• Korean Membrane Journal
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• 제1권1호
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• pp.81-85
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• 1999

Tributyl phyosphate(TBP) polypropylene glycol 4000(PPG-4000) and the mixture of two compounds were examined as a liquid membrane in a supported liquid membrane (SLM) to separate phenol from aqueous solution.The feed concentration of phenol was varied in a broad range from 500 mg/L to 5000 mg/L and different types of liquid membrane were prepared to elucidate their effects on separation of phenol. It was found that the modified PPG 4000 with TBP and toluene diisocyanate(TDI) might be used as a proper liquid membrane because the mass transfer rate examined with this membrane was higher than that through methyl isobutyl ketone (MIBK) which has been used as a conventional solvent in a solvent extraction process. The breakthrough pressure of the SLM is defined to be the pressure difference across the membrane at which the supported liquid membrane is not kept in the pores any more. it indicates how the SLM is stable., It was found that the breakthrough pressure of the modified PPG-4000 was much higher than those of typical organic solvents.

• Carbon letters
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• 제15권3호
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• pp.203-209
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• 2014

The adsorption of volatile organic compounds (VOCs) was carried out using an activated carbon fiber (ACF) filter in an automobile. The adsorption capacities of formaldehyde, toluene, and benzene on an ACF filter were far better than those of a polypropylene (PP) mat filter and combined (PP+activated carbon) mat filter by batch adsorption in a gas bag. In a continuous flow of air containing toluene vapor through an ACF packed bed, the breakpoint time was very long, the length of the unused bed was short, and sharp "S" -type breakthrough curve was plotted soon after breakpoint, showing a narrow mass transfer zone of toluene on the ACF. The adsorption amount of toluene on the ACF filter was proportional to the specific surface area of the ACF; however, the development of mesopores 2-5 nm in size on the ACF was very effective with regard to the adsorption of toluene. The ACF air clarifier filter is strongly recommended to remove VOCs in newly produced automobiles.

• 공업화학
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• 제9권2호
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• pp.286-293
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• 1998

연소배가스로부터 $CO_2$를 선택적으로 분리하기 위한 활성탄 흡착공정 사용시 흡착능 향상을 위하여 $CO_2$와 친화력이 있는 화합물을 함침시키는 방법과 KOH를 함침시킨 후 고온에서 열처리하므로서 활성화시키는 방법이 사용되었다. 알칼리금속, 알칼리토금속, 또는 전이금속의 염화물을 함침시킨 활성탄에 대한 $CO_2$의 흡착량을 측정한 결과 함침 전의 활성탄의 흡착량보다 적었다. 이것은 함침되는 물질이 $CO_2$에 대한 친화력이 없이 단지 활성탄의 미세기공만 막는 결과임을 알 수 있었다. 알칼리금속수산화물 중 KOH를 함침시킨 활성탄에 대한 $CO_2$의 파과실험 결과 유입되는 기체에 수분이 있을 경우 흡착량이 증가했는데 이것은 KOH가 $CO_2$를 흡수하는 성질 때문이었다. 그러나 이 흡착제에 함친된 KOH가 $CO_2$와 반응하여 $K_2CO_3$로 변함에 따라 재현성이 없음을 알 수 있었다. KOH를 함침시킨 후 $800^{\circ}C$에서 열처리하여 활성화시킨 활성탄의 경우 함침된 KOH의 양이 증가할수록 $CO_2$의 흡착량이 증가했으며, KOH와 활성탄의 무게비(KOH/Activated-Carbon)가 4일 때 최대였다. 이 흡착제에 대해 온도별로 측정된 $CO_2$의 흡착량으로부터 Clausius-Clapeyron식을 이용하여 등량흡착열을 구했다. 그리고 고정층 파과실험을 통해 $CO_2$농도와 유속에 따른 파과특성을 살펴보았다.

