고체상 추출제로서 폴리비닐알콜에 테노일트리플루오로아세톤과 트리옥틸포스핀 옥사이드를 고정화한 폴리비닐알콜 겔비드의 제조와 수중의 구리이온 제거 특성

유해나(Hae-Na You),이민규(Min-Gyu Lee) 한국청정기술학회 2014 청정기술 Vol.20 No.3

테노일트리플루오로아세톤(thenoyltrifluoroacetone, HTTA)과 트리옥틸포스핀옥사이드(trioctylphoshineoxide, TOPO)를 폴리비닐알콜(poly vinyl alcohol, PVA)로 고정화한 PVA 겔 비드를 제조하고, 이를 사용하여 수중의 Cu<SUP>2+</SUP>를 제거하였다. 제조한 PVA 겔 비드의 Cu<SUP>2+</SUP> 제거특성은 유사 2차 속도식에 잘 적용되었으며, 랑미어 등온식에서 구한 Cu<SUP>2+</SUP>의 최대 제거량은 9.59mg/g이었다. Cu2+ 제거의 최적 pH 범위는 pH 3.5~6이었다. PVA겔 비드를 5차례 재사용한 경우에도 추출제의 손실이나 PVA겔 비드의 손상은 관찰되지 않았다. PVA gel beads were made by immobilization of thenoyltrifluoroacetone (HTTA) and trioctylphoshineoxide (TOPO) with poly vinyl alcohol (PVA). The prepared PVA gel beads were used for the removal of Cu<SUP>2+</SUP> from aqueous solution. The removal characteristics of Cu<SUP>2+</SUP> by PVA gel beads was found to follow the pseudo-second-order kinetic equation. The maximum removal capacity calculated from Langmuir isotherm equation was 9.59 mg/g. The optimal pH was in the range of 3.5~6. Even when the PVA gel beads were reused 5 times, the leakage of extractant and the damage of PVA gel beads was not observed.

습식혼합에 의한 리튬망간 산화물의 합성과 리튬이온 제거특성

유해나(Hae-Na You),이동환(Dong-Hwan Lee),이민규(Min-Gyn Lee) 한국청정기술학회 2013 청정기술 Vol.19 No.4

본 연구에서는 탄산리튬과 탄산망간을 사용하여 습식혼합방법으로 스피넬 리튬망간 산화물(LMO)을 합성하였다. 합성한 리튬망간 산화물의 물리적인 특성은 X-선 회절 분석기(X-ray diffraction, XRD)와 주사전자현미경(scanning electron microscopy, SEM) 사용하여 분석하였다. 회분식 실험을 통해 LMO의 리튬이온에 대한 흡착특성을 살펴보았다. Langmuir 흡착 등온식으로부터 구한 리튬의 최대흡착량은 27.21 mg/g였다. LMO는 뛰어난 리튬 이온체의 특성을 가지고 있었으며, Ca<SUP>2+</SUP> < K<SUP>+</SUP> < Na<SUP>+</SUP><Mg2+ < Li<SUP>+</SUP> 순서로 분배계수(Kd)가 나타나 해수로부터 리튬을 회수하는데 용이할 것으로 사료된다. In this paper, the wet mixing method was introduced to prepare spinel lithium manganese oxide (LMO) with Li₂CO₃ and MnCO₃. The physical properties of the resulting lithium manganese oxide were characterized by the XRD and SEM. The adsorption properties of LMO for Li+ were investigated by batch methods. The maximum adsorption capacity of lithium was calculated from Langmuir isotherm and found to be 27.25 mg/g. The LMO are found to have a remarkable lithium ion-sieve property with distribution coefficients (Kd) in the order of Ca<SUP>2+</SUP> < K<SUP>+</SUP> < Na<SUP>+</SUP> < Mg<SUP>2+</SUP> < Li<SUP>+</SUP>, which is promising in the lithium extraction from seawater.

