• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.272-275
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• 2017

최근 국내 대부분의 원자력 발전소 2차 계통 중 복수 탈염설비의 운전 시 pH를 제어하기 위해 에탄올아민(Ethanolamine, ETA)를 사용하고 있으나 ETA를 적용한 후 발생하는 폐수에 의한 방류수의 화학적 산소요구량(COD) 및 총 질소(TN)의 증가는 심각한 환경적인 문제를 발생 시킨다. ETA가 강이나 하천과 같은 수계로 유입되면 자연적으로 생분해되기 힘들고, 분해부산물이 증가되어 수질을 악화시킬 수도 있다. 이러한 문제점을 해결하기 위해 본 연구에서는 폐경석, 제강슬래그, 저회를 혼합하여 제올라이트화(zeolitization)과정을 통해 새로운 형태의 저비용, 고효율의 ETA 처리용 복합흡착제를 제조하였다. 최적의 흡착 및 이온교환능력을 갖는 복합흡착제는 폐경석, 제강슬래그 및 저회의 혼합조성비를 Mixture Analysis 통계법을 통해 도출하였다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.1
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• pp.1-14
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• 2017

For the removal of cesium (Cs) from high radioactive/high salt-laden liquid waste, this study synthesized a highly efficient composite adsorbent (potassium cobalt ferrocyanide (PCFC)-loaded chabazite (CHA)) and evaluated its applicability. The composite adsorbent used CHA, which could accommodate Cs as well as other molecules, as a supporting material and was synthesized by immobilizing the PCFC in the pores of CHA through stepwise impregnation/precipitation with $CoCl_2$ and $K_4Fe(CN)_6$ solutions. When CHA, with average particle size of more than $10{\mu}m$, is used in synthesizing the composite adsorbent, the PCFC particles were immobilized in a stable form. Also, the physical stability of the composite adsorbent was improved by optimizing the washing methodology to increase the purity of the composite adsorbent during the synthesis. The composite adsorbent obtained from the optimal synthesis showed a high adsorption rate of Cs in both fresh water (salt-free condition) and seawater (high-salt condition), and had a relatively high value of distribution coefficient (larger than $10^4mL{\cdot}g^{-1}$) regardless of the salt concentration. Therefore, the composite adsorbent synthesized in this study is an optimized material considering both the high selectivity of PCFC on Cs and the physical stability of CHA. It is proved that this composite adsorbent can remove rapidly Cs contained in high radioactive/high salt-laden liquid waste with high efficiency.

• Applied Chemistry for Engineering
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• v.29 no.5
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• pp.571-580
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• 2018

In this study, hybrid adsorbents (SS) were prepared by mixing spent coffee grounds (SCG) and sericite, a kind of clay minerals, to adsorb Pb(II) from an aqueous solution. In FT-IR analyses, the main functional groups of SS adsorbents were O-H, C=O and C-N groups. The specific surface area, cation exchange capacity and the pore diameter of SS were larger than those of using SCG and sericite. Formation conditions of the SS adsorbent were the optimum pyrolysis temperature of $300^{\circ}C$, SCG : sericite ratio of 8 : 2, and particle size of 0.3 mm. Langmuir adsorption isotherm was more suitable than Freundlich one, and the maximum adsorption capacity was reached 44.42 mg/g. As a result of the adsorption thermodynamic analysis, the adsorption of Pb(II) onto SS was the physical adsorption and exothermic process in nature. The regeneration of SS adsorbent using distilled water showed 88~92% recovery and the active site of SS adsorbent decreased with increasing the reuse cycle time. As a result, SS adsorbent showed that it can be used to remove Pb(II) easily, inexpensively and efficiently without any pre-treatment from aqueous solutions.

