• Proceedings of the Korean Environmental Sciences Society Conference
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• 1998.10a
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• pp.184-187
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• 1998

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.193-198
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• 1997

The purpose of this study was to find out a suitable resin to remove $NO_3-N$ from groundwater. Four different commercial resins differentiated by type, porosity and nitrate selectivity were used to compare the performance of nitrate removal. Gel type, Type 2 anion exchange resin was preferable when anion concentration of raw water was low. But efficiency of this resin decreased as flow rate increased. However, macroporous type resins were not affected by increasing flow rate. Macroporous resins were preferable when anion concentrations in raw water were high and high flow rate was proposed. And the general type resin showed better efficiency when sulfate concentrations were low. However the nitrate selective resin had better efficiency in treating raw water of high sulfate concentration. From the results, it may be drawn that nitrate selective resins are preferable to general type when a sulfate concentration in groundwater is over 50mg/l.

• Analytical Science and Technology
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• v.17 no.2
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• pp.91-97
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• 2004

Cryptand ion exchange resins were synthesized with 1-aza-15-crown-5 macrocyclic ligand attached to styrene divinylbenzene (DVB) copolymer with crosslink of 1%, 2%, 5% and 10% by substitution reaction. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time, dielectric constant of solvent and crosslink on adsorption of uranium ($UO{_2}^{2+}$) ion were investigated. The uranium ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium ($UO{_2}^{2+}$), magnesium ($Mg^{2+}$), neodymium ($Nd^{3+}$) ion. The adsorption was in order of 1%, 2%, 5%, and 10% crosslink resin and adsorption of resin decreased in proportion to order of dielectric constant of solvents.

• Polymer(Korea)
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• v.26 no.2
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• pp.153-159
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• 2002

In order to remove $NO_3;^-$ ion from ground-water, fibrous ion -exchangers, APP-g-GMA, were synthesized by GMA grafting onto PP trunk polymer with E-beam accelerator for pre-irradiation. Their degrees of grafting and amination yield increased up to $60^{\circ}C$ and showed maximum values as 133%, 88%, respectively. And their swelling ratio and ion exchange capacity at the maximum values are 86%, 2.5 meq/g, respectively which was higher than commercial ion-exchangers such as IMAC HP555 and Amberlite IRA 400. Optimum adsorption condition of $NO_3;^-$ ion was measured at pH 5~6 and -Cl form of APP-g-GMA containing trimethylammonium group showed the highest adsorption capacity.

• Resources Recycling
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• v.21 no.5
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• pp.50-57
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• 2012

A comparative study has been carried out on the removal of impurities such As, Sb, Bi from the copper sulfate solution by ion exchange resin containing aminophosphosphonic acid as functional group. The various parameters which affect the removal of impurities; such as the reaction temperature, the reaction time, the amount of ion-exchange resins, the concentration of sulfuric acid in electrolyte, were studied. The basic experimental results showed that about 88% of Sb & 94% of Bi can be adsorbed in these chelate resins and removed from the copper sulfate solutions but As was removed below 10% from the solutions. And the selective elution of Bi and Sb from the adsorbed ion exchange resin also can be achieved by $H_2SO_4$ or HCl solutions. The results also showed that 98.1% of Sb and 96.6% of Bi can be adsorbed from the copper sulfate solutions after 2 Bed-volume of continuous ion exchange column test.

• Applied Chemistry for Engineering
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• v.16 no.6
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• pp.731-736
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• 2005

In this paper, immobilization of lipase (Rhizomucor miehei, Rhm) onto ion-exchange resin pretreated with oleic acid and its application were studied. Immobilization efficiency was reached to 82% when weakly basic anion exchange resin, Duolite A-568, was used. Immobilized Rhm was stable in water, chloroform and hexane, however, unstable in alcoholic solvents. When immobilized Rhm was applied to the esterification reaction of glycerol and fatty acid, content of DG in the product mixture was ca. 80 mol% and 1,3-DG in total DG reached to 98%.

