• 상하수도학회지
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• 제11권2호
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• pp.76-93
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• 1997

Activated carbon is widely used for the treatment of water, wastewater and other liquid wastes. Biological activated carbon (BAC) process is water and wastewater treatment process developed in the 1970's. In addition to activated carbon adsorption, biodegradation organic pollutants occurs in the BAC bed where a large amount of aerobic biomass grows. This results in a long operation time of the carbon before having to be regenerated and thus a low treatment cost. Although the BAC process has been widely used, its mechanisms have not been well understood, especially the relationship between biodegradation and carbon adsorption, whether these two reactions can promote each other or whether they just simultaneously exist in the BAC bed. Also, the phenomenon of bioregeneration has been confused that previously occupied adsorption sites appear to be made available through the actions of microorganisms. And that, because biological process is influenced by low temperature, the mechanism of the BAC process is also effected by temperature variation in our country of winter temperature near the freezing point. Therefore, the objective of this study examines closely the mechanism of the BAC process by temperature variation using phenol as substrate. From this study, biological activated carbon is good substrate removal better than non adsorbing materials (charcoal, sand) as temperature variation, especially low temperature(near $5^{\circ}C$).

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.730-733
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• 2001

Separation of PET and PVC is a key technology to achieve effective plastics recycling but no efficient and economically feasible method has been developed yet. The application of flotation was investigated by many researchers but the causes of the selectivity were not clarified. This paper described the adsorption mechanism of wetting agents onto plastics, using the agents which have various polarity and hydrocarbon chain length. It was found that (1) hydrophobic interaction played a predominant role for the adsorption, (2) anionic wetting agents could be adsorbed onto negatively charged plastics with the polar radicals oriented outer part of the plastics, then often depressed plastics more effectively than cationic agents, and (3) PET and PVC could be separated with dodecyamine hydrochloride and sodium dodecyl- sulfonate in the concentration ranges of 1.0$\times$10$^{[-10]}$ $^{6}$ -5.0$\times$10$^{[-10]}$ $^{5}$ and 2.0$\times$10$^{[-10]}$ $^{6}$ -1.0$\times$10$^{[-10]}$ $^{5}$ mo1/1, respectively.

• Korean Chemical Engineering Research
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• 제58권3호
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• pp.458-465
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• 2020

활성탄에 의한 acid fuchsin (AF) 염료의 흡착에 대한 등온선, 동력학 및 열역학적 특성치를 흡착제의 양, pH, 초기 농도, 접촉시간 및 온도를 변수로 하여 수행하였다. 활성탄을 사용한 AF의 흡착에 대한 pH의 영향은 산성(pH 8)에서 흡착백분율이 높은 욕조 현상을 나타냈다. 등온흡착 데이터는 Freundlich, Langmuir, Dubinin-Radushkevich 등온흡착식에 맞춰 보았다. Freundlich 식이 가장 높은 일치도를 나타냈으며, 흡착메카니즘이 다분자층 흡착임을 알았다. 흡착용량은 온도증가와 함께 증가하였다. Freundlich의 분리계수는 이 흡착공정이 적합한 처리공정임을 나타냈다. Dubinin-Radushkevich 등온흡착식에 의해 평가된 흡착 에너지는 활성탄에 의한 AF의 흡착이 물리 흡착임을 확인시켰다. 흡착동력학은 유사이차반응속도식에 잘 맞았다. 입자내 확산 모델에 의해 흡착점에서의 표면 확산이 율속단계로 평가되었다. 흡착공정의 활성화 에너지와 엔탈피 변화는 각각 21.19 kJ/mol, 23.05 kJ/mol 이었다. Gibbs 자유 에너지 변화는 흡착반응이 온도가 높아질수록 자발성이 더 진다는 것을 알려주었다. 양의 엔트로피는 이공정이 비가역적이라는 것을 나타냈다. 등량 흡착열은 본질덕으로 물리흡착임을 나타냈다.

