• 자원리싸이클링
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• 제15권5호
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• pp.3-10
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• 2006

자동차 폐촉매의 침출액으로부터 백금족 금속의 분리를 위하여 용매추출에 대한 기초연구가 수행되었다. 추출제로 tri-n-butyl phosphate (TBP), tri-n-octylamine (TOA) 그리고 di-n-hexyl sulfide (DHS)를 등유에 희석하여 사용하였다. 추출제의 종류 및 농도가 백금, 팔라듐 그리고 로듐의 추출거동에 미치는 영향을 조사하였다. 또한 세륨, 납, 철, 마그네슘 그리고 알루미늄 등 침출액에 존재하는 주요 금속불순물의 추출거동도 함께 조사하였다. TBP는 백금과 팔라듐, 그리고 TOA는 백금, 팔라듐, 로듐을 동시에 추출하였다. DHS 추출제인 SFI-6에 의한 용매추출 시 백금이 팔라듐과 함께 유기상으로 추출되었으나, SFI-6R은 팔라듐만 선택적으로 추출하였다. SFI-6R은 SFI-6에 비하여 팔라듐에 대한 선택성이 우수하였으나 추출속도가 느렸다. 추출제의 종류에 따라 백금족 금속과 함께 추출되는 금속불순물들이 달라지며 세정 또는 탈거공정에서 이들을 제거하여야 한다. 자동차 폐촉매의 침출액으로부터 백금, 팔라듐 그리고 로듐을 분리하기 위하여 먼저 DHS 추출제인 SFI-6R를 사용하여 팔라듐을 분리한 다음 TBP 또는 TOA으로 백금을 추출하여 로듐과 분리하는 공정이 적절한 것으로 나타났다.

• 한국식품영양과학회지
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• 제12권4호
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• pp.364-367
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• 1983

본실험(本實驗)은 번데기의 단백질(蛋白質) 최적(最適) 추출조건(抽出條件)을 검토하기 위하여 제사공장(製絲工場)에서 나온 탈지(脫脂)번데기를 oven-dry와 freeze-dry한 두 종류(種類)를 사용(使用)하여 추출성(抽出性)에 영향을 미치는 용매(溶媒)의 종류(種類), 추출용매(抽出溶媒)와의 혼합비율(混合比率), 온도(溫度) 및 시간(時間), 추출액(抽出液)의 pH의 영향 등을 검토하여 다음과 같은 결론(結論)을 얻었다. (1) 추출용매(抽出溶媒)에 따른 질소추출(抽出)은 0.05M NaOH에서 56%로 가장 많았으며 시료와 추출용매(抽出溶媒)와의 비율(比率)은 1 : 40일때가 질소추출(抽出)이 좋았다. (2) 추출(抽出)에 대한 온도(溫度)의 영향은 freeze-dry한 경우 $50^{\circ}C$, oven-dry한 시료가 $60^{\circ}C$에서 가장 많이 추출(抽出)되어 거의 90%까지 추출(抽出)이 가능하였으며 추출시간(抽出時間)은 10분 후 많은 차이(差異)를 나타내지 않았으나 60분에서 가장 높은 경향을 나타내고 있다. 일반적으로 freeze-dry한 번데기분(粉)은 oven-dry한 것보다 질소의 추출성(抽出性)이 약간 좋은 결과(結果)를 나타내었다. (3) 추출(抽出)에 미치는 pH의 영향은 pH 1.0에서 pH 11.0까지는 20%이하로 그 추출도(抽出度)가 낮았으나 pH 11.0이상에서 추출도는 급격히 증가(增加)하여 pH 13.0에서 60%이상 추출(抽出)이 가능하였다.

• Bulletin of the Korean Chemical Society
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• 제32권11호
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• pp.3979-3990
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• 2011

Eight ionizable nano-baskets of cone 25,26-di(carboxymethoxy)calix[4]arene-crown-3,4,5,6 were synthesized and were verified by $^1H$ and $^{13}C$ NMR spectroscopy, IR spectroscopy and elemental analysis. The competitive solvent extractions of alkali and alkaline earth metal cations were studied using such nano-baskets. The novelty of this study is including three binding units of calixarene's bowl, crown ether's ring and electron-donor ionizable moieties in a unique scaffold to assess the binding tendency towards the cations. The objective of this work is to study the extraction efficiency, selectivity and $pH_{1/2}$ of such complexes. The result of solvent extraction experiments indicated that these compounds were effective extractants of alkali and alkaline earth metal cations. Their selectivities were greatly influenced by the acidity of solution and the conformations of the calixcrown. One conformer was selective to $Na^+$ in pH ${\geq}$ 4, while the other was highly selective to $Ba^{2+}$ in pH 6 and upper.

• KSBB Journal
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• 제14권5호
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• pp.566-571
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• 1999

최근 들어 카르복실산 중에서 lactic acid는 생분해성 고분자의 원료물질로서 주목받고 있다. 본 연구에서는 혼합 3차 amine 추출제를 이용한 반응추출을 통해 lactic acid를 정제하였다. 다양한 TPA/TOA 혼합비에 따라 lactic acid의 분배계수를 얻었으며 그 결과 8:2의 혼합비에서 최대의 분배계수를 얻을 수 있었다. 또한 발효조에서 생산되는 lactic acid를 대상으로 하였을 때 혼합 3차 amine을 사용할 경우 추출효율이 90% 이상이 되는 것을 볼 때 본 연구에서 사용된 혼합 3차 amine이 발효 lactic acid의 정제에 적합한 추출제임을 알 수 있었다.

