• Title/Summary/Keyword: 등온성

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석회계 고화재에 대한 중금속의 흡착 반응에서의 등온식의 적용성

  • 류정훈;김용인;박정순;장연수
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2001.09a
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    • pp.180-183
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    • 2001
  • 오염물 이동에 영향을 미치는 지연계수는 용질과 시료의 흡착특성을 나타낸다. 흡착특성을 표현하는 데에는 Freundlich등온식, Langmuir등온식 또는 선형등온식등을 사용할 수 있는 데, 본 연구에서는 상관계수를 이용하여 각등온식의 적용성을 평가하고 용질이동 수치해 석을 하여 농도가 10ppm 이하로 낮을 경우의 용질이동정도를 상호 비교하였다. 아연, 크롬, 납에 대한 등온식의 상관계수에 따른 적용성 평가결과 Freundlich 등온식이 보편적으로 적용 가능한 것으로 나타났고, 수치해석 결과 농도가 10ppm 이하일 경우는 용질이동성이 동일하게 나타났다.

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Applicability of Theoretical Adsorption Models for Studies on Adsorption Properties of Adsorbents(1) (흡착제의 흡착특성 규명을 위한 흡착모델의 적용성 평가(1)-흡착등온식을 이용한 평가)

  • Na, Choon-Ki;Han, Moo-Young;Park, Hyun-Ju
    • Journal of Korean Society of Environmental Engineers
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    • v.33 no.8
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    • pp.606-616
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    • 2011
  • The objectives of this study were to evaluate the applicability of adsorption models for adsorption properties of adsorbents. For this study, adsorption experiment of $NO_3^-$ ion using anion exchange resin has been investigated under adsorption equilibrium and kinetic in bach process. Adsorption equilibrium experiment were carried out that two conditions is change of adsorbate concentration and change of adsorbent weight. Experiment results have been analyzed by adsorption isotherm models, energy models and kinetic models. Under the condition of change of adsorbate concentration was best described by Sips and Redlich-Perterson isotherm models. However case of change of adsorbent weight was described by Langmuir isotherm models. It seems reasonable to assume that isotherm model was dominated by multiple mechanism according to experiment condition.

Modeling for isothermal bianite transformation in low alloy steels (저합금강의 베이나이트 등온 변태 거동 예측 모델링)

  • 엄상호;문준오;이창희;윤지현;이봉상
    • Proceedings of the KWS Conference
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    • 2004.05a
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    • pp.194-196
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    • 2004
  • 최근 구조용 강재의 제조 및 적용에 있어 기계적 성질 제어의 필요성이 증가하고 있으며, 이는 공정 중의 미세조직 변화의 예측을 필요로 한다. 이에 상변태 현상에 대한 다양한 모델이 제안되고 있으며, 특히 등온 변태 모델과 비 등온 과정을 미소의 등온구간의 합으로 가정한 가산법칙의 적용을 기본으로 하고 있다. (중략)

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Altered Langmuir Adsorption Isotherm under the Consideration of the Displacement of Water Molecules with Adsorbate Ion at the Surface of Adsorbent (흡착제(吸着劑) 표면(表面)에서의 흡착질(吸着質)과 물분자(分子)의 치환(置換)을 고려(考慮)한 수정(修正) Langmuir 등온흡착식(等溫吸着式))

  • Kim, Dong-Su
    • Resources Recycling
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    • v.15 no.3 s.71
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    • pp.81-86
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    • 2006
  • Altered Langmuir adsorption isotherm has been suggested for adsorption reactions occurring in aqueous environment based upon the concept of the steric displacement between adsorbates and water molecules at the surface of adsorbent. For the adsorption of $Cd^{2+}$ on activated carbon, the suggested adsorption isotherm was shown to be more well applied to the experimental results compared with the classical Langmuir adsorption isotherm. Based on this, regarding the adsorption system which following the Langmuir model more precise design and controllable operation of the process were considered to be attainable when the adsorption process is analyzed employing the altered adsorption isotherm.

Adsorption isotherm on the heterogeneous surface with spatially uneven periodic adsorption heat distribution (요철형 공간주기성을 갖는 Heterogeneous 표면 흡착열분포에 대한 흡착등온식)

  • 김철호;황보승
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.12 no.3
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    • pp.115-119
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    • 2002
  • An adsorption isotherm on the heterogeneous surface which has spatially periodic adsorption heat distribution was formalized. Usefulness of the formalized adsorption isotherm is discussed with the help of a model calculation. Statistical thermodynamics is used throughout.

Adsorption Characteristics of Elemental Iodine and Methyl Iodide on Base and TEDA Impregnated Carbon (활성탄을 이용한 원소요오드 및 유기요오드 흡착특성)

  • Lee, Hoo-Kun;Park, Geun-Il
    • Nuclear Engineering and Technology
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    • v.28 no.1
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    • pp.44-55
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    • 1996
  • For the purpose of controlling the release of radioiodine to the environment in nuclear power plants, adsorption characteristics of elemental iodine and methyl iodide on the base carbon and 2%, 5% TEDA impregnated carbons were studied. The amounts of adsorption of elemental iodine and methyl iodide on the carbons were compared with Langmuir, Freundlich, Sips and Dubinin-Astakhov(DA) isotherm equations. Adsorption data were well correlated by the DA equation based on the potential theory. Adsorption energy distributions were obtained from the parameters of the DA equation derived from the condensation approach method. For the adsorption of methyl iodide and elemental iodine-carbon system, the DA equation can be well expressed by the degree of heterogeneity of the micropore system because the surface is nonuniform when its potential energy is unequal. The adsorption energy distribution wes investigated to find a surface heterogeneity on the carbon. The surface heterogeneity for iodine-carbon system is highly affected by the adsorbate-adsorbent interaction as well as the pore structure. The surface heterogeneity increases as a content of TEDA impregnated increases. The adsorption nature of methyl iodide on carbon turned out to be more heterogeneous than that of elemental iodine.