• Korean Chemical Engineering Research
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• 제48권4호
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• pp.534-539
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• 2010

메탄 속에 포함되어 있는 TBM, THT, DMS 등의 유기 황 화합물에 대한 흡착 제거가 NaY와 CuNaY 제올라이트를 이용하여 303 K, 대기압 조건하에서 수행되었다. 삼성분계 흡착시스템 실험을 통해, NaY에서는 THT의 선택적 흡착이 목격되었으며, CuNaY에서는 모든 유기 황 화합물의 동시 흡착이 일어났다. 이러한 현상은 파과흡착곡선, 승온탈착, 겉보기 탈착 활성화 에너지 등의 실험결과로 부터 설명될 수 있었다. 황에 대한 흡착능은 CuNaY(2.90~3.20 mmol/g)가 NaY(0.70~0.90 mmol/g)보다 매우 우수하였다. 본 연구결과는 CuNaY에 존재하는 $Cu^{1+}$ 흡착점과 강한 산의 세기가 황 원자와의 강한 상호작용을 유발하여 높은 황 흡착능을 갖게 하는 것으로 이해된다.

• 상하수도학회지
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• 제21권3호
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• pp.323-329
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• 2007

There is no certain definition about advanced drinking water treatment but it is generally known as activated carbon process, membrane process or ozone process which can remove non-conventional pollutants such as taste and odor compounds, and micro-pollutants. There are more than 20 processes related to activated carbon as adsorber or biological activated carbon in Korea. The saturated carbon by pollutants can be reused by reactivation. However, the effect of reactivation on activated carbon is not well-understood in terms of changing physical properties of carbon to adsorption capacity of natural organic matter (NOM). In this study, the effects of reactivation on physical properties of activated carbon were investigated by isotherm and breakthrough of NOM. Ash content was increased from 8% to 13.3%. Iodine number is commonly used as an indicator for performance of reactivation. The iodine number was decreased about 20% after reactivating twice. The degree of reactivation can be evaluated by not only iodine number but also apparent density.

• 생물정신의학
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• 제1권1호
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• pp.40-59
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• 1994

The introduction of lithium salts for the treatment of mood disorder by Code in 1949 was a major therapeutic breakthrough. Yet it is far from the universal therpeutic agent in the treatment of mood disorders. Indeed, some acutely manic patients do not respond adeqately to lithium and some individuals experience breakthrough affective episodes during lithium maintenance. In the last decode, it has become c1ear that a significant number of patients with more highly recurrent disorders may require alternative or enhanced forms of prophylactic treatment. For these reasons, a variety of other drugs hove been employed for the treatment and prophylaxis of mood disorders. Efforts to develop new pharmacologic strategies for mood disorder hove included a diverse array of medications, ranging from potent benzodiazepines to novel neuroleptics and from anticonvulsants to calcium channel blockers. The anticonvulsants appear particularly useful in cases of dysphoric mania and rapid cycling state, subforms of bipolar disorder that respond quite poorly to conventional treatments. Among all of these new pharmacologic strategy, carbamazepine and sodium valproate have received the broadest clinical applications as maintenance therapies. The data documenting the short-term antimanic effectiveness of the calcium channel blocker verapamil and benzodiazepins such as clonazepam and lorazepam appear also promising. A number of other theoretically interesting, as well as clinically relevant therapies, which are not presently employed routinly, hove also been studied, including 2 blocker clonidine, atypical antipsychotic clozapine, cholinomimetics, 5-HT enhancers, thyroid and magnesium preparations. Now prophylaxis in mood disorder remains a considerable therapeutic challenge. Controlled testing of the prophylactic efficacy of compounds such as carbamazepine, valproic acid, and the calcium channel blockers represent important next step in the clinical trials for mood disorder.

• 한국산학기술학회논문지
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• 제12권6호
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• pp.2898-2903
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• 2011

휘발성 유기화합물인 저 농도의 MEK와 톨루엔을 사용하여 고정층 반응기에서 활성탄소섬유의 흡착 및 탈착특성을 조사하였다. 활성탄소섬유의 성능은 평형흡수량, 평형에 도달하는 시간, 그리고 탈착효율로 파악하였다. 다양한 실험을 통해 흡착공정에 있어 중요한 공정변수인 유입가스농도, 유량, 수분함량, 흡착제 주입량에 대한 영향을 연구하였다. 흡착층의 온도, 유량 그리고 유입가스농도가 증가할수록 파과시간이 감소하였다. 그리고 흡착제의 충전높이가 증가할수록 파과시간은 길어짐을 알 수 있었다. MEK와 톨루엔으로 흡착된 활성탄소섬유는 일정속도 가열과정을 통해 만족스럽게 재생되었으며 두 휘발성 유기화합물 중 MEK가 $150^{\circ}C$이하의 온도에서 훨씬 손쉽게 재생됨을 알 수 있었다.