폴리우레탄 폼에 LMO를 고정화하여 리튬이온 회수를 위한 새로운 PU-LMO 흡착제의 제조

유해나(Hae-Na You),이민규(Min-Gyu Lee) 한국청정기술학회 2014 청정기술 Vol.20 No.3

본 연구에서는 EVA를 바인더로 사용하여 우레탄 폼(PU)에 LMO를 고정화한 PU-LMO를 제조하였다. XRD 및 SEM 분석을 통해서 EVA에 의해 LMO가 폴리우레탄에 잘 고정화된 것을 확인할 수 있었다. PU-LMO를 제조시에 EVA/LMO의 최적비율은 0.26이었다. PU-LMO에 의한 리튬이온의 흡착 속도는 유사 2차 속도 모델식에 잘 부합하였다. 평형실험 데이터는 Langmuir 흡착 등온식에 잘 적용되었으며, 최대 흡착량은 17.09 mg/g이었다. PU-LMO는 리튬이온에 대한 분배계수(Kd)가 다른 금속들의 Kd 값에 비해 높게 나타나 뛰어난 리튬 이온 선택성과 높은 흡착량을 보였다. In this study, PU-LMO was made by immobilization of LMO on urethane foam (PU) with using an EVA as a binder. PU-LMO was characterized by using X-Ray Diffractometer (XRD) and Scanning Electron Microscopy (SEM). The optimal ratio of EVA/LMO for preparation of PU-LMO was 0.26 gEVA/gLMO. The adsorption of lithium ions by PU-LMO was found to follow the pseudo-second-order kinetic model. The equilibrium data fitted well with Langmuir isotherm model and the maximum removal capacity of lithium ions was 17.09 mg/g. The PU-LMO was found to have a remarkably high selectivity of lithium ions and high adsorption capacity because the distribution coefficient (Kd) of lithium ion was higher than those of other metal ions.

Al(OH)3를 PVC로 고정화한 PVC-Al(OH)3 비드의 제조와 수중의 불소 이온의 흡착 특성

유해나 ( Hae Na You ),감상규 ( Sang Kyu Kam ),이민규 ( Min Gyu Lee ) 한국환경과학회 2014 한국환경과학회지 Vol.23 No.5

In order to remove fluoride ions from aqueous solution, PVC-Al(OH)3 beads were prepared by immobilizing Al(OH)3 with polyvinyl chloride (PVC). The prepared PVC-Al(OH)3 bead was characterized by using SEM, EDS and Zeta potential. Dependences of pH, contact time and initial fluoride concentration on the adsorption of fluoride ions were studied. The optimal pH was in the range of 4~10. The adsorption was rapid during the initial 12 hr, and equilibrium was attained within 72 hr. The adsorption rate of fluoride ions by PVC-Al(OH)3 beads obeyed the pseudo-second-order kinetic model. The maximum adsorption capacity obtained from Langmuir isotherm model was found to be 62.68 mg/g.

