• 대한방사선기술학회지:방사선기술과학
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• 제46권2호
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• pp.141-149
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• 2023

The Korea Institute of Radiological and Medical Sciences plans to produce ²²⁵Ac, a therapeutic radio-pharmaceutical for precision oncology, such as prostate cancer. Radon, a radioactive gas, is generated by radium, the target material for producing ²²⁵Ac. The radon concentration is expected to be about 2000 Bq·m^-3. High-concentration radon-generating facilities must meet radioactive isotope emission standards by lowering the radon concentration. However, most existing studies concerning radon removal using activated carbon filters measured radon levels at concentrations lower than 1000 Bq·m^-3. This study measured ²²²Rn removal of coconut-based activated carbon filter under a high radon concentration of about 2000 Bq·m^-3. The ²²²Rn removal efficiency of activated carbon impregnated with triethylenediamine was also measured. As a result, the ²²²Rn removal amount of the activated carbon filter showed sufficient removal efficiency in a ²²²Rn concentration environment of about 2000 Bq·m^-3. In addition, despite an expectation of low radon reduction efficiency of Triethylenediamine-impregnated activated carbon, it was difficult to confirm a significant difference in the results. Therefore, it is considered that activated carbon can be used as a radioisotope exhaust filter regardless of whether or not Triethylenediamine is impregnated. The results of this study are expected to be used as primary data when building an air purification system for radiation safety management in facilities with radon concentrations of about 2000 Bq·m^-3.

• 공업화학
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• 제17권3호
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• pp.280-285
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• 2006

본 연구에서는 KOH를 첨착한 활성탄에서 황화수소의 흡착특성을 동특성 실험을 통해 관찰하였다. 특히 수분과 산소 농도가 흡착특성에 미치는 영향을 확인하였다. KOH를 첨착시킨 활성탄의 표면적, 세공부피 및 크기 분포 등의 기공 특성들은 질소 흡탈착 등온선을 이용하여 측정하였으며, 흡착량은 Langmuir와 Freundlich 등온식으로 모사하였으며 KOH를 첨착시킨 활성탄에서 황화수소의 흡착량은 Langmuir 등온식으로 잘 묘사되었다. 산소 농도의 증가는 KOH 첨착 활성탄의 황화수소 흡착성능에 큰 영향을 나타내었다.

• 한국연초학회지
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• 제27권2호
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• pp.171-177
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• 2005

Coconut based activated carbon and silica-gels were impregnated with 3-aminopropyltri ethoxysilan(APS) and N-(2-aminoethyl)-3-aminopropyl triethoxysilane (AEAPS) in order to investigate the effect of the amine group and the pore size of the supports on the removal of hydrogen cyanide(HCN) and aldehydes in mainstream smoke(MS). The physicochemical properties of the supports were analyzed by using thermal gravity analyzer(TGA), $N_2$ adsorption and desorption isotherms$(BET,\;N_2)$, and SEM-EDS. According to our experimental data, there was no significant difference in the delivery amount of HCN and aldehydes of non-functionalized silica-gels having meso-pores bigger than $20\AA$. In the case of silica-gels functionalized with APS(APS silica-gel), the delivery amounts of hydrogen cyanide(HCN) and aldehydes decreased with the increase of APS concentration. Silica-gel functionalized with AEAPS(AEAPS silica-gel) showed higher removal efficiency than that of APS silica-gels. The delivery amounts of HCN and aldehydes of activated carbon impregnated with APS and AEAPS increased with the increase of the APS and AEAPS concentrations. In accordance with the specific surface area analysis results, APS and AEAPS molecules decreased the specific surface area by blocking the micro-pores of the activated carbon. The volatile organic components removal efficiency by the micro-pores was higher than that of the amine group impregnated into the activated carbon.

• Carbon letters
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• 제7권3호
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• pp.161-165
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• 2006

Activated carbon fiber could be prepared at 973 K by catalytic activation using potassium hydroxide. Phenol resin fiber (Kynol) was impregnated with potassium hydroxide ethanol solution, carbonized and activated at 973 K, resulting in activated carbon fibers with different porosities. The potassium hydroxide accelerated the activation of the fiber catalytically to form narrow micropore preferentially in carbon dioxide atmosphere. The narrow micropore volume of 0.3~0.4 cc/g, total pore volume of 0.3~0.8 cc/g, mean pore width of 0.5~0.7 nm was obtained in the range of 20~50% burnoff.

• 공업화학
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• 제17권3호
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• pp.310-316
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• 2006

본 연구에서는 수중 악취의 원인 물질인 용존 암모니아를 제거하기 위해 분말형태의 활성탄을 사용하였다. 특히, 일반적인 분말활성탄은 암모니아 흡착능이 좋지 않기 때문에 흡착능을 높이기 위해 분말활성탄의 표면을 산 용액으로 함침시킨 산 첨착활성탄을 제조하였다. 이렇게 제조한 산 첨착활성탄을 섬유 재질로 된 다공성 지지막($10{\sim}50{\mu}m$)의 표면에 압력에 의한 분리 활성 여과 층을 형성시켜 흡착과 분리를 동시에 할 수 있는 혼합 공정을 구성하였다. 그 결과 혼합공정에서 암모니아 제거율이 60% 이상 되어, 일반 분말활성탄에 비해 10~15% 더 높은 흡착능을 보였다. 그리고 층이 형성된 동적막의 순수투과성능 실험을 보면 수투과도는 400~700 LMH로 정밀여과(Microfiltration)막 수준의 역할을 한다. 이는 수처리에서 기존의 분리막 공정보다 고효율적인 처리 유량을 유지하는 효과가 기대된다.

