% was obtained. The formulas of the extracted complexes by the PIMs were, determined by the method of slopes. The dyes transport was elucidated using mass transfer analysis where in it found relatively high values of the initial flux ($J_0$) as 41.57 and $18.74{\mu}mol.m^2.s^{-1}$ for MB and RB respectively.

• Resources Recycling
• /
• v.33 no.1
• /
• pp.31-36
• /
• 2024

The separation of Ag and Zn from the nitrate leachate of spent silver oxide batteries using Cyanex272 as an extractant was investigated. The extraction of Ag and Zn was affected by the concentrations of nitric acid and the extractant. Cyanex-272 selectively extracted Zn over Ag when the HNO₃ concentration was lower than 0.1 mol/L. The co-extracted Ag was removed by stripping with 1 mol/L thiourea. Stripping of Zn from the loaded Cyanex-272 was accomplished using 0.5 mol/L HNO₃ after the removal of Ag. The McCabe-Thiele diagrams for the extraction of Zn with Cyanex-272, the scrubbing tripping of Ag with thiourea, and the stripping of Zn with HNO₃ were constructed. The results were verified by simulated counter-current extraction and stripping experiments. Finally, a process for the separation of Ag and Zn from silver oxide batteries was proposed.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1996.03a
• /
• pp.69-90
• /
• 1996

In the chemical industry, in the pharmaceutical industry, and in a number of other industries separation processes are necessary to separate and purify products and raw materials [1,2]. Separation processes are also widely used in other applications such as in recycling valuable materials from waste streams. Unit operations for separation processes can be classified in phase separation techniques and component separation techniques based on the nature of the feed mixtures to be separated. The former techniques are used for the separation of heterogeneous mixtures, in which the feed is already present in two or more separated phases on a micro-scale. The latter are suitable for the separation of homogeneous mixtures such as gaseous mixtures and mixtures of completely miscible liquids. tn these cases the separation into individual components is generally achieved by utilizing the differences in physico-chemical properties of components, and is much more difficult compared to phase separation techniques. Separation processes such as distillation, evaporation, liquid-liquid extraction, and crystallization belong to this class.

• KSBB Journal
• /
• v.27 no.3
• /
• pp.177-185
• /
• 2012

Inonotus obliquus mushroom, which is a fungus belonging to Hymenochaetaceae family, is known to grow on birth trees in colder northern climates and to be a fungal parasite that draws nutrients out of living trees rather than from the ground. For the separation of protein-bound polysaccharide (PBP) from the culture broth and mycelium of Inonotus obliquus, three well known extraction methods namely hot water, ultrasound and microwave were used. The best extraction conditions to separate the PBP (64.94 mg/g) from mycelium by microwave were found to be for 1 hour and $150^{\circ}C$. The possibility for concentration of extracted PBP solution by using membrane was also studied. The extracted PBP solution was concentrated effectively by using an ultrafiltration membrane and the molecular weight cut off (MWCO) is 30 KDa. It was observed that a concentration by the ultrafiltration membrane is essential not only for the development of clean separation technology but also for enhanced production of PBP. As a result, we have shown that PBP in the final concentrated solution showed approximately 10 times higher than that in the crude solution by application of the developed separation systems. The separation yield of PBP was about 89.79% by gel filtration of purification steps and the purified product was confirmed to be PBP by using FT-IR.

