• Clean Technology
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• v.7 no.4
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• pp.265-272
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• 2001

본 연구는 지구 온난화 현상의 주원인이 되는 $CO_2$ 를 화력발전소 연도가스로부터 분리 회수하기 위한 PSA 공정 개발용 기초자료를 습득하기 위하여 실시하였다. 연도가스와 유사한 조건하에서 국내에서 제조된 활성탄을 이용하여 이산화탄소 및 밸런스를 이루고 있는 질소 가스의 흡착평형 및 흡착속도 실험을 실시하였으며, 분석을 위하여 자체 제작한 장치(부피측정법) 및 TGA 장치를 각각 사용하였다. 이 연구에서 획득한 흡착등온선으로부터 사용된 흡착제가 이산화탄소의 분리에 적절한지 판단할 수 있었다. 또한, TGA에 의해 측정된 흡착속도 자료는 향후 사용될 흡착탑의 파과곡선 예측에 사용될 수 있다. 연구결과로부터 다음과 같은 사실을 알 수 있었다. 첫째, 낮은 흡착온도 일수록 흡착량이 많고 빠른 흡착속도를 나타내었다. 둘째, 압력이 높아질수록 흡착량은 증가하였다. 셋째, SGT활성탄이 SGA-100 및 SGP-100활성탄 보다 다소 많은 흡착량과 빠른 흡착속도를 보였다.

• Proceedings of the KAIS Fall Conference
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• 2008.11a
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• pp.411-414
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• 2008

본 논문에서는 $CO_2$ 분리용 활성탄의 표면분석 및 흡착속도를 비교하였다. TGA 방법에 의한 흡착속도 데이터를 획득함으로써 분리장치 설계를 위한 기초자료를 획득하였고, 흡착온도에 따른 결과는 흡착온도가 낮을수록, 흡착량이 증가하고 흡착속도 또한 더 빠름을 알 수 있었다.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.11
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• pp.804-811
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• 2011

The aim of this study is to evaluate the applicability of adsorption models for understanding adsorption properties of adsorbents. For this study, the adsorption charateristics of $NO_3^-$ by commercial anion exchange resin, PA-308, were investigated in bach process. The adsorption kinetic data for $NO_3^-$ by anion exchange resin showed two stage process comprising a fast initial adsorption process and a slower second adsorption process. Both the pseudo-first-order kinetic model and the pseudo-second-order kinetic model could not be used to predict the adsorption kinetics of $NO_3^-$ onto anion exchange resin for the entire sorption period. Only the fast initial portion ($t{\leq}20min$) of adsorption kinetics was found to follow pseudo-first-order kinetic model and controlled mainly by external diffusion that is very fast and high, whereas, the slower second portion (t > 20 min) of adsorption kinetics seems to be controlled by a second-order chemical reaction and by intraparticle diffusion.

• Korean Journal of Ecology and Environment
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• v.36 no.3 s.104
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• pp.295-303
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• 2003

Sorption kinetics of hydrophobic organic compounds (chlorobenzene and phenanthrene) in natural wetland soils was investigated using laboratory batch adsorbers. One -site mass transfer model (OSMTM) and two compartment first-order kinetic model (TCFOKM) were used to analyze sorption kinetics. Analysis of OSMTM reveals that apparent sorption equilibria were obtained within 10 to 75 hours for chlorobenzene and 2 hours for phenanthrene, respectively. For chlorobenzene, the sorption equilibrium time for surface soil was longer than that of deeper soil presumably due to physico-chemical differences between the soils. For phenanthrene, however, no difference in sorption equilibrium time was observed between the soils. As expected from the number of model parameters involved, the three-parameter TCFOKM was better than the two-parameter OSMTM in describing sorption kinetics, The fraction of fast sorption ($f_1$) and the first-order sorption rate constants for fast ($k_1$)and slow ($k_2$) compartments were determined by fitting experimental data to the TCFOKM. The results of TCFOKM analysis indicate that the sorption rate constant in the fast compartment($k_1$) was much greater than that of slow fraction($k_2$) . The fraction of the fast sorption ($f_1$) and the sorption rate constant in the fast compartment($k_1$) were increasing in the order of increasing $k_{ow}$, phenanthrene > chlorobenzene. The first-order sorption rate constants in the fast ($k_1$) and slow ($k_2$) compartments were found to vary from $10^{-0.1}\;to\;-10^{1.0}$ and from $10^{-4}\;to-10^{-2}$, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.11
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• pp.1238-1243
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• 2005

The batch experiments of biosorption were carried out for the removal of lead ion from metal solution using Laminaria japonica and Kjellmaniella crassifolia, two species of marine algaes as biosorbent. We have investigated biosorption kinetics and equilibrium of lead by using marine algaes. We observed that biosorption of lead occurred very rapidly by marine algaes ; the biosorption reached equilibrium less than 2 hr. These experimental data could be accurately described by a pseudo-second-order rate equation, obtaining values between $0.883{\times}10^{-3}$ and $0.628{\times}10^{-3}\;g/mg/min$ for the biosorption rate constant $k_{2,ad}$. It could be described with Langmuir, Redlich-Peterson, and Koble-Corrigan(Langmuir-Freundlich) equation. The biosorption capacity by L. japonica and K. crassifolia were in the sequence of Pb>Cd>Cr>Cu and Pb>Cu>Cd>Cr, respectively. The biosorption capacity of L. japonica were increased with pH increasing.