• Carbon letters
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• 제11권2호
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• pp.131-136
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• 2010

Propellant waste was impregnated on the surface of activated carbon fiber and heat-treated at different temperature to introduce newly developed functional groups on the ACF surface. Functional groups of nitrogen and oxygen such as pyridine, pyridone, pyrrol, lacton and carboxyl were newly introduced on the surface of modified activated carbon fiber. The porosity, specific surface area, and morphology of those modified ACFs were changed as increasing the heat-treated temperature from 200 to $500^{\circ}C$. The optimum heat-treatment temperature was suggested to $500^{\circ}C$, because lower temperature given rise to the decrease of specific surface area and higher temperature resulted in the decrease of weight loss. Propellant waste can be used as an useful surface modifier to porous carbons.

• 대한환경공학회지
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• 제22권6호
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• pp.1037-1044
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• 2000

본 연구에서는 국내에서 쉽게 구할 수 있으며 탄화시 높은 강도를 가질 수 있는 참나무를 이용하여 생물 활성탄 공정(BAC)에 적합한 활성탄, 즉 흡착뿐만 아니라 미생물의 안식처로서의 역할을 할 수 있는 거대 세공이 많이 발달된 활성탄을 제조하는데 그 주안점을 두었다. 활성탄의 제조는 인산 침적에 의한 화학적 활성화법을 이용하여 제조하였고 제조된 활성탄의 요오드 흡착력(mg/g), 메틸렌 블루 탈색력(mg/g), B.E.T Method에 의한 비표면적($m^2/g$), 세공 크기 분포(Pore size distribution)를 분석하여 현재 생물 활성탄 공정에 많이 사용되고 있는 P사의 'picabiol' 활성탄과 비교하였다. 본 연구에서 사용된 화학적 활성화법의 주인자는 인산의 침적농도, 활성화 용도, 그리고 활성화 시간이다. 이중 활성화 시간은 예비 실험으로 3시간으로 고정시켰다. 최적 활성화 온도와 인산 첨적 농도를 찾기 위하여 활성화 온도는 $600^{\circ}C$에서 $800^{\circ}C$ 로 변화시켰으며 인산 침적 농도는 35wt%에서 50wt%로 변화시켰다. 이렇게 제조된 활성탄 중 $800^{\circ}C$에서 활성화시켰을 때 모든 인산 침적 농도에서 요오드 흡착력(1000~1100 mg/g)과 메틸렌 블루 탈색력(200~400 mg/g)으로서 가장 높은 효율의 활성탄을 얻을 수 있었으며 picabiol과 비교하여 보았을 때 비슷하거나 더 높은 효율의 활성탄을 제조할 수 있었다.

• Nuclear Engineering and Technology
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• 제53권5호
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• pp.1519-1523
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• 2021

Radioactive iodine (¹³¹I) released from nuclear power plants has been a critical environmental concern for workers. The effective trapping of radioactive iodine isotopes from the off-gas stream generated from nuclear facilities is an important issue in radioactive waste treatment systems evaluation. Numerous studies on retaining methyl iodide (CH₃I¹³¹) by impregnated activated carbons under the high content of moisture have been extensively studied so far. But there have been no good results on how to remove methyl iodide at high humid conditions up to now. A new challenge is to introduce other promising impregnating chemical agents that are able to uptake enough radioactive methyl iodide under high humid conditions. In order to develop a good removal efficiency to control radioiodine gas generated from a high humid process, activated carbons (ACs) impregnated with triethylene diamine (TEDA) and qinuclidine (QUID) were prepared. In addition, the removal efficiencies of the activated carbons (ACs) under humid conditions up to 95% RH were evaluated by applying the standard method specified in ASTM-D3808. Quinuclidine impregnated activated carbon showed a much higher decontamination factor above 1,000, which is enough to meet the regulation index for the iodine filters in nuclear power plants (NPPs).

• Carbon letters
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• 제1권3_4호
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• pp.178-190
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• 2001

• Environmental Engineering Research
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• 제19권3호
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• pp.289-292
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• 2014

The effect of carbon dioxide ($CO_2$) on global warming is serious problem. The adsorption with solid sorbents is one of the most appropriate options. In this study, the most interesting adsorbent is granular activated carbon (GAC). It is suitable material for $CO_2$ adsorption because of its simple availability, many specific surface area, and low-cost material. Afterwards, GAC was impregnated with chitosan solution as impregnated granular activated carbon (CGAC) in order to improve the adsorption capacity of GAC. This research aims to compare the physical and chemical characteristics of GAC and CGAC. The experiment was carried out to evaluate the efficiency of $CO_2$ adsorption between GAC and CGAC. The results indicated that the iodine number of GAC and CGAC was 137.17 and 120.30 mg/g, respectively. The Brunauer-Emmett-Teller results (BET) of both GAC and CGAC show that specific surface area was 301.9 and $531.3m^2/g$, respectively; total pore volume was 0.16 and $0.29cm^3/g$, respectively; and mean diameter of pore was 2.18 and 2.15 nm, respectively. Finally, the $CO_2$ adsorption results of both GAC and CGAC in single column how the maximum adsorption capacity was 0.17 and 0.25 mol/kg, respectively; how degeneration time was 49.6 and 80.0 min, respectively; and how the highest efficiency of $CO_2$ adsorption was 91.92% and 91.19%, respectively.