• Membrane and Water Treatment
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• 제1권1호
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• pp.39-47
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• 2010

Using a conventional two-compartment cell with stirrers the separation of an aqueous solution of HCl-$NiCl_2$ by an anion-exchange membrane Neosepta-AFN was investigated. The dialysis process was characterized by the permeability coefficient of the membrane towards to $Cl^-$ ions. This quantity was determined by the numerical integration of equations, which describe the time dependence of the total concentration of $Cl^-$ ions in compartment initially filled with stripping agent (water), combined with an optimizing procedure. The analysis of the experimental results showed that this permeability coefficient is a satisfactory characteristic for the process studied. It can be graphically correlated with the initial acid and initial salt concentrations in the compartment initially filled with acid+salt mixture.

• Journal of Radiation Protection and Research
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• 제26권3호
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• pp.191-195
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• 2001

An accurate and simple analytical technique for low levels of fallout Pu in the environment was developed using an anion exchange resin. To develop the reliable determination of Pu isotopes in soil samples, decomposition of soil matrix, plutonium oxidation state adjustment on the anion exchange column and source preparation of Pu isotopes have been carried out. The optimum method of Pu isotopes with an anion exchange has been validated by application to IAEA-Reference soils.

• Bulletin of the Korean Chemical Society
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• 제26권2호
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• pp.248-252
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• 2005

Synthetic layered double hydroxides (LDHs), [$Mg_4Al_2(OH)_{12}]CO_3{\cdot}nH_2O$, were prepared in the submicron size of plate-like polycrystals. Anion-exchange reactions with various linear dicarboxylic acids were performed to produce LDH/organic hybrid materials by solvothermal treatment in toluene. X-ray powder diffraction spectra for the products indicated that the interlayer spacings of LDHs remarkably changed, up to 20 $\AA$ when 1,10-decanedicarboxylic acid anions were intercalated as an organic guest. Dicarboxylates-LDHs samples could be also re-exchanged consecutively with other dicarboxylic acids or carbonate without serious destruction of layer structure under the scanning electron microscopic observation.

• 한국식물병리학회지
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• 제14권6호
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• pp.559-562
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• 1998

Odontoglossum ringspot virus (ORSV) was finally purified from ORSV-infected orchid plants by diethylaminoethyl (DEAE) cellulose anion exchange column chromatography. The virus was reliably eluted by potassium chloride at the concentration from 0.1 M to 0.13 M. Partial purification was done by solubilization with Triton X-100 (allkylphenoxypolyethoxy ethanol) and precipitation with polyethylene glycol (PEG; MW 8,000). The finally purified ORSV represented one distinct homogeneous band and the molecular weight of its capsid protein was about 17,500 Dalton in electrophoretic analysis. Electron microscopy showed not only intact particles ranged from 280 nm to 340 nm in length, but also segmented particles that final 140 nm to 220 nm and even disks. Enzyme-linked immunosorbent assay (ELISA) showed that final yield was 12 mg/100 g of the infected leaves. Bioassay demonstrated that the purified ORSV had the normal infectivity to orchid plants and Nicotiana glutionsa. Based on these data, anion exchange column chromatography could be efficiently applied to the purification of ORSV and other viruses similar to ORSV.

• 대한화학회지
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• 제24권3호
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• pp.239-244
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• 1980

모나자이트 중의 Y, La, Ce, Pr 및 Nd 들을 pH 8.4에서 EDTA와 착염을 만들어 미리 음이온 교환수지에 EDTA를 흡착시킨 수지관에 용리시켜 희토류 원소들의 분리를 시도하였다. 용리액은 pH 8.4의 EDTA를 사용하였으며, 용리액의 분율에 따라 측정한 각이온의 분리도는 55∼98%이었다.

• Journal of Electrochemical Science and Technology
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• 제12권3호
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• pp.358-364
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• 2021

In this study, an anion exchange membrane water electrolysis (AEMWE) cell was operated for ~1000 h at a voltage bias of 1.95 V. Impedance spectra were regularly measured every ~ 100 h, and changes in the ohmic and non-ohmic resistance were traced as a function of time. While there was relatively little change in the I-V curves and the total cell resistance during the long-term test, we observed various electrochemical phenomena in the cell: 1) initial activation with a decrease in both ohmic and non-ohmic resistance; 2) momentary and non-permanent bubble resistance (non-ohmic resistance) depending on the voltage bias, and 3) membrane degradation with a slight increase in the ohmic resistance. Thus, the regular test protocol used in this study provided clear insights into the performance degradation (or improvement) mechanism of AEMWE cells.

