• Biotechnology and Bioprocess Engineering:BBE
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• v.2 no.2
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• pp.97-100
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• 1997

Cyclodxtrin homologues(CDs), produced by cyclodextrin glycosyltransferase(CGTase), were simultaneously partitioned in aqueous two-phase system(ATPS). Partition coefficients of CDs were measured in PEG/dextran systems. Phosphate, citrate, sulfate were tested as salt. ATPS of PEG/salt and PEG/dextran had the partition coefficients of the CDs, larger than unity. However, PEG/dextran system was observed better than PEG/salt as CGTase activity decreased sharply with salt concentration. Enzymatic rection occurred mainly in PEG-rich bottom phase because of the low partition coefficient of CGTase. The resulting CDs transferred to the PEG-rich top phase, obeying the diffusional partition. In the ATPS of 7% PEG(M.W.40, 000), 7mg/ml of CDs were obtained in top phase at 4.5 hours.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.6
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• pp.395-401
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• 2001

Crystallins are a family of water-soluble proteins that constitute up to 90% of the wa-ter-soluble proteins in mammalian eye lenses, We present in this paper an alternative purification method for these proteins using polyethylene glycol/dextran aqueous two-phase extraction. Un-der the appropriate conditions, we were able to recover the γ-crystallin fraction essentially free of the remaining proteins. High concentrations of salt at a neutral pH maximize the recovery of γ-crystallins in the top phase and minimize the contamination by the other proteins present in the lenses. The proposed protocol decreases the separation time by about 50%. The complex partition behavior observed for these proteins reflects a delicate balance between protein/phase-forming species(various polymers and salts) and protein interactions. This is evidenced, in part, by the role played by the largest proteins in this group as a "pseudo"phase-forming species.

• Korean Journal of Materials Research
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• v.34 no.5
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• pp.247-253
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• 2024

The separation of zirconium and hafnium using tributyl phosphate (TBP)-Dodecane extractants in nitric acid medium was performed. Zirconium oxychloride, used as extraction feed, was obtained from the synthesis of Kalimantan zircon sand concentrate smelted using NaOH. The extraction process was carried out by dissolving chloride-based metals in nitric acid media in the presence of sodium nitrate using TBP-Dodecane as an extractant. Some of the extraction parameters carried out in this study include variations in organic phase and aqueous phase (O/A), variations in contact time, and variations in nitric acid concentration. Extraction was carried out using a mechanical shaker according to the parameter conditions. X-ray fluorescence (XRF) was used for elemental (Zr and Hf) composition analysis of the aqueous solution. The results showed that zirconium was separated from hafnium at optimum conditions with an organic/aqueous ratio of 1:5, contact time of 75 min, and an HNO₃ concentration of 7 M. The resulting separation factor of zirconium and hafnium using TBP-Dodecane was 14.4887.

• Fibers and Polymers
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• v.4 no.1
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• pp.27-31
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• 2003

A major concern in solvent extraction process is the loss of extractant into the aqueous phase due to its slight solubility in the aqueous phase. Similarly, in membrane extraction processes, extractant loss through extractant leakage from the membrane into the aqueous phase is also a concern. Several published membrane extraction studies using Aliquat 336 ai the extractant, have expressed this concern, but none has studied extractant leakage quantitatively. It is the authors' opinion that the extractant leakage should be considered at a technical parameter of a membrane. In our laboratory active progress has been made in using Aliquat 336 ‘entangled’ into the polymer membranes to remove heavy metal ions from wastewater samples. In this work, we studied the loss of Aliquat 336 from the point of view of its solubility in aqueous solutions. The results showed that the solubilities or Aliquat 3,36 in an aqueous phase acidified with 2 M HCI it about 0.1 g/100 m/ of the solution. This figure provides a useful guideline for evaluating the leakage of the Aliquatoat 336 extractant from the membranes.

• Korean Chemical Engineering Research
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• v.43 no.3
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• pp.380-386
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• 2005

Separation of fructose and glucose was performed using emulsion liquid membranes with a mixture of an organoboronic acid and a quaternary ammonium salt as a carrier in a batch reactor. In order to find a carrier and an optimal experimental condition suitable to the sugar separation, extraction of each sugar was carried out independently. The effect of various experimental variables, such as initial concentration of sugar in the feed phase, type of organoboronic acids, and w/o ratio, on the sugar separation was investigated, and the concentrations of sugars in each aqueous phase were analyzed. The ratio of degree of extraction of fructose to that of glucose was very high, but the concentration of fructose in the receiving phase was not too high. Therefore, a stronger stripping agent in the receiving phase was required for development of a practical ELM system suitable to the sugar separation.