• 한국환경과학회지
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• 제20권2호
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• pp.241-249
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• 2011

In this research, equilibrium of adsorption and kinetics of As(V) removal were investigated. The coal mine drainage sludge(CMDS) was used as adsorbent. To find out the physical and chemical properties of CMDS, XRD (X-ray diffraction), XRF (X-ray fluorescence spectrometer) analysis were carried out. The CMDS was consist of 70% of goethite and 30% of calcite. From the results, an adsorption mechanism of As(V) with CMDS was dominated by iron oxides. Langmuir adsorption isotherm model was fitted well more than Freundlich isotherm adsorption model. Adsorption capacities of CMDS 1 was not different with CMDS 2 on aspect of amounts of arsenic adsorbed. The maximum adsorption amount of two CMDS were respectively 40.816, 39.682 mg/g. However, the kinetic of two CMDS was different. The kinetic was followed pseudo second order model than pseudo first order model. Concentrations of arsenic in all segments of the polymer in CMDS 2 does not have a constant value, but the rate was greater than the value of CMDS 1. Therefore, CMDS 2, which is containing polymer, is more effective for adsorbent to remove As(V).

• 한국대기환경학회지
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• 제3권1호
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• pp.41-46
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• 1987

Adsorption and reaction studies were made for the catalytic oxidation in aqueous slurries of activated carbon at room temperature and atmospheric pressure. In order to analyze the reaction rate, the mechanism was assumed by the steps of nonhomogeneous catalytic reaction. The experimental result show that oxidation rate was controlled by the reaction between adsorbed molecular oxygen and sulfur dioxide on the catalyst surface. Ar room temperature, the equat5ion of reaction rate was given as $ro_2 = 2.49 \times 10^{-7} P_O_2^{0.604}$.

• 대한전자공학회논문지
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• 제26권10호
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• pp.1528-1534
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• 1989

Photoeffects at the p-GaP semiconductor/CsNO3 electrolyte interface were investigated in terms of their current-voltage characteristics. The photoeffects at the semiconductor-electrolyte interfaces and their photocurrent variations are verified using Ar ion laser and continuous cyclic voltammetric methods. The mechanism of charge transfer at the photogeneration in the depletion layer rather than the photodecomposition of the p-GaP semiconductor electrode surface and/or the water photoelectrolysis. The adsorption of Cs+ ions at the interface is physical adsorption.

• 상하수도학회지
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• 제11권4호
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• pp.71-79
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• 1997

Biological Activated Carbon (BAC) process is widely used for the advanced water treatment, but it's mechanisms have not been well understood, especially the relationship between biodegradation and carbon adsorption. Also the phenomenon of bioregeneration has been confused that previously occupied adsorption sites appear to be made available through the actions of microorganisms. Therefore, the objectives of this study examines closely the mechanism of bioregeneration by temperature variation, especially low temperature.

• Bulletin of the Korean Chemical Society
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• 제16권2호
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• pp.130-134
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• 1995

Surface-enhanced Raman (SER) scattering of 2-cyanonaphthalene (2-CN) has been investigated in silver sol. Addition of halide ions was needed to obtain authentic SER spectra of the molecule. The SER spectra thus obtained exhibited a slight but noticeable dependence on the kind of halide ions used. This halide-dependent spectral variation was attributed to the orientational change of molecule on silver sol surface. A possible mechanism for such an orientational change is proposed in terms of the competitive adsorption of 2-CN with halide ions on the so-called halide-specific sites.

• 한국표면공학회지
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• 제27권6호
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• pp.335-339
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• 1994

The underpotential deposition of zinc was investigated on carbon steel and nickel. The relationship be-tween the deposition potentials and the corresponding amounts of charge for deposited layers shows a very similar trend to the multilayer adsorption mechanism. The experimental results fit a mathematical model de-rived on the basis of the BET equation for the underpotential deposition.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.291-294
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• 2006

Studies of the effectiveness of anthraquinone (AQ) in kraft-AQ pulping in terms of its mechanism of mass transfer have been conducted. Experiments performed have demonstrated an 'apparent solubility' of AQ in caustic solutions of wood lignin. The adsorption behavior of AQ species was also analyzed. Anthraquinone-2-sulfonic acid (AQ-S), a water-soluble derivative of AQ, showed selective adsorption on wood. A mechanism for the transport of AQ into wood chips during kraft pulping are proposed, and some explanations for previously unexplained observations are addressed.