• Journal of Integrative Natural Science
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• v.6 no.3
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• pp.151-157
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• 2013

The ion exchange resins were synthesized from 1-aza-18-crown-6 macrocyclic ligand attached to styrene (2th petroleum in 4th class hazardous material) divinylbenzene (DVB) copolymer with crosslinks of 1%, 6%, and 15% by substitution reaction. These synthetic resins were confirmed by chlorine content, elementary analysis, surface area, and IR-spectrum. The object of this study was to seperate the metal ion absorbed in reinforcement water fire extinguishing agent. As the results of the effects of pH, equilibrium arrival time, and crosslink of synthetic resin on metal ion adsorption for resin adsorbent, the metal ions were showed high adsorption at pH 3 or over and adsorption equilibrium of metal ions was about 2 hours. In addition, adsorption selectivity for the resin in water was the order of Al (III) > Ni (II) > Sm (III) ions, adsorbability of the metal ions was in the crosslinks order of 1%, 6%, and 15%.

• Journal of the Korean Electrochemical Society
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• v.18 no.1
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• pp.24-30
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• 2015

To desalinate the aqueous solutions with high salt concentration using the capacitive deionization technology, two resin/membrane capacitive deionization(RMCDI) cells were fabricated by filling mixed ion exchange resins in two different flow channels (spacer and spiral type). The salt removal efficiency of the spacer- and spiral-RMCDI was 77.21 and 99.94%, respectively. Many ions were significantly removed in a spiral RMCDI cell because the feed solution could be more evenly contacted with the ion exchange resins filled on the spiral type flow channel. As the result of the changes of pH and accumulative charges, it was observed that Faradaic reaction was diminished for a spiral RMCDI cell filled by the mixture of cation and anion exchange resins. Therefore, the desalination of the aqueous solutions with high salt concentration by the capacitive deionization technology was proven. In addition, further studies on the optimization of the mixing ratio with ion exchange resins and the introduction of the regeneration process generally occurred in the continuous electrodeionization (CEDI) technology are required to improve the RMCDI technology.

• Applied Biological Chemistry
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• v.2
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• pp.45-52
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• 1961

The decomposition of malathion in dust for mulations prepared from four Korean tales as carriers during storage period has been studied. Amberlite CG-120, a cation exchange resin . which has higher cation exchange capacity than tales, was also used as a carrier in hope of finding out the effect of nagative charge upon the decomposition of malathion. Besides the original talc powders obtained directly from the mines, the hydrogen ion saturated forms were also used as carriers for comparisonal study. The saturated ions for the resin were hydrogen, sodium and magnesium. As the physical properties of the tales, colloid content, water adsorption capacity, PH, specific surface, phosphate fixing capacity and exchangeable canons were determined, and these properties were correlated with the amount of the decomposition. Following results were obtained from the experiment. 1. The malathion in the talc in dust was found to decompose around 10-15% ofthe total withina month. About 50% of the decom position that took place after a month was found to occur within a week. 2. The resin which has higher cation exchange capacity than the tales was highly effective in the decomposition of malathion compared with the tales. 3. In every case the saturation of the exchange complexes with hydrogen ion greatly accelerated the decomposition of malathion. 4. The most highly correlated physical properties with the decomposition were colloid content and specific surface of the tales. 5. The water adsorption and phosphate fixing capacities of the tales were found not to correlate with the amount of malathion decomposed. From the experimental results it was concluded that the active negative spots on the colloidal tales or the resin attract the electropositive phosphorus atom in a malathion molecule thereby inducing the decomposition easier. The presence of hydrogen ion nearby might cause a catalytic effect in the decomposition of malathion.

• Membrane Journal
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• v.27 no.2
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• pp.129-137
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• 2017

In this study, we have developed cation-exchange membranes (CEMs) which can efficiently separate heavy-metal ions among the cations contained in a water system. Sulfonated polyetheretherketone (SPEEK) was used as a base polymer and a powdered chelating resin with strong binding ability to heavy-metal ions was added into it. In order to optimize the performance of the CEM, the content of chelating resin powder and the ion exchange capacity of SPEEK have been controlled. As a result, it was confirmed that the removal efficiency of heavy metal ion was improved by more than 20% by applying the CEM to membrane capacitive deionization (MCDI).

• Journal of Radiation Protection and Research
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• v.24 no.2
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• pp.73-86
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• 1999

The ion-exchange method for the purification of primary coolant has been used broadly in PWR(pressurized water reactor)-type nuclear power plants due to its high decontamination efficiency, simple system, and easy operation. However, its non-selective removal of metal and non-radionuclides shortens its life, resulting in the generation of a large amount of waste ion-exchange resin. In this study, the feasibility of electrodeionization (EDI) was investigated for the purification of primary cooling water using synthetic solutions under various experimental conditions as an alternative method for the ion exchange. The results shows that as the feed flow-rate increased, the removal efficiency increased and the power consumption decreased. The removal rate was observed as a 1000 decontamination factor(DF) at a nearly constant level. For the synthetic solution of 3 ppm TDS (Total Dissolved Solid), the power consumption was 40.3 mWh/L at 2.0 L/min of feed flow rate. The higher removal rate of metal species and lower power consumption were obtained with greater resin volume per diluting compartment. However, the flow rate of the EDI process decreased with the elapsed time because of the hydrodynamic resistivity of resin itself and resin fouling by suspended solids. Thus, the ion-exchange resin was replaced by an ion-conducting spacer in order to overcome the drawback. The system equipped with the ion-conducting spacer resolved the problem of the decreasing flow rate but showed a lower efficiency in terms of the power consumption, the removal rate of metal species and current efficiency. In the repeated batch operation, it was found that the removal efficiency of metal species was stably maintained at DF 1000.