• Proceedings of the Membrane Society of Korea Conference
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• 1991.10a
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• pp.1-3
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• 1991

A novel membrane separation process for the separation of liquid mixture is Pervaporation. The term, 'pervaporation', is a combination of permeation and evaporation, and was first introduced by kober[1] in 1917. In this technique, the liquid mixture in feed is in contact with one side of a dense non-porous membrane and after diffusing through the membrane is removed from the downstream side in the vapor phase, but is usually condensed afterwards to obtain a permeate in liquid from.

• Korean Chemical Engineering Research
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• v.54 no.1
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• pp.52-56
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• 2016

As an effective method for extraction of succinic acid, aqueous two-phase systems based on piperidinium ionic liquids were used in this study. Effects of the alkyl chain length of cation in piperinidium ionic liquids on phase diagram and extraction efficiencies were investigated. Experimental results show that aqueous two phase systems can be formed by adding appropriate amount of piperidinium ionic liquids to aqueous $K_2HPO_4$ solutions. It can be found that the ability of piperidinium ionic liquids for phase separation followed the order [OMPip][Br]>[HMPip][Br]>[BMPip][Br]>[EMPip][Br]. The biphase-forming ability of piperidinium ionic liquids was higher than that of imidazolium and pyrrolidinium ionic liquids in the presence of $K_2HPO_4$. 75~95% of the succinic acid could be extracted into the ionic liquid-rich phase in a single-step extraction. There was little difference in the extraction efficiency of succinic acid by piperidinium ionic liquids comparing to other ionic liquids such as imidazolium and pyrrolonidium ionic liquids. This aqueous two phase system by piperidinium ionic liquid is suggested to have effective application for the separation of succinic acid.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.618-623
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• 2003

Solvent extraction experiments for separation of impurities from Ni-rich solution were carried out for manufacturing of high purity Ni compounds from acid leaching solution of spent Ni-Cd secondary battery. Artificial and leaching solutions were used as aqueous phases and PC88A saponified by sodium in kerosene were used as organic phase. The extraction order is Zn>Mn>Co>Ni and extraction percentage of metal ions was increased with increase of the concentration of extractant, initial pH of aqueous phase and ratio of O/A. The separation of cobalt, zinc and manganese from nickel was effectively accomplished at the condition of extraction stage=l, O/A=1 and initial pH 5.0 with 1.0 $mol/dm^3$ PC88A saponified to $50\%$ with NaOH.

• Clean Technology
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• v.20 no.4
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• pp.349-353
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• 2014

Succinic acid is an important precursor in industries producing biopolymers, pharmaceutical and food additives and green solvents. However, due to the high price of petroleum and the global $CO_2$ emission, the biological production of succinic acid from renewable biomass is a novel process due to the fixation of $CO_2$ into succinate during fermentation. In this study, aqueous two phase systems based on imidazolium ionic liquids/$K_2HPO_4$ were used as an effective separation and concentration process for succinic acid. Experimental results show that aqueous two phase systems can be formed by adding appropriate amount of imidazolium ionic liquids to aqueous $K_2HPO_4$ solutions in the presence of succinic acid. It can be found that the ability of imidazolium ionic liquids for phase separation followed the order [HMIm][Br]${\fallingdotseq}$[OMIm][Br]>[BMIm][Br]>[EMIm][Br]. The maximum value of extraction efficiency for succinic acid was about 90% and the amount of coextracted water into top phase is proportional to the chain length of cation in imidazolium ionic liquids. It was concluded that the aqueous two phase systems composed of imidazolium ionic liquids/$K_2HPO_4$ was effective for the selective extraction and concentration of succinic acid.

• Resources Recycling
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• v.14 no.6 s.68
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• pp.10-15
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• 2005

In this study, the separation of samarium to neodymium with Karr column was investigated. Separation properties of Sm/Nd binary system was estimated with experimental parameters such as flow rate, initial pH of aqueous phase, saponification of PC88A in organic phase and agitation speed. The extraction rate and distribution coefficient increased with increasing initial pH of aqueous phase at 16.5 ml/min(retention time 10 minute) of flow rate of organic and aqueous phase, and equilibrium pH of aqueous phase after extraction was maintained at 1.5 by saponified PC88A. Also, the extraction rate and distribution coefficient were drastically increased with increasing saponification degree of PC88A and agitation speed, and optimal saponification degree was $40\%$. Extraction rate of Nd and Sm was $19.6\%$ and $72.5\%$ respectively at retention time 10 minute, initial pH 1, saponification degree $40\%$ and agitation speed 120 rpm.