• 한국환경과학회지
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• 제12권11호
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• pp.1173-1179
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• 2003

Laboratory sorption isotherm batch studies have been attempted to elucidate interaction of synthetic pyrethroids (bifenthrin and permethrin) with sediments and their fractions. As a nonlinear isothermal model, the Freundlich equation was applied to sorption results obtained from sediments to investigate the relationship between synthetic pyrethroids and sediments containing different amounts of organic carbon. Results demonstrated that the sorption capabilities of bifenthrin and cis- and trans-permethrin was in the order of bifenthrin, cis-permethrin and trans-permethrin, respectively, indicating that adsorbed bifenthrin was the most stable followed by cis- and trans-permethrin in all sediments. Their sorption capability was closely related to organic carbon contents in sediments. Higher sorption was observed in sediments containing higher organic carbon contents. Sorption study extended into the fractions, clay and humic acids, extracted from a sediment, indicated that higher sorption capacity in humic acids occurred than in the clay of both examined bifenthrin and permethrin. This study demonstrates the sorption of synthetic pyrethroids with sediments, and will help in the understanding of the transport and fate of synthetic pyrethroids existing in field sediments.

• 한국염색가공학회지
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• 제6권4호
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• pp.17-26
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• 1994

Poly(ethylene terephthalate)(PET) filaments were treated in binary mixtures of organic solvents such as benzyl alcohol/perchloroethylene(BA/PER), benzyl alcohol/trichloroethylene(BA/TRI), benzyl alcohol/ethylene chloride(BA/EC), methanol/perchloroethylene (ME/PER), and methanol/trichloroethylene(ME/TRI). From the equilibrium swelling of PET, total and partial isotherms of PET for sorption of solvent mixtures and isotherms for distribution of the components between the phases were taken. Also the shrinkage and the crystallinity of PET treated with binary mixtures were investigated. The results obtained were summerized as follows: 1. All isotherms for distribution of the components between the phase deviated from the diagonal in system of PET-binary mixtures. Especially in the binary mixtures of ME/PER or ME/TRI, selectivo sorption of chlorinated hydrocarbon PER and TRI by PET occured. 2. The shrinkage of PET treated in binary mixrures was increased to compare with single solvent-treated, but the composition of binary mixtures corresponding to maximum values of shrinkage was not always agreed with the composition of binary mixtures corresponding to maximum values of shrinkage was not always agreed with the composition of binary mixtures exhibiting of the maximum swelling of PET. 3. The crystallinity of PET treated in binary mixtures generally increased than that of single solvent-treated.

• 한국축산식품학회지
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• 제18권4호
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• pp.285-291
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• 1998

Adsorption isotherms of water vapour for infant formula milk powders manufactured by P. M. and N company in Korea were measured at temperatures between 20, 30 and 40$^{\circ}C$ using COST-90 modified method. Results showed that the isotherms were sigmoidal in shape. The adsorption isotherms of milk powder were depending on the temperature and products. The BET-model were applied and analyzed to compare the experimental value. It was found that the BET-model is fitted with measuring data. Sample P showed the lowest monolayer value and sample N showed the highest. Isosteric heat obtained upon application of BET-model was calculated in this field of temperature using the Clausius-Clapeyron equation. It is suggested that the usage of the BET-model to estimate the heat of water sorption in infant formula milk powder should be in agreement with the results from COST-90 project.

• Environmental Engineering Research
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• 제14권1호
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• pp.26-31
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• 2009

Sorption of $Ni^{2+}$ in aqueous solution was studied using montmorillonite. The experimental and equilibrium data fitted well to the Langmuir isotherm model. From the kinetics data for nickel sorption onto montmorillonite, the diffusion of $Ni^{2+}$ inside the clay particles was the dorminant step controlling the sorption rate and as such more important for $Ni^{2+}$ sorption than the external mass transfer. $Ni^{2+}$ was sorbed due to strong interactions with the active sites of the sorbent and the sorption process tends to follow the pseudo second-order kinetics. Thermodynamic parameters (${\Delta}G^{\circ},\;{\Delta}H^{\circ},\;{\Delta}S^{\circ}$) indicated a non spontaneous and endothermic adsorption process while the positive low value of the entropy change suggests low randomness of the solid/solution interface during the uptake of $Ni^{2+}$ by montmorilionite. Heavy metals such as $Ni^{2+}$ in aqueous bodies can effectively be sorbed by montmorillonite.

• 한국식품저장유통학회지
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• 제21권3호
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• pp.334-340
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• 2014

볶음온도에 따른 옥수수 분말의 흡습특성을 구명하기 위하여, 옥수수 낟알을 160, 180, 200, 220, $240^{\circ}C$에서 20분간 볶은 후 분쇄하고, $20^{\circ}C$에서 각 분말의 수분활성도($a_w$) 0.11, 0.33, 0.53, 0.75, 0.90에 따른 평형수분함량(EMC)을 측정하여 등온흡습곡선을 작성하였다. 볶은 옥수수 분말의 등온흡습곡선은 $a_w$ 증가에 따른 EMC 증가가 전형적인 sigmoid 형태를 보였으며, $a_w$ 0.53 이상의 영역에서는 동일 $a_w$에서 볶음온도가 고온일수록 높은 EMC를 나타내었다. 옥수수 분말의 등온흡습곡선은 볶음온도의 뚜렷한 영향이 없이 Oswin, Caurie, Henderson, Halsey 모델로 설명이 가능하였으며, 가장 적합한 모델은 Oswin인 것으로 나타났다. 단분자층 수분함량은 전범위의 $a_w$영역에서 GAB 방정식으로 예측할 수 있었으며, 볶음온도가 높아짐에 따라 증가하는 경향을 보여서 $180^{\circ}C$에서는 0.043 kg $H_2O/kg$ solids, $240^{\circ}C$에서는 0.053 kg $H_2O/kg$ solids을 각각 나타내었다. 이로써 옥수수의 볶음온도가 분말의 $20^{\circ}C$ 흡습특성에 영향을 미치는 것으로 확인되었다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.125-130
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• 2004