• Journal of the Korean Chemical Society
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• v.23 no.3
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• pp.141-151
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• 1979

The selective absorption of metal ions by chelating agent-loaded resins was studied in aqueous media. The resins were prepared by loading the conventional anion exchange resin, Dowex 1-X8 (50 to 100 mesh) with chelating agents containing sulfonic group, such as 8-hydroxy-quinoline-5-sulfonic acid (HQS) and 7-nitroso-8-hydroxyquinoline-5-sulfonic acid (NHQS). The stability of the resin was markedly influenced by the following factors; (1) the affinity and concentration of anions in the external solution, (2) the pH of the media. The optimum conditions for the absorption of metal ions were determined with respect to the pH, shaking time, and the effect of anion concentration in the medium. Under the optimum condition the order of the absorption of metal ions such as Fe(Ⅲ), Cu(Ⅱ), Pb(Ⅱ), and Zn(Ⅱ) was in accord with that of the stability constants of the chelates. The total capacities of the resins were found in the range of 0.6∼1.6 mmole metal per gram.

• Journal of the Korean Chemical Society
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• v.31 no.1
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• pp.45-54
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• 1987

Dowex 1-X8 resin ion exchanged with calcon carboxylic acid (CCA-Dowex 1-X8) and 2-methyl-8-hydroxyquinoline(MHQ) impregnated-Amberlite XAD-4 resin (MHQ-XAD-4) were examined for the separation and preconcentration of ferric ion from the various matrices. The stabilities of these resins were investigated, and their capacities on ferric ion were also measured. The effect of pH on the adsorption of ferric ion and matrix ions, such as Al(Ⅲ) and Ca(Ⅱ), was investigated to determine the optimun pH ranges. Separation and preconcentration of iron in aluminium foil and mineral water samples were studied by elution method with these resin columns. The recovered ions by 10ml of 2F nitric acid was determined by flame atomic spectrophotometry. SP-Sephadex C-25 column was used to separate ferrous and ferric ion in mineral water by stepwise elution with ferrozine and 1 % ascorbic acid-ferrozine solution. The concentrated and separated each ion could be determined spectrophotometrically at the analytical wavelenth of Fe(Ⅱ)-ferrozine complex (562nm).

• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.697-702
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• 2011

Ion exchange resins have been synthesized from chloromethylated styrene-1,4-divinylbenzene (DVB) with 1%, 2%, 5% and 15%-crosslinkage and macrocyclic ligand of $OenNdien-H_4$ by copolymerization. The adsorption characteristics of uranium (${UO_2}^{2+}$), potassium ($K^+$) and neodymium ($Nd^{3+}$) metallic ions have been investigated. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time, and crosslinkage on adsorption of metallic ions were also studied. The uranium ion showed the fast adsorption on the resins above pH 3. The optimum equilibrium time for the adsorption of metallic ions was about two hours. The adsorption selectivity determined in methanol solution was in increasing order uranium (${UO_2}^{2+}$) > potassium ($K^+$) > neodymium ($Nd^{3+}$) ion. Moreover, the adsorption was increased with the crosslinkage concentration in order of 1%, 2%, 5% and 15%-crosslinkage resin.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.131-132
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• 2004

원자력연구소에 보관 중인 오염 토양폐기물을 토양 세척법으로 제염하여 비 방사성폐기물화 한다면 그 부피를 10% 이하로 저감시킬 수 있으며 연구소의 고체 방사성폐기물 저장 용량을 크게 늘릴 수 있다. 1988년 발견 당시 오염 토양 폐기물의 주요 방사성 핵종은 Co-60 이었는데 시간경과에 따라 Cs-134, 137 이 주요 방사성 핵종이 되었다. 오염토양 폐기물의 60 % 이상은 방사능 농도가 극히 낮아 물리적으로 입도를 분리하거나 수 세척에 의해 비 방사성폐기물화 할 수 있음을 파악하였다.(중략)