강산성 양이온 교환수지를 충전한 고정층에서 리튬이온의 제거특성

유해나(Hae-Na You),이민규(Min-Gyu Lee) 한국청정기술학회 2014 청정기술 Vol.20 No.2

강산성 양이온 교환수지를 충전한 고정층 컬럼을 사용하여 수중의 리튬이온을 제거하는 연속식 실험을 수행하였다. 층 높이, 유입 유량 및 유입 농도와 같은 파라미터들을 살펴보았으며, 파과곡선으로부터 파과시간(t0.05), 포화시간(t0.95) 및 제거된 리튬이온의 총량(mtotal)을 구하였다. 실험 결과 t0.05와 t0.95는 층 높이가 감소함에 따라 감소하였고, 유입 농도와 유입 유량이 증가함에 따라 감소하였다. mtotal은 유입 유량과 층 높이가 증가함에 따라 증가하였지만, 유입 유량이 증가함에 따라서는 감소하였다. 실험자료를 토마스 모델식과 윤-넬슨 모델식을 적용한 결과, 토마스 모델식이 파과 데이터에 잘 부합하였다. The continuous experiments were carried out using fixed-bed column packed with strong-acid cation exchange resin for the removal of lithium ions from aqueous solution. The parameters such as bed height, flow rate and inlet concentration were investigated. Breakthrough time (t0.05), saturation time (t0.95), and total amount of lithium ion removed (mtotal) were obtained from the breakthrough curves. The results showed that t0.05 and t0.95 decreased with decreasing bed height, and decreased with increasing inlet concentration and flow rate. mtotal increased with increasing inlet concentration and bed height, but decreased with increasing flow rate. Thomas model and Yoon-Nelson model equations were applied to the experimental data, the results showed that the breakthrough data gave a good fit to Thomas model equation.

다이메틸설폭시화물 용매를 사용한 PVC-LMO 비드의 제조와 리튬 이온 흡착 특성

유해나(Hae-Na You),이동환(Dong-Hwan Lee),이민규(Min-Gyu Lee) 한국청정기술학회 2014 청정기술 Vol.20 No.2

본 연구에서는 노말 메틸 피로리돈(N-methyl-2-pyrrolidone, NMP)을 대신하여 다이메틸설폭시화물(dimethyl sulfoxide, DMSO)을 용매로 사용하여 폴리염화비닐 (poly vinyl chloride, PVC)로 리튬망간산화물(lithium manganese oxide, LMO)를 고정화하여 PVC-LMO 비드를 제조하였다. XRD 분석을 통해 PVC-LMO 비드내에 LMO가 잘 고정화 된 것을 확인 하였다. 합성한 PVC-LMO 비드의 크기는 약 4 mm였다. PVC-LMO 비드에 의한 리튬이온 흡착 실험은 회분식으로 수행하였다. 랭뮤어 모델식으로 부터 구한 최대 흡착량은 21.31 mg/g였다. PVC-LMO 비드에 의한 리튬이온 흡착특성은 유사 2차 속도모델식으로 잘 설명되었으며, 내부확산 단계가 흡착속도 결정단계인 것으로 사료되었다. In this study, PVC-LMO beads were prepared by immobilizing lithium manganese oxide (LMO) with poly vinyl chloride (PVC) diluted in dimethyl sulfoxide (DMSO) solvent on behalf of N-methyl-2-pyrrolidone (NMP). XRD analysis confirmed that LMO was immobilized well in PVC-LMO beads. The diameter of PVC-LMO beads synthesized by DMSO was about 4 mm. The adsorption experiments of lithium ions by PVC-LMO beads were conducted batchwise. The maximum adsorption capacity obtained from Langmuir model was 21.31 mg/g. The adsorption characteristics of lithium ions by PVC-LMO beads was well described by the pseudo-second-order kinetic model. It was considered that the internal diffusion was the rate controlling step.

활성탄을 충전한 고정층에서 페놀 흡착에 따른 파과곡선과 물질전달저항 해석

유해나 ( Hae Na You ),감상규 ( Sang Kyu Kam ),이민규 ( Min Gyu Lee ) 한국환경과학회 2014 한국환경과학회지 Vol.23 No.1

Adsorption of phenol on activated carbon in a fixed bed was studied. The effects of fixed-bed length, superficial velocity (flow rate) and particle size of adsorbent on fixed-bed performance were investigated. Some characteristic parameters such as the breakthrough time (t0.05), saturation time (t0.95), length of mass transfer zone (LMTZ), adsorptive capacity (W), and adsorption rate constant (Ka) were derived from the breakthrough curves. Adsorbent particle sizes significantly affected the shape of the breakthrough curve. Larger particle sizes resulted in an earlier breakthrough, a longer LMTZ and a lower adsorption rate. Superficial velocity was a critical factor for the external mass transfer during fixed-bed adsorption process. The external mass transfer resistance was dominant as increasing superficial velocity.