• Korean Journal of Materials Research
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• v.5 no.8
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• pp.966-978
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• 1995

Amidoximated composite fiber adsorbents were prepared for separation of uranium from seawater and characterized by various instrumental techniques, such as IR spectroscopy, CHN elemetal analyzer and SEM. The swelling ratios and yields of the AN-TEGMA and AN-TEGMA-DVB copolymers were decreased with an increase in crosslinklng agents, such as DVB and TEGMA composition. The yield of 85-92% and 82-88% of AN-TEGMA and AN-TEGMA-DVB copolymers respectively were found. The porosity was also decreased with increase in crosslinking compositions, and it was found that the AN-TEGMA-DVB porosity copolymers were smaller than the value of AN-TEGMA copolymer. We investigated that the adsorbent with the composite fiber adsorbents were well dispersed on the surface of Its by SEM. The optimum contents of containing adsorbent in the copolymer was 40 weight percent. The capacity of uraniyl ion through the composite fiber adsorbent containing the amidoxime group was miximized a pH level of 8. Also, if was found that the synthesized composite fiber adsorbent was good material, due to a pH level of 8.3 of seawater, for separation of uraniyl ion from seawater.

• Applied Chemistry for Engineering
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• v.18 no.5
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• pp.459-466
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• 2007

In this study, H-type beta zeolites (BEA) having various metals were used as the adsorbent for the removal of sulfur containing odorants. The different adsorbents containing single or bimetals were utilized to investigate the performance in the individual adsorption of TBM and THT odorants or in the competitive adsorption between them by using a continuous adsorptive bed system. The result shows that the pure H-type BEA zeolite exhibited the highest adsorption capacity for TBM compound, but the higher amount of THT was removed and adsorbed on a HBEA adsorbent having Fe, Pd metal and ZnO oxide. In the case of bimetal containing adsorbents, Cu-Zn/HBEA and Fe-Mo/HBEA showed a higher adsorption capacity for TBM.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.266-270
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• 2018

원자력 방사능 폐기물 또는 원자력 발전소 해체시 발생 가능한 세슘 이온은 인체뿐만 아니라 생태계 환경에도 큰 악영향을 미친다고 알려져 있다. 이러한 세슘 이온은 자연 속으로 손쉽게 스며들어 발생한 지역뿐만 아니라 쉽게 퍼지게 되어 넓은 지역까지 피해를 주게 되며, 반감기가 30년으로써 한번 자연계에 누출되면 장시간 잔존하여 인간 및 생태계에 악영향을 미치게 된다. 세슘이온이 몸속에 들어오게 되면 장에서 몸으로 100% 흡수되며 내장에 축척되어 연조직 전체에 분포하게 되며 갑상선 암과 같은 심각한 위험에 초래하게 된다. 2011년 발생한 후쿠시마 원전 사고 이후 국내에서도 많은 관심을 가지기 시작하였으며, 따라서 수중의 세슘이온을 제거하기 위하여 나노 입자 형태의 기능성을 가진 물질들을 적용한 많은 연구가 이루어지고 있다. 이러한 나노물질들은 수중의 세슘이온 제거에 대하여 우수한 제거효율을 보여주고 있으나 나노 입자 특성상 사용 이후 회수가 어려워 기능성 물질들의 확산 및 축적에 따른 2차 환경오염의 문제점까지 발생하게 된다. 최근 수처리 분야에서 외부 자기장을 주게 되면 자성을 띄게 되는 물질인 자성체에 대한 관심이 급등하고 있다. 이러한 자성체들은 수중에서 별도의 회수 시스템 없이 자성으로 인하여 완벽히 자기분리 된다. 세슘제거에 탁월한 기능성 물질과 완벽한 자기분리가 가능한 자성체를 결합하여 특별한 회수장치 없이 외부 자기장만 주어진다면 수중의 세슘을 효과적으로 제거 또는 처리할 수 있다. 자성체 입자 표면에 흡착제인 프러시안 블루나 제올라이트와 같은 흡착제를 합성하여 수중의 세슘을 제거하는 연구가 활발히 이루어지고 있다. 그러나 기존의 자성체보다 좀 더 높은 자성을 가지고 있으며 외부 자기장에 의해 강하게 반응을 한다고 알려져 있는 강자성체(Ferromagnetic)를 사용하게 된다면 흡착제와 결합 이후 더욱더 강한 자성을 가진 흡착제가 탄생하며 이를 사용하면 높은 처리율뿐만 아니라 높은 슬러지 회수율을 가질 수 있다. 따라서 본 연구는 흡착제나 이온교환수지와 같은 기능성 물질을 사용하여 수중의 세슘을 제거하는 메커니즘과 강자성체가 가지고 있는 강한 자성의 성질을 결합한 복합체 제조에 대한 연구조사를 중점적으로 실시하였다. 본 연구에 의해 연구 조사된 결과를 바탕으로 수중의 세슘 이온에 대하여 높은 제거효율과 회수율을 가지는 새로운 형태의 복합체 제조에 관한 정보를 제공하고자 한다.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.10a
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• pp.296-296
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• 1998