This study has been assessed the influence of applying sewage sludge to soil amendments on the sorption properties, and leaching potential of three commonly used organophosphorus pesticides, Diazinon, Fenitrothion, and Chlorpyrifos. A sandy soil with a low content of organic carbon was treated with sewage sludge with a ratio sandy soil : sludge ratio of 30:1. The sorption was determined with the batch equilibrium technique. The sorption isotherms could be described by Freundlich equation. The Freundlich constant, K value which measures sorption capacity, were 3.97, 9.94, 22.48 for Diazinon, Fenitrothion, Chlorpyrifos in non-amended soil. But in amended soil, K value was 12.58, 28.47, and 61.21 for Diazinon, Fenitrothion, and Chlorpyrifos. The overall effect of sewage sludge addition to soil was to increase pesticides adsorption, due to the high sorption capacity of the organic matter. The effect of sludge on tile leaching of pesticides in the soil was studied using packed soil columns. Total recoveries of pesticides in soil and leachate with leaching in soil column, were in the range of about 73～84%, was reduced with the passage of time. Diazinon moved more rapidly than Chlorpyrifos in the unamended soil due to greater sorption and lower water solubility of Chlorpyrifos. Total amounts of pesticides leached from the sewage sludge amended soils were significantly reduced when compared with unamended soils. This reduction may be mainly due to and increase in sorption in amended soils, as a consequence of the increase in the organic matter content.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.339-339
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• 2006

In this study, the microvoids in glassy polymers were investigated by Xe sorption and $^{129}Xe$ NMR measurements. Xe sorption isotherms of glassy polymers have been successfully interpreted by the dual-mode sorption model. $^{129}Xe$ NMR chemical shift of the $^{129}Xe$ in the samples show nonlinear low-field shift with increasing sorption amount of Xe because of a fast exchange of Xe atoms between Henry and Langmuir sites, whereas it has showed linear shift against sorption amount of Xe into the Langmuir site. From this Xe-density dependence of the $^{129}Xe$ NMR chemical shift, it has been able to estimate mean size of the microvoids in glassy polymer. It is confirmed that there is correlation between ${C_H}'$ and volume or number of microvoids. From these findings, it is demonstrated that $^{129}Xe$ NMR spectroscopy is a powerful technique to determine the mean size and number of microvoids in glassy polymers.

• Journal of Radiation Protection and Research
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• 제15권2호
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• pp.7-16
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• 1990

알우미나, 실리카겔, 제오라이트 3A, 카오린 그리고 나트륨-벤토나이트에 대한 방사성코발트 및 루테늄 흡착을 수소이온농도, 핵종 농도 그리고 이온강도를 함수로 고찰하였다. 토양에 대한 코발트 및 루테늄의 지연계수는 공극율 측정으로 결정하였다. 코발트 및 루테늄의 가수분해 분자종은 물리적 흡착반응으로 고체 표면과 상호작용한다. 코발트 및 루테늄의 후로인드릿히 흡착 등온식은 직선이다. 코발트 및 루테늄의 흡착은 이온강도의 증가에 따라 감소한다. 지연계수에서 공극율 증가효과는 분배계수의 증가효과와 반한다.

• 한국염색가공학회지
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• 제2권2호
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• pp.33-38
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• 1990

Nitrocellulose [NC]-Poly(vinylamine) [PVAm] blended membranes with the change of amino group contents were prepared. The sorption and permeation of a mono-sulfonic acid dye, Orange II, in the membranes were investigated by the steady-state permeation method at $50^{\circ}C$ and pH 2.2. The results were discussed in the framework of dual sorption and diffusion theory. It was found that thesorption isotherms comprise a partition and two Langmuir type adsorption having similar binding constants. One of the latter sorption modes is due to unknown adsorption sites in NC and the other is due to the amino groups in PVAm. Apparent diffusion coefficients for collective P and L dye species, $D_P\; and D_L$, were obtained. Interpretation of $D_P$ values leads to two modes of partitions; one is such that dye is immobilized in NC and the other is the dissolution of the dye into the internal water phase.

• 한국식품과학회지
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• 제15권4호
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• pp.315-320
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• 1983

본(本) 연구(硏究)에서는 국내(國內)에서 아직 조사(調査)되지 않은 16개 품목(品目)의 농산물(農産物)에 대(對)한 등온흡습곡선(等溫吸濕曲線)을 측정온도(測定溫度), $25^{\circ}C,\;30^{\circ}$, 및 $45^{\circ}C$ 에서 결정(決定)하였다. 온도범위(溫度範圍) $25^{\circ}{\sim}45^{\circ}C$ 사이에서는 온도(溫度)의 증가(增加)에 따라 평형수분함량(平衡水分含量)이 감소(減少)하는 경향을 보였다. 또한 등온흡습곡선(等溫吸濕曲線)의 측정치(測定値)로 부터 BET단분자막수분함량(單分子膜水分含量)을 분석(分析), 결정(決定)하였다. 등온흡습기작(等溫吸濕機作)의 열역학적(熱力學的) 함수인 엔트로피의 변화(變化)는 건조식품(乾燥食品)의 안전저장(安全貯藏) 수분함량(水分含量)영역인 BET단분자막수분함량(單分子膜水分含量)과 밀접한 관계(關係)에 놓인 것으로 사료되고 있다.