• KSBB Journal
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• v.24 no.5
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• pp.415-419
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• 2009

In this study, the detoxification methods were evaluated for the removal of fermentation inhibitors from synthetic solution containing the composition similar to the lignocellulosic hydrolysate. The enzyme peroxidase and laccase were used as a biological treatment method. The physico-chemical methods such as adsorption and ion exchange were applied by using activated charcoal and ion exchange resins. The enzyme peroxidase showed a excellent removal of phenolic compounds. The 5-HMF and furfural were completely removed by activated charcoal. The anion exchange resin showed a good result for detoxification of acetic acid. The activated charcoal and ion exchange resins lead to a loss of sugars more or less. The choice of detoxification method must be made after considering the composition and inhibitors in hydrolysates.

• Polymer(Korea)
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• v.30 no.6
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• pp.525-531
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• 2006

In this study, Sulfonated PONF-g-styrene ion exchange fibers were synthesized by radiation induced graft copolymerization. And also, hybride ion exchange fibers, which was combined sulfonated PONF-g-styrene fibers and cationic ion exchange resin, were fabricated by hot melt adhesion method and then their adsorption properties were investigated. ion exchange capacity and water content of hybrid ion exchange fibers increased as compared with those of bead and ion exchange fiber. Their maximum values were 4.76 meq/g and 23.5%, respectively. Adsorption breakthrough time for mercury of hybrid ion exchange fiber was slower than those of bead resin and fibrous ion exchanger. It's value was 130 minutes. Their breakthrough time become short as increasing of pH, and concentration. The initial breakthrough time was observed before and after 10 minutes as increasing of concentration. The adsorption of hybrid ion exchange fibers for $Hg^{2+}\;Pb^{2+},\;Cd^{2+}$ among heavy metals in the mixed solution was observed before 20 min. And also, The adsorption for $Hg^{2+}$ among the heavy metals by hybride ion exchange fibers was observed.

• Membrane Journal
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• v.34 no.2
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• pp.132-139
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• 2024

The ion exchange resin used to remove total dissolved solids (TDS) is used by being packed in a column, and sufficient contact time between the ionic material and the ion exchange resin is required during the ion exchange process. In this study, the ion exchange resin that exhibits high TDS reduction even with a short contact time through pulverization of the ion exchange resin was characterized. The optimal size of resin considering flowability was over 100 ㎛. The highest pulverizing yield were obtained that 250~500 ㎛ size and 100~250 ㎛ size were 67.3% and 36.9%, respectively. Also, the highest yield and the pulverizing time of 100~500 ㎛ size was 87.1% and 2 minutes, respectively. Under batch test conditions, the time to reach a removal rate of 95% and 99% for 250~500 ㎛ resins was 1.82 and 1.96 times faster than non-pulverized ion exchange resin, respectively. The 100~250 ㎛ resins showed 15.9 times and 6.18 times faster, respectively. Under the column test, a total of 1.74 g of NaCl was removed by non-pulverized ion exchange resins, 1.83 g of NaCl was removed by 250~500 ㎛ resins and 1.63 g of NaCl was removed by 100 and 250 ㎛ resins. As the size of the resin decreased, the capacity slightly decreased. As a result, it was observed that the pulverized ion exchange resins could be a method of achieving high TDS removal performance under short contact time.

• Electrical & Electronic Materials
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• v.9 no.3
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• pp.284-290
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• 1996

The electrical properties of bulk galsses in the system Na$_{2}$O-CaO-Al$_{2}$O$_{3}$-B$_{2}$O$_{3}$-SiO$_{2}$ containing 20 to 30mol% sodium which have been subjected to a sodium .tautm. silver ion exchange reaction for 24, 36 and 48 hrs. were analysed by impedance spectroscopy method. Ion exchanged glasses exhibit activation energy values lower than those of the untreated ones. The electrical conductivity increase with sodium content and ion exchanging time. In this experiment the electrical conductivity exhibits a manximum value of 1.78*10$^{-4}$ S/cm at 200.deg. C which contains 30mol% sodium and subjects ion exchange reaction for 48hrs.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.54-55
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• 2018

Reinforced concrete is a building material that is generally used in modern society. Securing the performance of reinforced concrete is directly connected to the durability and longevity of the building. One of the major factors that deteriorate the durability of concrete is harmful ion. Recently, the quality and improvement method of reinforced concrete for penetration of harmful ion has been studied. In this study, the bead type ion exchange resin is substituted for 0%, 3%, and 6% of the fine aggregate volume in the mortar. The speciments underwent underwater curing and were checked for compressive strengths of 3 days and 28 days. From the results of compressive strength, it can be seen that the higher the substitution ratio of the ion exchange resin, the lower the early strength and long-term strength development, especially the early strength development.