• Journal of Sericultural and Entomological Science
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• v.33 no.1
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• pp.9-12
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• 1991

A study on dyeing-rate for single and mixture dyeing of silk with acid dyes was carried out. Single and mixture dyeings were performed with levelling and milling dyes at 7$0^{\circ}C$ and at pH 3, pH 4 and pH 5, respectively. The results of this study were summerized as follows : 1. C. I. Acid Orange 7. A) At pH 3, dyeing-rate was more fast in the single dyeing than in mixture dyeing at the beginning of dyeing process. B) At pH 4 and 5, dyeing-rates tend to get very similar in single and mixture dyeing. 2. C. I. Acid Blue 138 A) At all pH value, dyeing-rates were more fast in the mixture dyeing than single dyeing at the beginning of dyeing. B) As the time increased, the difference of dyeing-rate and adsorption amounts between single and mixture dyeing was not shown.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.8
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• pp.450-457
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• 2015

In this research a adsorbent, PVA-Zeolite bead, was prepared by immobilizing zeolite with PVA. The results of XRD and SEM analysis showed that the prepared PVA-Zeolite beads had porous structure and the zeolite particles were in mobilized within the internal matrix of the beads. The adsorption properties of Sr ion and Cs ion with the adsorbent were studied by different parameters such as effect of pH, adsorption rate, and adsorption isotherm. The adsorption of Sr ion and Cs ion reached equilibrium after 540 minutes. The adsorption kinetics of both ions by the PVA-Zeolite beads were fitted well by the pseudo-second-order model more than pseudo-first-order model. The equilibrium data fitted well with Langmuir isotherm model. The maximum adsorption capacities of Sr ion and Cs ion calculated from Langmuir isotherm model were 52.08 mg/g and 58.14 mg/g, respectively. The external mass transfer step was very fast compared to the intra-particle diffusion step in the adsorption process of Cs ion and Sr ion by the PVA-Zeolite beads. This result implied that the rate controlling step was the intra-particle diffusion step.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.689-697
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• 1998

In this work, we studied the equilibrium, rate and rate determining step of uranium adsorption on RGP resins of MR type prepared by varying the degree of crosslinking and the amount of diluent. The equilibrium of uranium adsorption on RGP resins were well explained by Frendrich isotherm as well as Langmuir isotherm model. The amount of adsorption and adsorption rate increase with the adsorption temperature. The heat of the adsorption was 11 kcal/mol. The adsorption rates of uranium on RGP resins were decreased in the order of RGP-10(50)>RGP-1(50)>RGP-2(50)>RGP-5(50)>RGP-0(50) and RGP-2(75)>RGP-2(100)>RGP-2(50)>RGP-2(30)>RGP-2(0). The diffusion resistance of uranium into RGP resin increased as follows; molecular diffusion < pore diffusion < surface diffusion. On the other hand, the surface diffusion was more dominative than the pore diffusion in intraparticle region. Thus, this result indicates that the adsorption mechanism of uranium on RGP resins is intraparticle diffusion controlled.

• Journal of the Korean Vacuum Society
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• v.14 no.4
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• pp.171-179
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• 2005

The influence of the surface roughness and the porosity on the apparent sticking coefficient of the getter was determined quantitatively by Monte Carlo simulation. The sorption characteristics of the getter was investigated by solving numerically the particle balance equation depending on the sticking probability and diffusivity.

• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.125-130
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• 2010

In the present work, we have investigated the adsorption efficiency of carbon/iron oxide nanocomposite towards removal of hazardous brilliant green (BG) from aqueous solutions. Carbon/iron oxide nanocomposite was prepared by chemical precipitation and thermal treatment of carbon with ferric nitrate at $750^{\circ}C$. The resulting material was thoroughly characterized by TEM, XRD and TGA. The adsorption studies of BG onto nanocomposite were performed using kinetic and thermodynamic parameters. The adsorption kinetics shows that pseudo-second-order rate equation was fitted better than pseudo-first-order rate equation. The experimental data were analyzed by the Langmuir and Freundlich adsorption isotherms. Equilibrium data was fitted well to the Langmuir model with maximum monolayer adsorption capacity of 64.1 mg/g. The thermodynamic parameters were also deduced for the adsorption of BG onto nanocomposite and the adsorption was found to be spontaneous and endothermic.