• 한국지하수토양환경학회지:지하수토양환경
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• 제13권3호
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• pp.52-58
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• 2008

여러 조건으로 제조한 망간첨착활성탄(Mn-AC)을 유기물과 무기물이 함께 오염되어 있는 합성 폐수처리에 적용하였다. 유기물과 무기물의 대표물질로 각각 페놀과 3가 비소를 선정하였다. Mn-AC의 물리화학적 특성과 안정성을 분석한 후, 회분식 반응조에서 활성탄(AC) 및 Mn-AC에 의한 3가 비소 및 페놀 흡착 특성을 조사하였다. Mn-AC의 안정성 평가를 위해 pH 2에서 4의 산성용액에서 용출되는 망간의 농도로부터 평가하였다. pH 3 이하에서는 Mn-AC로부터 많은 양의 망간이 용출되었지만, pH 4에서는 청정지역 허용기준인 3 ppm 이하의 농도로 용출되었다. Mn-AC에 대한 X-선 회절기 분석결과 첨착된 망간은 $Mn_2O_3$로 밝혀졌다. Mn-AC를 이용한 3가 비소와 페놀의 동시처리 실험결과 3가 비소는 낮은 pH에서 AC보다 높은 산화율을 보였으나, 중성 이상의 pH에서는 AC가 더욱 높은 산화율을 보였다. 활성탄에 망간을 첨착시킴으로서, 비표면적이 13% 감소하였고 이로서 Mn-AC에 의한 페놀제거율은 AC에 비해 8% 정도 줄어들었다. 3가 비소 산화 및 페놀 흡착실험을 통하여 Mn-AC는 복합오염물을 갖는 폐수의 동시처리에 적용될 수 있음을 알 수 있었다.

• Carbon letters
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• 제19권
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• pp.12-22
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• 2016

Date palm leaflets were used as a precursor to prepare dehydrated carbon (DC) via phosphoric acid treatment at 150℃. DC, acidified with H₃PO₄, was converted to activated carbon (AC) at 500℃ under a nitrogen atmosphere. DC shows very low surface area (6.1 m²/g) while AC possesses very high surface area (829 m²/g). The removal of lisinopril (LIS) and chlorpheniramine (CP) from an aqueous solution was tested at different pH, contact time, concentration, and temperature on both carbons. The optimal initial pH for LIS removal was 4.0 and 5.0 for DC and AC, respectively. However, for CP, initial pH 9.0 showed maximum adsorption on both carbons. Adsorption kinetics showed faster removal on AC than DC with adsorption data closely following the pseudo second order kinetic model. Adsorption increases with temperature (25℃–45℃) and activation energy (E_a) is in a range of 19–25 kJ mol/L. Equilibrium studies show higher adsorption on AC than DC. Thermodynamic parameters show that drug removal is endothermic and spontaneous with physical adsorption dominating the adsorption process. Column adsorption data show good fitting to the Thomas model. Despite its very low surface area, DC shows ~70% of AC drug adsorption capacity in addition of being inexpensive and easily prepared.

• Journal of the Korean Wood Science and Technology
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• 제50권4호
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• pp.256-271
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• 2022

Activated carbon (AC) derived from coconut shells (CS-AC) was obtained through pyrolysis at 700℃ and subsequently activated with H₃PO₄. AC was ground in a Wiley mill several times to form powder particles at particle scales of 80, 100, and 200 meshes. The characterization of the AC was studied using scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FT-IR), and surface area analysis (S_BET). The CS-AC-200 mesh resulted in a higher percentage of mesopores and surface area. This particle size had a larger surface area with angular, irregular, and crushed shapes in the SEM view. The smaller particles had smoother surfaces, less wear, and increased curing depth and ratio of the hardness of the resin composite. Based on the characterization results of the AC, it is evident that CS-AC with a 200 mesh particle size has the potential to be used as a filler in biocomposites.

• Carbon letters
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• 제14권2호
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• pp.126-130
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• 2013

In this study, we present a more electrochemically enhanced electrode using activated carbon (AC)-sulfur (S) composite materials, which have high current density. The morphological and micro-structure properties were investigated by transmission electron microscopy. Quantity of sulfur was measured by thermogravimetric analysis analysis. The electrochemical behaviors were investigated by cyclic voltammetry. As a trapping carbon structure, AC could provide a porous structure for containing sulfur. We were able to confirm that the AC-S composite electrode had superior electrochemical activity.

• 한국물환경학회지
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• 제22권2호
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• pp.328-332
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• 2006

Fe(III)-impregnated activated carbon (Fe-AC) was applied in the treatment of synthetic wastewater containing Cu(II). To investigate the stability of Fe-AC at acidic condition, dissolution of Fe was studied with a variation of solution pH ranging from 2 to 4. Fe-AC was unstable at pH 2, showing a gradual increase of the dissoluted Fe as reaction time increased, while negligible amount of Fe was dissoluted above pH 3. This stability test suggests the applicability of Fe-AC in the treatment of wastewater above pH 3. Adsorption capacity of Cu(II) onto activated carbon (AC) and Fe-AC was investigated in a batch and a column test. In the adsorption kinetics, rapid adsorption of Cu(II) onto AC and Fe-AC was noted at initial reaction time and then reached a near complete equilibrium after 6 hrs. Adsorption trends of Cu(II) onto AC and Fe-AC were similar, showing an increased Cu(II) adsorption at higher pH. Compared with AC, Fe-AC showed a greater Cu(II) adsorption over the entire pH range studied in this research. From the adsorption isotherm obtained with variation of the concentration of Cu(II), the maximum adsorption capacity was identified as 61,700 mg/kg.

