• Membrane and Water Treatment
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• v.13 no.1
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• pp.1-6
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• 2022

The regulations of the International Maritime Organization (IMO) have been steadily strengthened in ship emissions. Accordingly, there is a growing need for development of related technologies for the removal of contaminants that may occur during the treatment of SOx and NOx using a wet scrubber. However, this system also leads to wastewater production when the exhaust gas is scrubbed. In this research, we evaluated the performance of an ion selective resin process in accordance with scrubber wastewater discharge regulations, specifically nitrate discharge, by the IMO. Accelerated real and synthetic wastewater of wet scrubbers, contained high amounts of TDS with high nitrate, is used as feed water in lab scale systems. Furthermore, a pilot scale dissolved air flotation (DAF) using microbubble generator with ion exchange resin process was combined and developed in order to apply for the treatment of wet scrubber wastewater. The results of the present study revealed that operating conditions, such as resin property, bed volume (BV), and inlet wastewater flow rate, significantly affect the removal performance. Finally, through a pilot test, DAF with ion exchange resin process showed a noticeable improvement of the nitrate removal rate compared to the single DAF process.

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.05a
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• pp.37-37
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• 2002

• Membrane and Water Treatment
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• v.3 no.1
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• pp.63-76
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• 2012

Mother liquid discharged from a salt-manufacturing plant was electrodialyzed at 25 and $40^{\circ}C$ in a continuous process integrated with $SO_4{^{2-}}$ ion low-permeable anion-exchange membranes to remove $Na_2SO_4$ and recover NaCl in the mother liquid. Performance of electrodialysis was evaluated by measuring ion concentration in a concentrated solution, permselectivity coefficient of $SO_4{^{2-}}$ ions against $Cl^-$ ions, current efficiency, cell voltage, energy consumption to obtain one ton of NaCl and membrane pair characteristics. The permselectivity coefficient of $SO_4{^{2-}}$ ions against $Cl^-$ ions was low enough particularly at $40^{\circ}C$ and $SO_4{^{2-}}$ transport across anion-exchange membranes was prevented successfully. Applying the overall mass transport equation, $Cl^-$ ion and $SO_4{^{2-}}$ ion transport across anion-exchange membranes is evaluated. $SO_4{^{2-}}$ ion transport number is decreased due to the decrease of electro-migration of $SO_4{^{2-}}$ ions across the anion-exchange membranes. $SO_4{^{2-}}$ ion concentration in desalting cells becomes higher than that in concentration cells and $SO_4{^{2-}}$ ion diffusion is accelerated across the anion-exchange membranes from desalting cells toward concentrating cells.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3665-3676
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• 2023

The use of ion exchange resins to remove ionic impurities from solution is prevalent in industrial process systems, including in the primary heat transport system (PHTS) purification circuit of nuclear power plants. Despite its extensive use in the nuclear industry, our general understanding of ion exchange cannot fully explain the complex chemistry in ion exchange beds, particularly when operated at or near their saturation limit. This work investigates the behaviour of mixed-bed ion exchange resin, saturated with species representative of corrosion products in a CANDU (Canadian Deuterium Uranium) reactor PHTS, particularly with respect to iron chemistry in the resin bed and the removal of lithium ions from solution. Experiments were performed under deaerated conditions, analogous to normal PHTS operation. The results show interesting iron chemistry, suggesting the hydrolysis of cation resin bound ferrous species and the subsequent formation of either a solid hydrolysis product or the soluble, anionic Fe(OH)₃^-.

• Korean Chemical Engineering Research
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• v.55 no.4
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• pp.535-541
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• 2017

On the basis of 200 ppm of Ag and 120 l/h of feed flow rate, we built a pilot plant of an ion exchange fiber system having an double tube type ion exchange chamber with strong base ion exchange fiber (FIVAN A-6) which was designed to replace fibers easily and to eliminate the need for a fixture. The following results were obtained for the double tube type of ion exchange fiber system with an ion exchange capacity of 4.6 meq/g for Ag. The adsorption process was operated in the range of 40~90 l/h after confirming the effect of the flow rate and, pH did not affect formation of complex ion of Ag in the range of pH 7~12. In the case of backwash process, the recovery rate of Ag was tested in the range of 60~120 l/h and comparative experiments were carried out using NaOH, $NH_4Cl$, and NaCl as the chemicals for backwash. Although the desorption time was shortened at higher concentration, the desorption efficiency per mol was lowered. Therefore, it was confirmed that the desorption time and the concentration should be well balanced to operate economically. The desorption pattern of the backwash process is slower than the adsorption process and takes a lot of time. The results showed that the Ag adsorption ratio was 99.5% or more and the Ag recovery ratio was 96% or more, and commercialization was possible.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.05a
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• pp.130-132
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• 1994