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Removal of phosphorus from solution using bark with polyallylamine hydrochloride (Polyallylamine hydrochloride로 처리한 수피를 이용한 수용액상의 인 제거)

  • Yang, Kyung-Min;Kim, Ha-Na;Kim, Yeong-Kwan
    • Journal of Industrial Technology
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    • v.27 no.A
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    • pp.203-209
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    • 2007
  • 본 연구는 목재로서 활용가치가 적은 수피(bark)를 활용하여 수질오염물질을 제거할 수 있는 여과 시스템에 대한 기초연구로서 소나무의 일종인 loblolly pine(Pinus taeda L.) 수피의 인 ($PO_4-P$) 흡착특성을 연구하였다. 실험에 사용된 수피는 입상형태로서 polyallylamine hydrochloride로 전처리하여 회분식 등온 흡착실험을 수행하였다. 회분식 등온흡착실험은 수용액 pH 3~pH 8범위에서, 인의 농도별(10, 20, 30, 40 mg/L)로 수행하였다. pH 5에서 가장 높은 인 제거 효율을 나타냈으며, 수용액의 pH는 실험 후 pH 3으로 감소하였다. 이러한 감소는 수피에 의한 phosphate의 흡착이 Lewis acid-base 반응으로서 이 과정에서 $H^+$의 방출로 인하여 나타난 현상인 것으로 여겨지며, 주된 반응 메카니즘은 더 연구할 필요성이 있다. 인 흡착은 초기에 빠른 속도로 진행되었으며 대략 200분 이후에 평형에 도달하였고, 시간이 지날수록 흡착양이 증가하는 경향을 보였다. 인의 흡착특성 결과는 Langmuir 등온흡착식과 Freundlich 등온흡착식으로 설명될 수 있으며, 등온흡착식 적용결과, 흡착제에 대한 최대 흡착능은 7.14 mg/g 이며 다른 흡착제와 비교하여 더 높았다. 실험결과와 모델에 의한 흡착능을 비교하고자 pseudo second-order model을 적용하여 흡착 동역학 상수를 구하였다. 또한 EDXA분석으로 회분식 흡착실험 후 수피와 인이 결합되어있는 것을 확인할 수 있었다.

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Prediction of Gas Phase Sorption Isotherms on The Basis of QSAR Method (QSAR 방법을 이용한 가스 상태의 등온흡착선 예측)

  • Kim, Jong O
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.11 no.3
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    • pp.11-18
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    • 1991
  • Volatile organic compounds(VOC) present in or generated by many sources, can be toxic, mutagenic or even carcinogenic, so that control of such emissions is significant. The 6 chlorinated organic chemicals as VOC were examined in this study. Prediction of the behavior of VOC on activated carbon beds is an important part of control system design. The objective of this study was to predict gas phase sorption isotherms from physical properties and liquid phase isotherms obtained with the same adsorbent and adsorbate. One of the techniques that was investigated was quantitative structure-activity relationships(QSAR) for the predicition procedures. It was possible to estimate sorption isotherms in the gas phase($a_g$) using either connectivity index, $^2{\chi}$, and the Henry's law coefficient ($H_a$) or the solubility and the equilibrium concentration in the gas phase. As a result of study, the predictive equation based on Freundlich model for $a_g$ was ${\log}\;a_g=0.238\;^2{\chi}+0.573\;{\log}\;H_a+4.330(r^2=0.94)$. Finally, this would provide a potentially useful tool to describe and predict sorption capacity without time-consuming tests.

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Detection of Hepatitis B Virus by LAMP and DHPLC (등온증폭반응법과 변성 고성능 액체 크로마토그래피를 이용한 B형 간염 바이러스의 검출)

  • Ahn, Young-Chang;Seo, Jae-Won;Choi, Jae-Gu;Jang, Won-Cheoul
    • Journal of the Korean Chemical Society
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    • v.55 no.2
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    • pp.262-267
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    • 2011
  • The denaturing high performance liquid chromatography(DHPLC) with fluorescence detector assay is very useful tool for detecting nucleic acids. Furthermore, loop-mediated isothermal amplification(LAMP) constitutes a potentially valuable tool for rapid diagnosis of pathogenic microorganisms. In this study, we evaluated the specificity, detection limit, and sensitivity of a LAMP method and DHPLC method for rapid detection of the hepatitis b virus(HBV). As a result, the LAMP assay reported here has the advantage of rapid detection whereas, DHPLC assay has more sensitivity than other assays. These findings suggest that LAMP and DHPLC assay may be good tool for rapid diagnosis of clinical HBV infection.

Henry성s law behavior on multilayer adsorption considered layer location dependence of the bonding energy (결합에너지의 층별 의존성이 고려된 다층흡착에서의 헨리법칙 거동)

  • 김철호
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.8 no.1
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    • pp.106-110
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    • 1998
  • 본 논문에서는 먼저 다층흡착에서 각 흡착층의 결합에너지가 서로 다른 경우의 흡착 등온선을 유도한다. 그리고 유도된 흡착등온식이 저압영역에서 헨리의 실험법칙을 잘 만족시킴을 보인다.

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