• 한국연초학회지
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• 제27권1호
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• pp.59-67
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• 2005

Activated carbon fiber (ACF) was surface modified by nitric acid to improve the adsorption efficiency of the propylamine. The adsorption amount of propylamine of the modified ACF increased $17\%$ more than that of as-received ACF. Desorption of propylamine from the propylamine saturated ACF was occurred in two steps, the first step started arround $50^{\circ}C$ showing the desorption of physically adsorbed propylamine and the second step started at $200^{\circ}C$ showing the decomposition of chemically adsorbed propylamine. Total desorption amount of propylamine from the modified ACF was larger than that of the as-received ACF because of increased functional groups. The oxygen and nitrogen contents on the modified ACF increased by 1.5 and 3 times compared with the as-received ACF. A part of propylamine adsorbed on ACF formed pyridine-like or pyrrolic structures with 2 carbons exposed on the surface of the ACF. It was found that propylamine reacted with strong or weak acidic functional groups such as -COOH or -OH existed on ACF surface.

• 한국환경과학회지
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• 제18권5호
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• pp.501-508
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• 2009

In this study, the characteristics of granular activated carbon (GAC) supported metal was investigated in an area influenced by flame discharge and temperature variation during irradiating microwave. The modified GAC was formulated by impregnating metal hydroxides of nickel (Ni/GAC), barium (Ba/GAC), copper (Cu/GAC), zinc (Zn/GAC), cobalt (Co/GAC) and lanthanum (La/GAC). Ba/GAC was selected as it showed lack of spark discharge and temperature increasing aspects. Comparison of adsorption and desorption amount of GAC and Ba/GAC showed that adsorption and desorption rate of the GAC were higher than those of Ba/GAC. The results show that the presence of barium can decrease adsorption/desorption rate because of plugging pore of GAC. Toluene regeneration rate of Ba/GAC was better than that of GAC due to barium loading. Finally, GAC with barium can be controled a rapid increasing temperature and spark discharge, increased the regeneration rate of toluene during desorption by irradiating microwave.

• 에너지공학
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• 제13권2호
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• pp.166-172
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• 2004

The activated carbon was produced from Sancheong bamboo by steam and carbon dioxide gas activation methods. The carbonization of raw material was conducted at 90$0^{\circ}C$ and gas activation reactions were conducted with respect to various conditions. -activation temperature 750-90$0^{\circ}C$, the flow rate of steam 0.5-2g-$H_2O$/g-char$.$hr, the flow rate of carbon dioxide 5-30$m\ell$-$CO_2$/g-char-min and activation time 1-5 hr. The prepared activated carbons were measured yield, the adsorption capacity of iodine and methylene blue, BET specific surface area and pore size distribution. The adsorption capacity of iodine (680.5-1526.1 mg/g) and methylene blue (18.3-221.5 mg/g) increased with creasing activation temperature and activation time. The adsorption capacity of iodine and methylene blue increased with the activation gas quantity in the range of 0.5-1.5g-$H_2O$/g-charㆍhr, 5-18.9$m\ell$-Co$_2$/g-charㆍmin. But those decreased over those range due to the pore shrinkage. The steam activation method was superior in efficiency to carbon dioxide activation method.

• 한국환경과학회지
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• 제24권9호
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• pp.1123-1129
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• 2015

This research was performed by means of several different virgin granular activated carbons (GAC) made of each coal, coconut and wood, and the GACs were investigated for an adsorption performance of iodine-131 in a continuous adsorption column. Breakthrough behavior was investigated that the breakthrough points of the virgin two coals-, coconut- and wood-based GACs were observed as bed volume (BV) 7080, BV 5640, BV 5064 and BV 3192, respectively. The experimental results of adsorption capacity (X/M) for iodine-127 showed that two coal- based GACs were highest (208.6 and $139.1{\mu}g/g$), the coconut-based GAC was intermediate ($86.5{\mu}g/g$) and the wood-based GAC was lowest ($54.5{\mu}g/g$). The X/M of the coal-based GACs was 2~4 times higher than the X/M of the coconut-based and wood-based GACs.