• Proceedings of the KAIS Fall Conference
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• 2007.11a
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• pp.350-352
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• 2007

이산화탄소 분리공정용 흡착제 성능을 향상시키기 위하여 이산화탄소에 대한 우수한 선택성을 나타내고는 아민을 결합시키므로 흡착능을 연구하기 위하여 기존의 상용 흡착제에 담지 하므로써 흡착 및 탈착 성능을 비교, 분석하고자 최적의 아민 담지법, 담지체를 연구하였다.

• Journal of Environmental Health Sciences
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• v.20 no.1
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• pp.62-67
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• 1994

Introduction : Recently, water and environmental pollution becomes serious social problem and high technology makes this pollution accelerate. Hydrogen sulfide, the main subject of our research, is one of the most dangerous air pollutant like SO$_x$ and NO$_x$. The major contaminant in coal gasification is H$_2$S, which is very toxic, hazardous and extremely corrosive. Therefore, control of hydrogen sulfide to a safe level is essential. Although commercial desulfurization process called liquid scrubbing is effective for removal of H$_2$S, it has drawbacks, the loss of sensible heat of the gas and costly wastewater treatment. Many investigations are carried out about high-temperature removal ol H$_2$S in hot coal-derived gas using metal oxide or mixed metal qxide sorbents. It was reported that ZnO was very effective sorbent for H2S removal, but it has big flaw to vaporize elemental zinc above 600\ulcorner \ulcorner As alternative, metal oxides such as CaO, $Fe_2O_3$, TiO$_2$ and CuO were added to ZnO. Especially, different results are reported for $Fe_2O_3$ additive. Tamhankar et al. reported SiO$_2$ with 45 wt% $Fe_2O_3$ sorbent is favorable for removal of H$_2$S and regeneration.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1192-1203
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• 1996

$Al_2O_3-TiO_2$ composite oxide adsorbents which could be applied in high-temperature water were prepared by hydrolysis of aluminum and titanium alkoxide. The prepared adsorbents were calcined at $600{\sim}1400^{\circ}C$ and in order to investigate the various properties - the transition of crystals, thermal properties, and specific surface area, X-ray diffractometry, thermal analysis, FT-IR, SEM and BET method were employed. And the $Co^{2+}$ adsorption characteristics of these adsorbents in high-temperature water were investigated by batch adsorption experiment in a stirred autoclave. Since the adsorption of $Co^{2+}$ on the $Al_2O_3-TiO_2$ adsorbents was irreversible endothermic in the temperature range of $150{\sim}250^{\circ}C$, the standard enthalpy changes of 26, 43, and 80 mol% of $TiO_2$ on $Al_2O_3$ were in the range of $16.5{\sim}26.0kJ{\cdot}mol^{-1}$. The adsorbent of 26 mol% of $TiO_2$ on $Al_2O_3$ which was calcined at $600^{\circ}C$ for 2 hours showed the adsorption amount of $0.1674meq{\cdot}g^{-1}$ in the high temperature water at $250^{\circ}C$.