• 한국산학기술학회논문지
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• 제3권2호
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• pp.141-145
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• 2002

이온교환수지탑으로 유입된 이온은 연속적인 이온교환 평형을 이루면서 수지층을 통과한다는 가정하에 질량작용법칙과 몰 균형식을 조합하여 연속이은교환평형 칼럼모델을 개발하였다. 연속이온교환평형 칼럼모델을 이용하여 원자력발전소 복수탈염설비 탈염기의 성능을 평가한 결과, Na/sup +/및 Cl/sup -/누출 농도는 수지의 재생효율에 따라 다르며, 특정이온의 유입수 및 유출수에서 농도 비율은 용액 및 수지의 상태에 따라 달라짐을 확인하였다. 본 모델은 수지농도를 보정하여 국부 불완전 평형을 고려할 수 있고, 다성분 존재하의 경쟁적 이온교환을 묘사할 수 있는 장점을 가지고 있다.

• 한국산학기술학회논문지
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• 제3권3호
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• pp.194-197
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• 2002

이온교환은 액체상 이온과 고체상 이온간의 화학반응이며 연수 및 탈염공정, 특정물질의 제거 및 회수, 토양을 통한 이온성 물질의 이동에서 널리 이용되고 있다. 이온 선택도는 원자가가 높을수록, 수화반경이 작을수록 증가한다. 본 연구는 평형 이온교환에서 결정된 이온 선택도가 칼럼 이온교환에 적용되는 가를 조사하였다. 음이온 교환수지에 대한 이온 선택도 순서는 OH/sup -/ < F/sup -/ < HCO/sup -/ < Cl/sup -/ < Br/sup -/ ≤ NO₃/sup -/ < SO₄/sup 2-/ 이였으며, 음이온 칼럼교환에서도 동일하였다. 또한 바탕 양이온의 전하가 낮을수록 이온교환이 빠르게 진행됨을 알 수 있었다.

• 한국환경과학회지
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• 제7권1호
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• pp.89-95
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• 1998

Ion exchange performance to remove nitrate in water was studied using commercially available strong base anion exchange resin of Cl- type in the batch and continuous column reactors. The performance was tested using the effluent concentration histories for continuous column or equilibrium conquilibrium between resin and solution. Anion exchange resin used in this study was more effective than activated carbon or zeolite for nitrate removal. With large resin amount or low initial concentration, nitrate removal characteristics for a typical gel-type resin was Increased. On considering the relation between the breakthrough capacity and nitrate concentration of the influent, the use of anion exchange resin were suitable for the hi선or order water treatment. The nitrate removal of above 90% could be possible until the effluent of above 650 BV was passed to the column. Thus, the commercially available strong base anion exchange resin of $Cl^-$ type used in thins study could be effectively used as economic material for treatment of the groundwater. The breakthrough curves showed the sequence of resin selectivity as $SO_4^{2-}$ > $NO_3$ > $NO^{2-}$ > $HCO_3^-$. The results of this study could be scaled up and used as a design tool for the water purification system of the real groundwater and surface water treatment processes.

• FOCUS: LIFE SCIENCE
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• 제1호
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• pp.5.1-5.3
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• 2024

The document discusses the regeneration of Partisil/Partisphere ion-exchange columns in chromatography. It mentions that column efficiency can diminish with use due to the accumulation of sample and/or mobile phase impurities at the head of the column. This can lead to a change in back pressure, lower column efficiency, and sometimes a change in selectivity. The document outlines a procedure that may restore column performance. The document also provides everyday practices to enhance the lifetime of a column. These include using only high-purity HPLC solvents and buffers, using freshly prepared mobile phases and buffers, filtering mobile phases to remove particulates, using appropriate sample clean-up procedures, using a guard column or pre-column filter, and working within the pressure and flow rate limitations of the column. For the regeneration of Partisil/Partisphere SAX, SCX, WAX, and WCX columns, the document suggests passing 20 column volumes of various mobile phases through the column. These include a buffer wash, distilled water, an acid wash, a chelating wash, a methanol wash, and a buffer for separation. The document emphasizes that not all of these wash steps are required for every column clean-up and that some chromatographers require only a combination of certain steps.

• 한국물환경학회지
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• 제29권6호
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• pp.777-781
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• 2013

Ion-exchange technology is one of the best for removing nitrate from drinking water. However, problems related to the disposal of spent brine from regeneration of exhausted resins must be overcome so that ion exchange can be applied more widely and economically, especially in small communities. In this background, a combined bio-regeneration and ion-exchange system was operated in order to prove that nitrate-laden resins could be bio-regenerated through direct contact with denitrifying bacteria. A nitrate-selective A520E resin was successfully regenerated by denitrifying bacteria. The bio-regeneration efficiency of nitrate-laden resins increased with the amount of flow passed through the ion-exchange column. When the fully exhausted resin was bio-regenerated for 5 days at the flowrate of 30 BV/hr and MLSS concentration of $125{\pm}25mg/L$, 97.5% of ion-exchange capacity was recovered. Measurement of nitrate concentrations in the column effluents also revealed that less than 5% of nitrate was eluted from the resin during 5 days of bio-regeneration. This result indicates that the main mechanism of bio-regeneration is the direct reduction of nitrate by denitrifying bacteria on the resin.