• Carbon letters
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• 제10권4호
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• pp.305-313
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• 2009

In this study, the adsorption of toxic pollutants onto cetyltrimethylammonium kaolin (CTAB-Kaolin) is investigated. The organo-kaolin is synthesized by exchanging cetyltrimethylammonium cations (CTAB) with inorganic ions on the surface of kaolin. The chemical analysis, the structural and textural properties of kaolin and CTAB-kaolin were investigated using elemental analysis, FTIR, SEM and adsorption of nitrogen at $-196^{\circ}C$. The kinetic adsorption and adsorption capacity of the organo-kaolin towards o-xylene, phenol and Cu(II) ion from aqueous solution was investigated. The kinetic adsorption data of o-xylene, phenol and Cu(II) are in agreement with a second order model. The equilibrium adsorption data were found to fit Langmuir equation. The uptake of o-xylene and phenol from their aqueous solution by kaolin, CTAB-kaolin and activated carbon proceed via physisorption. The removal of Cu(II) ion from water depends on the surface properties of the adsorbent. Onto kaolin, the Cu(II) ions are adsorbed through cation exchange with $Na^+$. For CTAB-kaolin, Cu(II) ions are mainly adsorbed via electrostatic attraction with the counter ions in the electric double layer ($Br^-$), via ion pairing, Cu(II) ions removal by the activated carbon is probably related to the carbon-oxygen groups particularly those of acid type. The adsorption capacities of CTAB-kaolin for the investigated adsorbates are considerably higher compared with those of unmodified kaolin. However, the adsorption capacities of the activated carbons are by far higher than those determined for CTAB-kaolin.

• 한국세라믹학회지
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• 제44권11호
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• pp.607-612
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• 2007

Zn-AC and Zn-H-AC series prepared from non- and surface-modified activated carbon were investigated in terms of their hydrogen production capacity. An increase in the concentration of the zinc salts used with these series was shown to lead to a decrease in the values of the surface textural properties. The existence of zinc complexes on the surface was confirmed from an analysis of XRD data. The SEM micrographs of the two different sample types showed that the transformation of the carbon surface with an acid pre-treatment significantly change the metal contents on the surfaces of the carbon matrix. The EDX spectra indicated that all of the samples were richer in the amount of oxygen and zinc compared to any other elements. The results obtained using the Boehm's titration method showed that the positive introduction of the acidic groups on the carbon surfaces with the acid treatment is correlated with an increase in the amounts of zinc complexes with variation of the acidic groups. In terms of the hydrogen production performance, the volume fractions of the Zn-H-AC series were found to produce higher amounts than the Zn-AC series as a function of the metal contents considering the effects of the acid treatment.

• 분석과학
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• 제18권2호
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• pp.154-162
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• 2005

최근 국내 일부 정수장에서 검출된 것으로 보도되어진 바 있어 우리나라의 하천 수의 오염이 우려되고 있고, 일부 오염정도가 높은 하천수의 정화과정에서 제거가 완전히 이루어지지 않는 것으로 사료되는 1,4-dioxane은 그 독성과 음용수의 섭취량을 고려할 때 음용수 섭취로 인한 인체효과가 문제화 될 것으로 판단된다. 따라서 본 연구에서는 활성탄과 멤브레인으로 구성된 다단계 필터시스템에서 음용수 중에 존재하는 1,4-dioxane에 대한 제거효과에 대하여 연구하였다. 확인방법은 MTBE을 이용한 액체-액체 추출방법을 사용하였으며 제거실험은 압력별 필터단계별로 30 L마다 300 L 까지 실시하였다. 그 결과 초기에는 1차 활성탄 필터이후 70% 이상의 제거효과를 나타내었으며 멤브레인 이후 95%이상 그리고 2차 활성탄 이후 100% 제거되는 결과를 나타내었다. 그러나 통수량이 증가할수록 각 단계별 제거율은 점차 감소하였으며 300 L 통수 후 1차 활성탄에서 30%, 멤브레인 이후 88% 그리고 최종 활성탄 이후 99%의 제거율을 나타내었다.