• Resources Recycling
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• v.24 no.3
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• pp.51-58
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• 2015

In order to recover tin from the waste tin plating solution, we used the ion exchange method using three types of ion exchange resins. The ion exchange resin with tertiary functional group(Lewatit TP 272) has not adsorption ratio of tin. The ion exchange resin with iminodiacetic functional group(Lewatit TP 207) has high adsorption ratio of tin, but impurity content in the recovered tin solution was relatively high. Whereas, in case of the ion exchange resin with functional group of ethylhexyl-phosphate(Lewatit VP OC 1026), adsorption ratio of tin was less than that of Lewatit TP 207. However, it was possible to remove impurities in the recovered tin solution by controlling the pH of the solution. High purity tin solution can be recovered by removing the organic materials with water washing process.

• Journal of the Korea Convergence Society
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• v.7 no.1
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• pp.155-160
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• 2016

The convergence process utilized both leaching and ion exchange techniques has been investigated for the heavy metals removal in the abandoned mine of Chungyang Province, Korea. The contaminated soil samples by heavy metals from Samkwang mine were analysed by statistical analyses. The highly contaminated soils was initially separated by the flotation process. The selectivity indices were increased with increasing flotation reagents. The selectivity of separation was then improved by the use of both leaching and ion exchange processes in order to extract the heavy metals. The results of this study showed that the higher the sulfuric acid concentration, the leaching rate of heavy metals was increased. The lecheate then was removed by the ion exchange method. The anticipating results might imply that convergence process utilized both leaching and ion exchange techniques would somehow apply for the removal of heavy metals in the abandoned mine.

• Journal of Environmental Science International
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• v.9 no.4
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• pp.325-330
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• 2000

The hydroxyapatite (HAp) for the present study was prepared by precipitation method in semiconductor fabrication and the crystallized at ambient to 95$0^{\circ}C$ for 30min in electric furnace. The ion-exchange characteristics of HAp for various heavy metal ions such as $Cd^{2+}, Cu^{2+}, Mn^{2+}, Zn^{2+}, Fe^{2+}, Pb^{2+}, Al^{3+}, and Cr^{6+}$ in aqueous solution has been investigated. The removal ratio of various metal ions for HAp were investigated with regard to reaction time, concentration of standard solution, amount of HAp and pH of solution. The order of the ions exchanged amount was as follws: $Pb^{2+}, Fe^{3+}>Cu^{2+}>Zn^{2+}>Al^{3+}>Cd^{2+}>Mn^{2+}>Cr^{6+}. The Pb^{2+}$ ion was readily removed by the Hap, even in the strongly acidic region. The maximum amount of the ion-exchange equilibrium for $Pb^{2+}$ ion was about 45 mg/gram of HAp. The HAp would seem to be possible agent for the removal of heavy metal ions in waste water by recycling of waste sludge in semiconductor fabrication.

• Polymer(Korea)
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• v.26 no.1
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• pp.105-112
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• 2002

The low actuation voltage and quick bending response of IPMC(ion-exchange polymer metal composite) are considered attractive for the construction of various types of actuators. In this study, in order to develop a new type actuators by using the IPMC platinum electrode of IPMC are fabricated by using electroless impregnation-reduction method plating. As the platinum-plating times are increased, IPMC performance was improved in terms of bending displacement and force due to the enhanced surface conductivity. In addition, we investigated the basic actuation characteristics of resonance frequency and actuator length as well as the effect of water uptake and ion mobility. Using the classical laminate theory(CLT), a modeling methodology was developed to predict the deformation, bending moment, and residual stress distribution of anisotropic IPMC thin plates. In this modeling methodology, the internal stress evolved by the unsymmetric distribution of water inside IPMC was quantitatively calculated and subsequently the bending moment and the curvature were estimated for various geometry of IPMC actuator.

• Journal of the Korean Chemical Society
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• v.15 no.4
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• pp.199-203
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• 1971

The adsorption method for the determination of the formation constants of the metal complexes with organic acids was developed by using membrane filters. The adsorption method involved the measurements of radioactivities of the adsorbed metal on membrane filters and the filtrate solution after the radioactive metal ion were filtered through membrane filters in the presence of organic ions of varying concentration. Comparing the adsorption method with the ion exchange method, it was seen that the adsorption method was simpler and faster than the ion exchange method. As an example of the metal complex with organic acid yttrium citrate complex was chosen, and the formation constant of the complex obtained by the adsorption method showed $K_f=2.0{\times}10^{-4}(l. mole^{-1})$ at a pH of 7. Also the present study revealed that the carrierfree state of yttrium in aqueous solution was present in the completely ionized state.