• Macromolecular Research
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• 제13권1호
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• pp.39-44
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• 2005

Ion-exchange polymeric stationary phases presenting amino acid and amino groups were prepared by the surface grafting of glycidyl methacrylate onto a silica gel surface and subsequent amination. Three kinds of amino acids-L-arginine (Arg), D-lysine (Lys), and D-histine (His)-were used in this study. An ion-exchange polymeric stationary phase presenting ethylene diamine (EDA) was also prepared by surface graft polymerization. Separation of the model proteins bovine serum albumin (BSA), chick egg albumin (CEA), and hemoglobin (Hb) was performed using the amino acid- and amine-derived columns. In separating the CEA/BSA mixture, the resolution time of BSA was longer than that of CEA when using the EDA column, whereas the resolution time of BSA was shorter than that of CEA when using the Arg, Lys, and His columns. In the separation of the Hb/BSA mixture, the resolution time of BSA was longer than that of Hb in the EDA column, whereas the resolution time of BSA was shorter than that of Hb in the amino acid columns (D-Lys, L-Arg, and D-His).

• Biotechnology and Bioprocess Engineering:BBE
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• 제2권2호
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• pp.117-121
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• 1997

Glutamic acid can be crystallized inside cation exchange column when displacer NaOH concentration is high enough to concentrate displaced glutamic acid beyond its solubility limit. Resulting crystal layer of glutamic acid was moved with liquid phase through the column, and thus could be eluted from the column and recovered in fraction collector. For the purpose of enhancing crystal recovery, effects of operating parameters on the crystal formation were investigated. The increase in the degree of crosslinking of resin favored crystal recovery because of its low degree of swelling. Higher concentration of displacer NaOH was advantageous. If NaOH concentration is too high, however, crystal recovery was lowered due to the solubility-enhancing effects of high pH and ionic strength. The decrease of mobile phase flow rate enhanced crystal recovery because enough time to attain local equilibrium could be provided, but film diffusion would control the overall crystal formation with extremely low flow rate. Lower temperature reduced solubility of glutamic acid and thus favored crystal formation unless the rate of ion exchange was severely reduced. The ion exchange operated by displacement mode coupled with crystallization was advantageous in reducing the burden of further purification steps and in preventing purity-loss resulted from overlapping between adjacent bands.

• 환경위생공학
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• 제23권1호
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• pp.67-72
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• 2008

Ion exchange performance to remove Ammonium in water was studied using commercially available strong acidic cationic exchange resin of $Na^+$ type in the batch and continuous column reactors. The performance was tested using the effluent concentration histories for continuous column or equilibrium concentrations for batch reactor as a function of time until resins were exhausted or reached ionic equilibrium between resin and solution. The results shoed that cationic exchange resin used in this study was more effective than activated carbon or zeolite for ammonium removal. Ammonium removal with the ion exchange resin temperature to be high qualitative recording minuteness but increases about seasonal change of temperature was judged with the public law where the adaptability is excellent. When the pH comes to be high at 11 degree, the ammonium was not effectively removed.

• 한국식품과학회지
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• 제24권6호
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• pp.616-618
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• 1992

본 연구에서는 효과적으로 이용하지 못하는 굴박신액에서 이온교환 크로마토그라피로 taurine의 분리하고자 하였다. Dowex 50W $H^+$형과 Dowex 2 OH 형으로 처리한 용출액 중 흡광도가 높게 나타난 획분을 Amberite IRA-410 $OH^-$형에 다시 용출시켜 taurine을 흡착시킨 후 흡착한 taurine을 0.1M acetic acid로 용출시키면 수율과 순도가 84.8%와 94.9%인 taurine을 얻을 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제17권9호
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• pp.1527-1532
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• 2007

Lysine produced during microbial fermentation is usually recovered by an ion-exchange process, in which lysine is first converted to the cationic form (by lowering the pH to less than 2.0 with sulfuric acid) and then fed to a cationexchange column containing an exchanger that has a sulfone group with a weak counterion such as NH;. Ammonia water with a pH above 11 is then supplied to the column to displace the purified lysine from the column and allow its recovery. To enhance the adsorption capacity and for a possible reduction in chemical consumption, monovalent lysine fed at pH 4 was investigated in comparison with conventional divalent lysine fed at pH 1.5. The adsorption capacity increased by more than 70% on a mass basis using pH 4 feeding compared with pH 1.5 feeding. Lysine adsorbed at pH 4 started to elute earlier than that adsorbed at pH 1.5 when ammonia water was used as the eluant solution, and the extent of early elution became more notable at lower concentrations of ammonia. Moreover, the elution of monovalent lysine fed at pH 4 displayed a stiffer front boundary and higher peak concentration. However, when the ammonium concentration was greater than 2.0 N, complete saturation of the bed was delayed during adsorption and the percent recovery yield from elution was lowered., both drawbacks that were considered inevitable features originating from the increased adsorption of monovalent lysine.