We fabricated Ag ion exchange glass waveguide. Generally, ion-exchange glass waveguide. are suitable for passive integrated optical components such as directional and star couplers. Its advantages include low loss, ease of fabrication, and low material cost. So, we faricated Ag ion-exchange glass waveguides in AgNO$_3$ melt solution from 2 mole %. And we used Sodalime glass as a substrate in the fabrication process. As the results, we observed multivalent ion-exchange in a typical sodalime glass. Diffusion coefficient and depth are predicted by actual experimental data of Stewart. The exchange rate in silver-ion-exchanged waveguides are compared to the exchange time of waveguide fabrication.

• Membrane Journal
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• v.30 no.2
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• pp.79-96
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• 2020

Secondary energy conversion systems have been briskly developed owing to environmental issue and problems of fossil fuel. They are basically operated based on electro-chemical systems. In addition, ion exchange membranes are one of the significant factors to determine performance in their systems. Therefore, the ion exchange membranes in suitable conditions must be developed to improve the performance for the electro-chemical systems. These ion exchange membranes can be classified into various types such as cation exchange membrane, anion exchange membrane and bipolar membrane. Their membranes have distinct characteristics according to the chemical, physical and morphological structure. In this review, the types of ion exchange membranes and their fabrication processes are described with main characteristics. Moreover, applications of ion exchange membranes in newly developed energy conversion systems such as reverse electrodialysis, redox flow battery and water electrolysis process are described including their roles and requirements.

• Membrane Journal
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• v.32 no.4
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• pp.209-217
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• 2022

Ion exchange membrane (IEM) is an important class of membrane applied in batteries, fuel cells, chloride-alkali processes, etc to separate various mono and multivalent ions. The membrane process is based on the electrically driven force, green separation method, which is an emerging area in desalination of seawater and water treatment. Electrodialysis (ED) is a technique in which cations and anions move selectively along the IEM. Anion exchange membrane (AEM) is one of the important components of the ED process which is critical to enhancing the process efficiency. The introduction of cross-linking in the IEM improves the ion-selective separation performance due to the reduction of free volume. During the desalination of seawater by reverse osmosis (RO) process, there is a lot of dissolved salt present in the concentrate of RO. So, the ED process consisting of a monovalent cation-selective membrane reduces fouling and improves membrane flux. This review is divided into three sections such as electrodialysis (ED), anion exchange membrane (AEM), and cation exchange membrane (CEM).

• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.157-162
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• 2012

In this study, we have for the first time applied increased surface area fractional precipitation in order to decrease the particle size of the anticancer agent paclitaxel from plant cell cultures. When compared with the case where no surface area increasing material was employed, the addition of ion exchange resin as a surface area increasing material resulted in a considerable decrease in the size of the paclitaxel precipitate. When ion exchange resin was used, the paclitaxel particles were four to five times smaller, having less than a 20 ${\mu}m$ radius, than those obtained in the absence of ion exchange resin. This is presumably because the growth of paclitaxel particles was impeded by the addition of ion exchange resin. The size of the paclitaxel precipitate also depended on the material used to increase the surface area, a result considered to be due to differences in the affinity between the particular ion exchange resin used and the paclitaxel particles. The yield of paclitaxel was significantly improved when ion exchange resin was used as a material to increase surface area. Paclitaxel, with a reduced particle size due to the addition of a surface area increasing material during the fractional precipitation process, is believed to be particularly useful for practical applications of the drug.

• Journal of Korean Society of Water and Wastewater
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• v.11 no.1
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• pp.42-52
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• 1997

The affection of activated carbon on the dissolved aluminum ion in drinking water has been observed. In addition, the aluminum ion removal capability of activated, alumina, chitosan, and ion exchange resin have been investigated. Experimental results indicated that the coal based activated carbon released considerable amount of aluminum ion to the water while coconut shell based activated carbon didn't. However the release was not continuous. Activated alumina didn't show any recognizable removal capability for aluminum ion in water. Particulate chitosan has removed aluminum ion although dissolved chitosan has not. However it need to development a regeneration process for chitosan to be an effective mean for aluminum ion removal. Ion exchange resin showed a reliable aluminum ion removal capability. The ion exchange capacity was 2.63 meq/g resin for the aluminum ion in drinking water.