• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.05a
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• pp.278-279
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• 2006

본 연구에서는 수중 silica 제거에 이온교환수지의 성능이 실험되었다. 음이온 단일수지에 비해 양이온/음이온 혼합수지가 silica제거에 효과적이었고, 혼합수지에서 온도가 높을수록 교환반응속도는 빨랐다. 음이온과 양이온교환능은 용액의 pH를 변화를 측정하여 해석할 수 있었다. 용액에 공존하는 양이온인 $Na^+$는 혼합수지에서 pH변화에 영향을 주는 물질이었고, 이러한 pH의 변화는 silica의 제거능에 영향을 주었다. 각 온도에서 도달된 평형농도로부터 각 수지에 대한 silica의 선택도계수가 측정되었다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.3
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• pp.173-179
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• 2010

In a HLW repository, the buffer is exposed to an elevated temperature due to a radioactive decay and geochemical conditions for a long time and such a hydrothermal condition may cause a significant loss of its barrier function. This study carried out hydrothermal tests with a domestic smectite clay to investigate the changes in the expandibility, layer charge, and cation exchange capacity of the smectite. When the temperature and potassium concentration in solution was increased for the hydrothermal treatments, the expandibility decreased, the layer charge negatively increased, and the CEC also decreased.

• Applied Chemistry for Engineering
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• v.10 no.2
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• pp.206-211
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• 1999

Mixed-bed ion exchange performance was studied experimentally with variations of cation to anion resin ratio, resin weight and temperature at ultralow sodium chloride solution concentrations of less than $1.0{\times}10^{-4}M$. Analyzing the effluent concentration histories the performance test was examined as a function of tested solution volume for a laboratory-scale continuous flow column until both the cation and anion-exchange resins were exhausted. Initial leakage was observed for both cation and anion breakthrough curves, but serious at cation breakthrough curve because of low selectivity coefficient. The slope of breakthrough curve was affected by selectivity coefficient and temperature. The slope of anion breakthrough curve was steep because of the large selectivity coefficient, and ion exchange rates increased as temperature increased. The temperature effect decreased as the total volume was increased or as the resins were exhausted.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.248-248
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• 2003

층상이중수화물(Layered Double Hydroxides, LDH)은 층 사이에 무기물 음이온이 있는 2차원 충상구조물로서 이들 층 사이의 공간에 이동 가능한 수화된 음이온의 존재로 전하균형을 이룬다. 층 사이의 음이온은 교환이 가능하며, 나머지의 공간은 물분자로 채워져 있다. 이러한 특성을 응용하여 LDH는 촉매, 음이온 교환제, 흡착제, 담체로 사용가능하며, 특히 음이온 교환능이 있는 소재로 고분자에 적용되고 있으며, 층간에 염료를 삽입한 복합체의 제조 둥에 관한 연구가 활발히 이루어지고 있다. 이의 적용에서 LDH의 입도는 결정적인 한계 요인으로 작용하기도 한다. 본 실험에서는 Mg-Al-NO$_3$ 층상이중수산화물(Mg-Al-NO$_3$-LDH)을 공침전법으로 합성하고, 양이온의 농도와 공침시 pH 및 교반조건의 변화가 생성된 LDH의 결정상, 형상, 입도, 및 양이온교환능에 미치는 영향을 알아보았다. 특히 초음파 분산법을 적용하는 경우 생성되는 LDH 입자크기의 미세화에 효과적인 것을 확인 할 수 있었다.

• Journal of the Mineralogical Society of Korea
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• v.15 no.4
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• pp.243-257
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• 2002

Ca-type and Na-type bentonites show the great difference of some physicochemical properties. Na exchanged bentonite is mainly used for the foundry and construction materials in domestic utilization. This study tries to identify in detail the differences of some physicochemical properties and thermal properties between Ca-type and Na-type bentonites. Also the adsorption behavior and interlayer expansion for the HDTMA (Hexadecyltrimethylammonium) exchanged and CP (Cetylprydinium) exchanged Ca-type and Na-type bentonites were compared. Na-type bentonite shows the strong alkaline property, high viscosity and swelling compared to Ca-type bentonite. However, two types are very similar for the cation exchange capacity and MB (Methylene Blue) adsorption. The decomposition of adsorbed and interlayer water of Na-type bentonite is caused in the lower temperature than Ca-type bentonite. And Ca-type bentonite shows the decomposition of structural water in the lower temperature than Na-type bentonite. The interlayer expansion of montmorillonite resulted to the intercalation of HDTMA and CP into bentonite is so strongly caused from 12～15 $\AA$ to $40\AA$ (basal spacing). HDTMA-bentonite is almost expanded to $37～38\AA$ when 200% CEC equivalent amount of HDTMA is added, and CP-bentonite is fullly expanded to 40 $\AA$ in the 140% CEC equivalent amount of CP It means that CP causes the stronger interlayer expansion of montmorillonite and easier adsorption than HDTMA. Adsorption behaviors of CP into bentonite is so stable and continuously sorbed in the proportion to the treatment of amount until 200% of the CEC equivalents. CP-bentonite shows the same adsorption behavior regardless of Ca-type or Na-type montmorillonite.