• Resources Recycling
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• v.30 no.4
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• pp.54-63
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• 2021

Vanadium and tungsten can be obtained by separating/recovering the leaching solution from a spent SCR DeNO_X catalyst using the soda roasting-water leaching process. Therefore, in this study, the adsorption/desorption mechanism of vanadium and tungsten in an ion-exchange column was investigated using Lewatit MonoPlus MP 600, a strong basic anion exchange resin. The operating conditions for the separation of vanadium and tungsten in the ion-exchange column was intended to present. By conducting a continuous adsorption experiment in a pH 8.5 solution, the adsorption capacity of vanadium and tungsten was found to be 44.75 and 64.92 mg/(g of resin), respectively, which showed that the adsorption capacity of tungsten was larger than that of vanadium because of the difference in ion charge. Vanadium has a higher affinity for MP 600 than tungsten. Consequently, as the vanadium-containing solution is eluted through the ion exchange resin onto which tungsten is adsorbed, the adsorbed tungsten is exchanged with vanadium and desorbed. A continuous experiment was performed with a solution of vanadium and tungsten prepared at the same concentration as the spent SCR DeNO_X catalyst leachate. The adsorption capacity of vanadium was found to be 48.72 mg/(g of resin) and 80% of the supplied vanadium was adsorbed; in contrast, almost no tungsten was adsorbed. Therefore, vanadium and tungsten were separated effectively. The ion exchange resin was treated with 2 M HCl at 15 mL/h, and 97.7% of the vanadium(99% purity) could be desorbed. After desorption, NH₄Cl was added to precipitate ammonium polyvanadate at 90℃ and recover 93% of the vanadium.

• Journal of Pharmaceutical Investigation
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• v.41 no.2
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• pp.67-73
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• 2011

Ion exchange resins can be one of the good carriers for sustained drug release. However, the sustained release may not be enough only with themselves and hence film coating with rate controlling polymers can be applied to have a further effect on the drug release. Due to the environmental and economic issues of organic solvent for the polymer coating, aqueous polymeric systems were selected to develop dosage forms. Among the many aqueous polymeric dispersions for the film coating, EC (ethylcellulose) based polymers such as Aquacoat$^{(R)}$ ECD and Surelease$^{(R)}$ were evaluated.A fluid-bed coating was applied as a processing method. The drug release rate was quite dependent on the coating level so the release rate could be modified easily by changing different levels of the coating. The drug release rate in the Aquacoat$^{(R)}$ coated resin particles was strongly dependent on curing, which is a thermal treatment to make homogeneous films and circumvent drug release changes during storage. After dissolution test using the compressed tablets in which the coated resin particles are contained, inhomogeneous coating and even pores could be observed showing that the mechanical properties of EC were not resistant to granulation and compaction process. However, when tablets were prepared in different batches, the release profiles were almost identical showing the feasibility of the coated resin particle as incorporated into the tablet formulation.

• Resources Recycling
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• v.20 no.6
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• pp.28-36
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• 2011

The adsorption of nickel(Ni) from sulfuric acid solution was carried out by ion exchange method. A series of batch tests in synthetic solutions were carried out using Lewatit Monoplus TP 220 resin. The following experimental parameters, such as temperature, shaking rate, reaction time, pH, resin dosage and concentration of nickel ions etc. were investigated to establish the effective optimum conditions of nickel adsorption. The solution pH(2.0~5.0) and shaking rate had little effects on the adsorption of nickel and adsorption time of 72hours was required to reach equilibrium. The experimental results show a good agreement with Feundlich isotherm and pseudo-second order reaction. The adsorption behavior of Ni obtained from synthetic solution was compared with that of waste electroplating solution. Elution of nickel from loaded resin increased with increase in $H_2SO_4$ concentration.

• Journal of the Korean Chemical Society
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• v.24 no.3
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• pp.239-244
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• 1980

An anion exchange method for separating the individual rare earth elements in monazite into enriched fractions has been developed. The complexed rare earth ions with EDTA at pH 8.4 pass through the anion resin bed. The absorption order of the complexed ions was in accord with that of the stability constants of the complexes. The elution of a mixture of all the rare earths through an ion-exchange bed with an ammonia-buffered solution of EDTA indicated that this chelating agent is as effective for separating the light rare earths. The separation results of each ion obtained from their elution fractions are 55% to 98%.

• Journal of environmental and Sanitary engineering
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• v.12 no.1
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• pp.15-23
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• 1997

The anionic exchange resins with the Dowex-1 and Amberlite CG-400 form were transformed into resin of sulfate and acetate acid form, respectively. The uranyl complex ions with SO$_{4}$$^{2-}$ and CH$_{3}$COO$^{-}$ were adsorbed on the anion exchange resion mentioned above, and these complex ions were eluted as mixture eluents of 0.7M HNO$_{3}$ - 0.5M NH$_{4}$NO$_{3}$ by anion exchange chromatography. The optimum adsorption conditions of uranyl anion complex ions adsorbed on the upper of the resin colmun were 1.5-2.0 ml/min of flow rates at pH 2.0 and adsorptive power of uranyl complex ion of sulfuric acid type were nearly consistent with the Caussion normal distribution curve, whereas the elution state of UO$_{2}$(Ac)$_{2}$$^{4-}$ with acetic acid type was departed. The weighing form obtained from resin of sulfuric acid and aceric acid type was U$_{3}$O$_{8}$ whose recovery was 91.7%. The possibility of recovering uranium from the monazite sulfate solution using a strong base anion resin, Amberlite CG-400(sulfate form), was successfully recovered more than 90%.