• Analytical Science and Technology
• /
• v.37 no.2
• /
• pp.123-129
• /
• 2024

We present a rapid method for the determination of Cs, Sr, and Ba, heat generators found in highly active liquid wastes, by gas-pressurized extraction chromatography (GPEC) using a column containing a cation-exchange resin. GPEC is a microscale column chromatographic technique that uses a constant flow rate of solvent (0.07 mL/min) with pressurized nitrogen gas supplied through a valve. In particular, because this method uses a small sample volume (a few hundred microliters), it produces less chemical waste and allows for faster separation compared to traditional column chromatography. In this study, we evaluated the separation of Cs, Sr, and Ba using GPEC. The eluate from the column (GPEC or conventional column chromatography) was quantitatively analyzed using inductively coupled plasma-mass spectrometry to measure the column recovery and precision. The column reproducibility of the proposed GPEC system (RSDs of recoveries) ranged from 2.7 to 4.1 %, and the column recoveries for the three elements ranged from 72 to 98% when aqueous HCl was used as the eluent. The GPEC results are slightly different in efficiency and separation resolution compared to those of conventional column chromatography because of the differences in the eluent flow rate as well as the internal diameter and length of the column. However, the two methods had similar recoveries for Cs and Sr, and the precision of GPEC was improved by two-fold. Remarkably, the solvent volume required for GPEC analysis was five times lower than that of the conventional method, and the total analysis time was 11 times shorter.

• Resources Recycling
• /
• v.26 no.4
• /
• pp.79-87
• /
• 2017

Extraction and separation behaviors of La, Ce, Pr, Nd and Sm from light rare earth multi - component mixed solutions by Cyanex 572 were studied. As extractant concentration increased, the $pH_{50}$ values of all the five components decreased. When extractant concentration was larger than 0.6 M, the separation factor of La and Ce, Nd and Sm was higher than 10, while the separation factor between Ce and Pr, Pr and Nd was as low as 0.5~2.2. Addition of TBP to the 0.6 M Cyanex 572 had little synergistic effect on the phase separation rate and separation factor. From the analysis of experiment results, group separation of [La]/[Pr, Nd, Sm] and [Pr, Nd]/[Sm] could be possible, but in case of the group separation between [La, Ce] and [Pr, Nd] was not available because of the low separation factor between Ce and Pr.

• Clean Technology
• /
• v.14 no.4
• /
• pp.275-280
• /
• 2008

In this study, we carry out economic and technical feasibility study for treatment process of waste solvent such as SD waste solution and stripper solution from LCD manufacturing process. Extensive screening work has been done for selecting the best extraction solvent. As a result, it is shown that $CHCl_3$ is the most adequate extraction solvent for separation and recovery of both SD waste solvent and stripper waste. Rigorous simulation study has been carried out for extraction process and distillation process as a candidate of waste solvent treatment. The result shows that the solvent extraction process is more beneficial than the simple distillation process.

• KSBB Journal
• /
• v.18 no.5
• /
• pp.408-411
• /
• 2003

By reversed-phase high-performance liquid chromatography, the extraction and separation of glabridin by from licoricce root was performed in this work. The column efficiencies and resolutions of glabridin were investigated with mobile phase composition on the reversed-phase chromatographic system. The glabridin collected from licorice root was identified by LC/MS. The mobile phase used to extract glabridin were composed of ethanol, methanol, acetone, and ethyl acetate. For one-hour ultrasonic extraction with solvent of ethyl acetate, the favorable content of glabridin was obtained as 1.26g/kg. The glabridin was well separated in the mobile phase composition of 50/50 vol. % (acetonitrile/water).

• Journal of applied mathematics & informatics
• /
• v.26 no.5_6
• /
• pp.1149-1159
• /
• 2008

Blind source extraction (BSE) is a special class of blind source separation (BSS) methods, which only extracts one or a subset of the sources at a time. Based on the time delay of the desired signal, a simple but important extraction algorithm (simplified " BC algorithm")was presented by Barros and Cichocki. However, the performance of this method is not satisfying in some cases for which it only carries out the constrained minimization of the mean squared error. To overcome these drawbacks, ICA with reference (ICA-R) based approach, which considers the higher-order statistics of sources, is added as the second stage for further source extraction. Specifically, BC algorithm is exploited to roughly extract the desired signal. Then the extracted signal in the first stage, as the reference signal of ICA-R method, is further used to extract the desired sources as cleanly as possible. Simulations on synthetic data and real-world data show its validity and usefulness.