• 한국토양비료학회지
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• 제47권6호
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• pp.518-524
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• 2014

Heavy metal pollution in agricultural field near at the abandoned metal mines has been a critical issue in Korea. In particular, bioaccumulation in plants can have detrimental effect on human health. Main objective of this research was to examine arsenic (As) concentration in soil with varied extraction methods and to determine bioaccumulation and biological transfer factor in different crops. Results showed that bioaccumulation ratio of As for total contents in soil was ordered leafy and stem vegetables (1.19%) > fruit bearing vegetables (0.79%) > pulses (0.40%) > root vegetables (0.36%) with different crop species. Among 6 different extraction methods, all of extraction methods showed high correlation ($R^2=0.87-0.97$) except DTPA ($R^2=0.25$) when comparing As concentration in soil extracted with different extractants and As concentration in each crops. Calculated biological transfer factor was ranged 0.002-0.018 depending on crop species. Overall, concentration of As in crops can be varied and best management practice for minimizing bioaccumulation of As should be considered depending on crop species.

• 한국환경과학회지
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• 제24권1호
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• pp.1-7
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• 2015

The solid-phase extractant PS-D2EHPA/TBP was prepared by immobilizing two extractants D2EHPA and TBP in polysulfone (PS). The prepared PS-D2EHPA/TBP was characterized by using fourier transform infrared spectrometer (FTIR) and scanning electron microscopy (SEM). The removal of Cu(II) from aqueous solution was investigated in batch system. The experiment data were obeyed the pseudo-second-order kinetic model. Equilibrium data were well fitted by Langmuir model and the removal capacity of Cu(II) by solid extractant PS-D2EHPA/TBP obtained from Langmuir model was 3.11 mg/g at 288 K. The removal capacity of Cu(II) was increased according to increasing pH from 2 to 6, but the removal capacity was decreased below pH 3 remarkably.

• 패션비즈니스
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• 제18권4호
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• pp.15-27
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• 2014

A natural colorant was extracted from Acer ginnala, Alnus japonica and gromwell as extractants. Studies have been made on the effects of the kind of extracts and dyeing/mordanting conditions on colorimetric changes of ramie fabrics. The color of fabrics tended to become darker as the numbers of dyeing process and mordanting process increased using three kinds of extracts. As the numbers of dyeing and mordanting increased, the ramie fabrics gradually increased to show reddish and bluish signs using Acer ginnala, Alnus japonica, and gromwell extracts(500ml and 1,000ml). In the case of 1,500ml of gromwell extracts, the ramie fabrics showed the color with more redness and yellowness. Color difference (${\Delta}E$) of dyed and mordanted fabrics increased as the numbers of dyeing and mordanting processes increased. The apparent colors of ramie fabrics using Acer ginnala were Y and GY. The Alnus japonica extracts produced Y and GY colors on ramie fabrics. With varying amount of gromwell extracts, the colors of dyed and mordanted fabrics were R, YR, GY, G, PB, P and RP, however, the main color was PB. It was concluded that the extracts of Acer ginnala, Alnus japonica and gromwell can be used as a natural dye producing black colors.

• 자원리싸이클링
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• 제22권2호
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• pp.3-10
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• 2013

인듐은 희유금속으로 주로 ITO제조에 사용된다. 본 총설에서는 인듐을 함유한 2차자원을 침출한 용액으로부터 인듐을 분리하기 위한 용매추출, 이온교환 및 석출법에 대한 공정 조건 및 장단점을 조사했다. 보통 정도의 산성용액에서 인듐의 추출제로 D2EHPA가 가장 많이 사용되고 있으며, 매우 강한 염산용액에서는 아민계 추출제가 사용된다. 일반적으로 이온교환수지의 인듐 흡착량이 낮으므로, 인듐의 농도가 낮은 경우에 한해 이온교환은 용매추출보다 장점이 있다.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2454-2458
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• 2007

Exploring the basic concepts for the design of CO2-philic molecules is important due to the possibility for “green” chemistry in supercritical CO2 as substitute solvent systems. The Lewis acid-base interactions and C?H…O weak hydrogen bonding were suggested as two key factors for the solubility of CO2-philic molecules. We have performed high level quantum mechanical calculations for the van der Waals complexes of CO2 with trimethylphosphate and trimethylphosphine oxide, which have long been used for metal extractants in supercritical CO2 fluid. Structures and energies were calculated using the MP2/6-31+G(d) and recently developed multilevel methods. These studies indicate that the Lewis acid-base interactions have larger impact on the stability of structure than the C?H…O weak hydrogen bonding. The weak hydrogen bonds in trimethylphosphine oxide have an important role to the large supercritical CO2 solubility when a metal is bound to the oxygen atom of the P=O group. Trimethylphosphate has many Lewis acid-base interaction sites so that it can be dissolved into supercritical CO2 easily even when it has metal ion on the oxygen atom of the P=O group, which is indispensable for a good extractant.

• 한국환경과학회지
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• 제24권7호
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• pp.841-849
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• 2015

The solid phase extractant SAN-D2EHPA/TBP containing two extractants of Di-(2-ethylhexyl)phosphoric acid (D2EHPA) and Tri-butyl-phosphate (TBP) was prepared by immobilizing two exractants D2EHPA and TBP in styrene acrylonitrile copolymer (SAN). The prepared SAN-D2EHPA/TBP was characterized by using fourier transform infrared spectrometer (FTIR) and scanning electron microscopy (SEM). The solid phase extractant SAN-D2EHPA/TBP was tested for the removal of Cu(II) from aqueous solution. Experiments were carried out as a function of the pH and Cu(II) concentration in the aqueous phase. The equilibrium time was 180 min and equilibrium experiment data obeyed the pseudo-second-order kinetic model. The Langmuir isotherm model represented the experiment data as well. The maximum removal capacity of Cu(II) calculated from Langmuir isotherm model was 3.1 mg/g.