• Journal of the Korean Geotechnical Society
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• v.16 no.6
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• pp.95-95
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• 2000

(No Abstract.see full/text)

• Journal of the Korean Geotechnical Society
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• v.16 no.6
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• pp.97-103
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• 2000

지반내 중금속의 저류와 이동에 대한 가장 중요한 인자는 토양 간극수의 pH이다. 점토의 완충능을 kaolinite, hectorite, attapulgite, Na-bentonite와 같은 4가지 점토에 대하여 연구하였다. 완충능의 크기는 hectoriteattapulgite>kaolinite의 순으로 나타났다. 완충능의 크기는 지반내 탄산염 함량과 양이온 교환능력이 완충능의 크기에 가장 영향을 미치며 유기물 함량과 비표면적의 영향은 적었다. 토양의 완충능을 모델링하기 위하여 수소 이온과 토양표면의 화학반응 기간의 화학반응을 정전흡착 모델을 이용하여 모델링하였다. 또한 탄산염 함량과 양이온 교환능력을 함수로 하는 회귀식을 제안하였다. 모델 검증을 위하혀 모델 예측치와 실험치를 비교하였는데 정전 흡착모델을 이용한 예측치가 실험치와 근사한값을 나타냈다.

• Polymer(Korea)
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• v.24 no.6
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• pp.763-769
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• 2000

The multifunctional cation exchangers, sulfonated polypropylene-g-(acrylic acid/styrene) [PP-g-(AAc/Sty)] were synthesized by the irradiational grafting of AAc and Sty onto PP staple fabric with electron beam accelerator and its subsequent sulfonation. The highest degree of grafting obtained was 190% at a monomer mixture of 30 vol% AAc: 70 vol% Sty and a solvent mixture of 30 vol% water : 70 vol% methanol and the degree of grafting decreased with an increase of the AAc content in the monomer mixture at constant solvent content. Maximum ion exchange capacity of the copolymer was 4.6 meq/g. The Li$^{+}$ adsorption ability of the copolymer synthesized in the study was the best among PP-g- AAc, sulfonated PP-g-Sty, and sulfonated PP-g-(AAc/Sty).).

• Journal of Bio-Environment Control
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• v.5 no.1
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• pp.43-49
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• 1996

This study was conducted to investigate the effects of artificial zeolite and various ion exchangers supplemented in rockwool on the ion exchangability of muskmelon. The results obtained were as follows ; Plant height was higher in the treatment of Ca type artificial zeolite as of 131.2cm than that of control as of 124cm, and same trends were shown in fresh weight of leaf and stem. Fruit weight was increased by supplement of artificial zeolite, but there were no significant differences in the sugar degree and external appearance as influenced by supplementing artificial zeolite. Supplement of artificial zeolite stabilized the pH and increased the ion exchange capacity of nutrient solution. Nutrient absorption was more favorable and led to growth promotion. This study was demonstrated that supplement of artificial zeolite in rockwool slab was improved the stabilization of root environment and increased ion uptake of muskmelon plant.

• Journal of the Korean Chemical Society
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• v.36 no.1
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• pp.137-146
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• 1992

The adsorption properties of CO on the cation exchanged natural zeolite, $K_{111}$ and cation effects upon the CO adsorption were studied. $Na^+-,\;Cu^{2+}-\;and\;Ba^{2+}-\;K_{111}$ exhibited relatively good CO adsorption capacities and $Ba^{2+}- K_{111}$ treated by 0.4 N-$BaCl_2$ solution proved itself as the best adsorbent and superior to the synthetic zeolite 4A and 5A. The observed adsorption tendency due to the cations were in the order of $Ba^{2+}>Cu^{2+}>Na^+>K^+>Mg^{2+}>Ca^{2+}$. The cation exchanged number per unit cell as well as the kind of cation which forms bond with CO molecules in different intensities and other mineral factors such as pore size indicated to be important factors to the CO adsorption properties. The CNDO/2 calculations were performed to compare the adsorption tendencies and CO interaction energy of cations in $K_{111}$.