• Journal of Electrochemical Science and Technology
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• 제13권3호
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• pp.369-376
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• 2022

In this study, the stability of an anion exchange membrane water electrolyzer (AEMWE) cell was evaluated in an on-off cycling operation with respect to an applied electric bias, i.e., a current density of 500 mA cm^-2, and an open circuit. The ohmic and polarization resistances of the system were monitored during operation (~800 h) using electrochemical impedance spectra. Specific consideration was given to the ohmic resistance of the cell, especially that of the membrane under on-off cycling conditions, by consistently feeding the cell with KOH solution. Owing to an excess feed solution, a momentary increase in the polarization resistance was observed immediately after the open-circuit. The excess feed solution was mostly recovered by subjecting the cell to the applied electric bias. Stability tests on the AEMWE cell under on-off cycling with continuous feeding even under an open circuit can guarantee long-term stability by avoiding an irreversible increase in ohmic and polarization resistances.

• Membrane and Water Treatment
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• 제14권2호
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• pp.55-63
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• 2023

In this study, the influence of different IEMs (ion exchange membranes) to performance of the hypochlorite electrolysis unit with Cl₂ recovery stream was investigated. More specifically, Nafion 117-a representative cation exchange membrane (CEM)-and aminated polypheylene oxide (APPO)-an anion exchange membrane (AEM)-were installed in the hypochlorite electrolysis unit, and the performance and the energy efficiency of the units were evaluated and compared. Regardless of whether CEM (Nafion 117) or AEM (APPO) was installed, the rate of hypochlorite generation was increased (by up to 24.3% and 22.2% for Nafion 117 and APPO, respectively) compared with the unit without an IEM. On the other hand, the power efficiency and the optimum operation condition of hypochlorite production units seem to depend on the conductivity and stability of the installed IEM. As the result, between Nafion 117 and APPO, higher performance and efficiency were achieved with Nafion 117, due to excellent conductivity and stability of the membrane.

• Journal of Applied Biological Chemistry
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• 제42권2호
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• pp.85-91
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• 1999

The incubation study was conducted under aerobic and anaerobic conditions to study the release of the kinetically labile forms (i. e. chelating ion or anion forms) of Cd, Cu and Zn in sludge-untreated soil ("Control"), sludge 50 and $100dry\;Mg\;ha^{-1}$ treated soils ("Soil-Sludge mixtures"), and sewage sludge ("Sludge"). The chelating ion and anion exchange membranes were embedded into the samples and incubated for 16 weeks under aerobic and anaerobic condition. The total amounts of chelating ion or anionic forms of Cd were too little to be measured during both aerobic and anaerobic incubation. On the other hand, the total amounts of chelating ion or anionic forms of Cu and Zn slightly increased throughout the incubation period under both incubation conditions. For "Control" and "Soil-Sludge mixtures" treatments, the total amounts of Cu and Zn in chelating ion and anion exchange membrane were little difference between aerobic and anaerobic condition, and the total amounts of chelating ion form of Cu and Zn were not different from the those of anionic form of Cu and Zn. However, for "Sludge" treatment, the total amounts of Cu and Zn in anion and chelating ion exchange membrane were greater under aerobic condition than under anaerobic condition, and the total amounts of chelating ion form of Cu and Zn were greater than those of anion form of Cu and Zn under both incubation conditions.

• 대한화학회지
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• 제27권5호
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• pp.361-367
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• 1983

이온 교환수지에 의한 국산모나자이트 중에 함유된 우라늄을 분리, 회수하기 위하여 강염기성 이온교환수지(Amberlite IRA-900)에 S$O_4^{2-}$ 및 P$O_4^{3-}$ 이온을 흡착시켜 황산우라닐착이온, 인산우라닐착이온 형태로 우라늄을 흡착시켜 적당한 용리액(HN$O_3$ : N$NH_4NO_3$)으로 우라늄을 분리 회수하는 실험을 하였다. 표준우라늄을 사용하였을 때 황산형수지에서 99.3%, 인산형수지에서 99.2%까지 회수하였으며 모자나이트를 황산분해한 모나자이트 황산분해용액 중의 희토류원소들을 제거한 용액을 사용하였을 때는 약 92%까지 회수하였다. 모나자이트 중에 함유된 인산이온의 방해가 없는 것으로 나타났다. 인산형수지에서 우라늄의 회수율이 51% 정도인 것으로 보아 모나자이트를 황산으로 분해하였을 때는 대부분의 우라늄은 황산우라닐착이온으로 된다는 사실도 확인하였다.