고체상 추출제로서 Polyvinyl Chloride에 D2EHPA를 고정화한 PVC-D2EHPA의 제조와 Cu(II) 제거 특성

감상규 ( Sang Kyu Kam ),유해나 ( Hae Na You ),이동환 ( Dong Hwan Lee ),이민규 ( Min Gyu Lee ) 한국환경과학회 2014 한국환경과학회지 Vol.23 No.6

The solid phase extractant (PVC-D2EHPA bead) was prepared by immobilizing di-2-ethylhexyl-phosphoric acid (D2EHPA) with polyvinyl chloride (PVC). The prepared PVC-D2EHPA beads were characterized by using fourier transform infrared spectrometer (FTIR) and scanning electron microscopy (SEM). The removal experiments of Cu(II) by PVC-D2EHPA beads conducted batchwise. The removal kinetics of Cu(II) was found to follow the pseudo-second-order model. The equilibrium data fitted well with Langmuir isotherm model and the maximum removal capacity was 2.6 mg/g at 20℃. The optimum pH region was in the range of 3.5 to 6. and the standard free energy (△Go) was between .4.67 ∼.4.98 kJ/mol, indicating the spontaneous nature of Cu(II) removal by PVC-D2EHPA beads.

Dioxane을 용매로 한 PVC-LMO 비드의 제조와 Li+ 흡착특성

감상규 ( Sang Kyu Kam ),유해나 ( Hae Na You ),이민규 ( Min Gyu Lee ) 한국환경과학회 2014 한국환경과학회지 Vol.23 No.7

In this study, PVC-LMO beads were prepared by immobilizing lithium manganese oxide (LMO) with poly vinyl chloride (PVC) diluted in dioxane solvent. XRD and SEM analysis confirmed that LMO was immobilized well in PVC-LMO beads. The diameter of PVC-LMO beads prepared by dioxane solvent was about 2 mm. The adsorption experiments of lithium ions by PVC-LMO beads were conducted batchwise. The optimum pH was pH 10. The adsorption characteristics of lithium ions by PVC-LMO beads was well described by the pseudo-second-order kinetic model. The maximum adsorption capacity obtained from Langmuir model was 24.25 mg/g. The thermodynamic parameters such as △H°, △S° and △G° were evaluated. The calculated ΔG° was between .6.16 and .4.14 kJ/mol (below zero), indicating the spontaneous nature of Li+ adsorption on PVC-LMO beads. Also, the results showed that PVC-LMO beads prepared in this study could be used for the removal of lithium ions from seawater containing coexisting ions such as Na+, K+, Mg2+ and Ca2+.

연구논문 : 활성탄의 물리적 특성과 표면 특성에 따른 수중의 methylene blue의 흡착특성

감상규 ( Sang Kyu Kam ),유해나 ( Hae Na You ),이민규 ( Min Gyu Lee ) 한국환경과학회 2014 한국환경과학회지 Vol.23 No.11

The adsorption characteristics of the methylene blue (MB) were studied using three activated carbons such as ACA and ACB with similar specific surface area (1,185 and 1,105 m2/g), and ACC with relatively high specific surface area (1,760 m2/g). The surface chemical properties of these activated carbons were investigated by X-ray photoelectron spectroscopy (XPS). The results indicated that ACA had more functional groups (with phenol, carbonyl, and carboxyl etc.) than ACB (with carbonyl and carboxyl) and ACC (with carboxyl). The isotherm data were fitted well by Langmuir isotherm model. The adsorption capacities of ACA, ACB, and ACC for MB were 454.7 mg/g, 337.7 mg/g, and 414.0mg/g, respectively. As phenol and carboxyl content of the surface on activated carbon increased, MB adsorption capacity was increased. Although ACA had a smaller specific surface area than ACC, the content of phenol and carboxyl group was abundant, so MB adsorption capacity was found to be higher than ACC.