• 분석과학
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• 제18권5호
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• pp.436-443
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• 2005

활성탄 미분을 용액계에 분산하므로 수반 되는 결과를 고찰하기 위하여 칼륨처리 미분 활성탄의 물리적 성질과 그들에 응용에 대한 연구를 수행하였다. 오염수로부터 오염물질의 촉매적 제거 효율을 연구하기 위하여 분산매로써 두 종류의 칼륨 미분 활성탄을 사용하였다. 칼륨염을 포함하는 수용액내에서 처리된 활성탄 시료로부터 얻어진 표면 특성화를 위하여, 흡착 등온곡선 형태, SEM, EDX 및 표면 기능기 변화 등을 주된 연구 대상으로 하였다. pH 변화에 따른 칼륨 미분 활성탄을 오염수에 분산하여 색도, COD, T-N 및 T-P 등에 대하여 제거 효율을 연구하였다. 칼륨 미분 활성탄을 처리한 오염수에 대한 네 가지 요소 제거 결과로부터, pH 6~8의 범위에서 만족할 만한 제거 효율이 얻어 졌다. 본 연구로부터 칼륨 처리 미분 활성탄의 분산에 의한 오염물질의 제거 효율이 흡착 특성 및 촉매적 효율에 의하여 입증되었다.

• 분석과학
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• 제12권2호
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• pp.105-110
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• 1999

금속이 처리된 활성탄에 대한 물리 화학적 흡착특성과 항균효과에 대한 연구를 하였다. Cd 및 Cu가 처리된 활성탄에 관한 물리 흡착 연구로부터 대표적인 Type I의 등온곡선을 얻었다. 이들 금속이 처리된 활성탄의 BET 비표면적 값은 Cd-AC의 경우 $1101-1418m^2/g$의 사이에 분포하였으며, Cu-AC의 경우 $1084-1361m^2/g$의 범위에 분포하였다. 또한 흡착 등온곡선으로부터 ${\alpha}_s$-방법을 도입하여 미세 동공 부피 값과 대표적인 동공 크기 분포를 얻었다. SEM 연구로부터 활성탄의 많은 미세 동공들이 처리된 금속에 의하여 가리움 현상을 일으키는 것으로 나타났다. Escherichia coli에 대한 항균효과를 알아보기 위한 결과로부터 Cd와 Cu의 양을 증가시켜 처리함에 따라 항균 활성 면적이 증가함을 알 수 있었다.

• Korean Chemical Engineering Research
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• 제46권6호
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• pp.1130-1134
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• 2008

아세트산은 테레프탈산 제조 공정에서 용매로 사용되며, 사용된 아세트산은 반응 후 증류 공정을 통하여 분리 회수된다. 그러나 소량의 아세트산은 그대로 폐수에 유입되어 버려지는데, 흡착공정을 이용하면 소량의 아세트산을 회수하여 다시 재사용할 수 있다. 본 연구에서는 활성탄을 아세트산 흡착제로 활용하여 상용활성탄의 아세트산 흡착능과 흡착능에 대한 온도 및 흡착제 산처리 효과를 살펴보았다. 활성탄의 아세트산 흡착능은 흡착 키네틱 실험으로 관찰한 결과, 303 K에서는 0.176 mmol/g의 흡착능을 보였으나, 343 K에서는 0.118 mmol/g으로 흡착능이 떨어졌다. 즉, 온도가 증가하면 활성탄의 아세트산 흡착능은 감소하는 결과가 나타났다. 산처리실험에서는 활성탄 표면을 염산 혹은 옥살산으로 처리할 경우, 활성탄의 아세트산 흡착능이 소폭 증가하였다. 이는 산처리로 인해 활성탄 표면에 카르복실산, 혹은 페놀 수산화기 등 표면 관능기가 증가하였기 때문인 것으로 보인다. 아세트산 탈착 실험에서는 정량분석결과, 흡착된 아세트산의 89% 정도가 탈착되었다.