• Carbon letters
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• 제16권1호
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• pp.45-50
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• 2015

High crystallinity coke-based activated carbon (hc-AC) is prepared using a potassium hydroxide solution to adsorb carbon dioxide ($CO_2$). The $CO_2$ adsorption characteristics of the prepared hc-AC are investigated at different temperatures. The X-ray diffraction patterns indicate that pitch-based cokes prepared under high temperature and pressure have a high crystal structure. The textural properties of hc-AC indicate that it consists mainly of slit-like pores. Compared to other textural forms of AC that have higher pore volumes, this slit-pore-shaped hc-AC exhibits higher $CO_2$ adsorption due to the similar shape between its pores and $CO_2$ molecules. Additionally, in these high-crystallinity cokes, the main factor affecting $CO_2$ adsorption at lower temperature is the pore structure, whereas the presence of oxygen functional groups on the surface has a greater impact on $CO_2$ adsorption at higher temperature.

• 대한환경공학회지
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• 제37권3호
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• pp.175-181
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• 2015

이산화탄소 포집을 위한 기능성 흡착제인 폴리에틸렌이민(PEI)을 함침한 활성탄을 평가하였다. 이산화탄소 흡착제의 흡착 특성은 GC/TCD, BET 표면적 및 FT-IR을 사용하였다. 활성탄에 PEI를 10, 30, 50 wt%를 함침하여 흡착제를 합성하고, 온도변화에 따른 이산화탄소의 흡착능을 조사하였다. $20^{\circ}C$와 $100^{\circ}C$에서의 이산화탄소 흡착능은 다음과 같다: $20^{\circ}C$에서는 AC > PEI(10)-AC > PEI(30)-AC > PEI(50)-AC의 순으로 나타났으며, $100^{\circ}C$에서는 PEI(10)-AC > PEI(30)-AC > PEI(50)-AC > AC 순으로 나타났다. 아민 기능기의 활성탄의 흡착능이 순수 활성탄보다 아미노기에 의하여 화학 흡착 때문에 높은 온도에서 높게 나타났다. 본 연구의 결과로 PEI(10) 활성탄은 고온의 가스로부터 이산화탄소 포집에 가장 유능한 흡착제 중 하나로 보여진다.

• 공업화학
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• 제31권5호
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• pp.552-559
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• 2020

Activated carbon-nickel (II) oxide (AC-NiO) electrodes were studied as materials for the capacitive deionization (CDI) of aqueous sodium chloride solution. AC-NiO electrodes were fabricated through physical mixing and low-temperature heating of precursor materials. The amount of NiO in the electrodes was varied and its effect on the deionization performance was investigated using a single-pass mode CDI setup. The pure activated carbon electrode showed the highest specific surface area among the electrodes. However, the AC-NiO electrode with approximately 10 and 20% of NiO displayed better deionization performance. The addition of a dielectric material like NiO to the carbon material resulted in the enhancement of the electric field, which eventually led to an improved deionization performance. Among all as-prepared electrodes, the AC-NiO electrode with approximately 10% of NiO gave the highest salt adsorption capacity and charge efficiency, which are equal to 7.46 mg/g and 90.1%, respectively. This finding can be attributed to the optimum enhancement of the physical and chemical characteristics of the electrode brought by the addition of the appropriate amount of NiO.

• 한국재료학회지
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• 제25권4호
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• pp.191-195
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• 2015

To improve its textural properties as a support for platinum catalyst, carbon aerogel was chemically activated with KOH as a chemical agent. Carbon-supported platinum catalyst was subsequently prepared using the prepared carbon supports(carbon aerogel(CA), activated carbon aerogel(ACA), and commercial activated carbon(AC)) by an incipient wetness impregnation. The prepared carbon-supported platinum catalysts were applied to decalin dehydrogenation for hydrogen production. Both initial hydrogen evolution rate and total hydrogen evolution amount were increased in the order of Pt/CA < Pt/AC < Pt/ACA. This means that the chemical activation process served to improve the catalytic activity of carbon-supported platinum catalyst in this reaction. The high surface area and the well-developed mesoporous structure of activated carbon aerogel obtained from the activation process facilitated the high dispersion of platinum in the Pt/ACA catalyst. Therefore, it is concluded that the enhanced catalytic activity of Pt/ACA catalyst in decalin dehydrogenation was due to the high platinum surface area that originated from the high dispersion of platinum.

• 공업화학
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• 제23권5호
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• pp.490-495
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• 2012

오존/활성탄 공정을 이용하여 페놀을 처리 할 경우, 활성탄에 의해 나타나는 촉매효과에 관한 연구를 수행하였다. 오존 단독공정에 활성탄을 추가할 경우, 활성탄 투입량이 증가할수록 용존 오존 및 페놀의 분해효율이 증가하는 것으로 나타났다. 이는 활성탄에 의해서 용존 오존이 분해되어 생성된 수산화 라디칼이 페놀 제거에 영향을 미쳤으며, 본 연구에서는 활성탄의 촉매효과([$\Delta$phenol] / $[{\Delta}O_{3}]_{AC}$)로 나타내었다. 활성탄 10~40 g/L 투입 시, 모든 활성탄의 최대 촉매효과 값은 $2.0\;{\pm}\;0.1$로 나타났지만, 10 g/L와 20 g/L를 투입한 경우, 40 min 경과 후 최대 촉매효과에 근접한 반면, 활성탄 30 g/L와 40 g/L를 투입한 경우, 반응 20 min 경과 후 최대 촉매효과에 도달하였다. 또한 Total Organic Carbon (TOC, 총유기탄소)의 제거율은 오존 단독공정에서 0.23으로 나타났으며, 오존/활성탄 공정에서는 0.63으로 나타났다.