• 한국환경과학회지
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• 제14권1호
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• pp.61-69
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• 2005

Adsorption characteristics of toluene vapor, which is one of important source of volatile organic compounds (VOCs), by activated carbon were investigated using a fixed bed adsorption column. The operating parameters such as breakthrough curve, adsorption capacity, mass transfer zone (MTZ), and length of unused bed (LUB) were studied. The experimental results showed that the breakthrough time decreased with increasing inlet toluene concentration and gas flow rate. MTZ and LUB increased with the increase of inlet concentration, gas flow rate, and particle size of activated carbon. The adsorption capacity increased with the increase of inlet toluene concentration, while it decreased with increasing particle size. However, it was kept at constant value regardless of the increase of gas flow rate. Adsorption isotherm of toluene vapor could be represented by the Freundlich adsorption equation fairly well. From the adsorption experiments using some VOC gases such as toluene, xylene, butyl acetate. butanol and acetone, it was also found that the adsorption capacity was higher in the case of gas with higher boiling point and lower vapor pressure.

• Bulletin of the Korean Chemical Society
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• 제27권1호
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• pp.77-81
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• 2006

The commercially available Amberlite XAD-2 and XAD-4 resins were modified with macrocyclic protoporphyrin IX (PPIX) or tetrakis(p-carboxyphenyl) porphyrin (TCPP) to enhance the adsorption capacity for phenol and chlorophenols. The chemically modified polymeric adsorbents (XAD-2+PPIX, XAD-2+TCPP, XAD-4+PPIX, and XAD-4+TCPP) were applied to the solid phase extraction as an adsorbent material for the preconcentration of phenol and chlorophenols in environmental waters. Generally, the synthesized adsorbents showed higher recoveries than underivatized adsorbents, XAD-2 and XAD-4, without matrix interferences. Especially, XAD-4+PPIX showed more than 90% recoveries for all compounds used in this study including hydrophilic phenol. The major factor for the increase of the adsorption capacity was the increase of $\pi$-$\pi$ interaction between adsorbents and samples due to the introduction of the porphyrin molecule. However, the breakthrough volumes and recovery values of the XADs+TCPP columns were slightly decreased for the bulky chlorophenols such as TCP and PCP. Using molecular mechanics methods, the structures of TCPP and PPIX were compared with that of porphine, the parent molecule of porphyrin. Four bulky p-carboxyphenyl groups of TCPP were torsional each other, thus the molecular plane of TCPP were not on the same level. In conclusion, the decrease of breakthrough volumes and recovery values of XADs+TCPP columns for bulky phenols can be explained by the steric hindrance of the $\pi$-$\pi$ interaction between porphyrin plane and the phenols.

• 공업화학
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• 제26권5호
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• pp.587-592
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• 2015

휘발성 유기화합물(Volatile organic compounds, VOCs) 중 톨루엔 가스의 흡착특성을 향상시키기 위하여 불소화 반응을 이용하여 활성탄소를 처리하였다. 이 활성탄소의 기공특성과 표면특성 평가를 위하여 비표면적 측정기와 X선광전자분광법(XPS)을 사용하여 분석하였고, 가스크로마토그래피를 이용하여 톨루엔 가스 흡착능과 제거효율을 고찰하였다. 100 ppm의 톨루엔 가스가 $300cm^3/min$으로 주입될 때, 불소화 처리된 활성탄소의 파과시간이 미처리 활성탄소에 비하여 약 27% 증가하였다. 0.1 g의 불소처리 활성탄소 흡착재는 19 h의 흡착시간 동안 100 ppm 농도의 톨루엔 가스를 모두 제거하였다. 이러한 실험 결과들은 톨루엔과 같은 발암성 물질을 제거하는 처리 기술로 활용될 수 있음을 보여주었다.