• 한국수소및신에너지학회논문집
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• 제32권4호
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• pp.197-204
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• 2021

Pressure swing adsorption is a purification process which can get pure hydrogen. The purification process is composed of four process: compression, adsorption, desorption and discharge. In this study the adsorption process was simulated by using the Fluent and validated with experimental results. A gas used in experiment is composed of H₂, CO₂, CH₄, and CO. Adsorption process conducted under 313 kelvin and 3 bar and bituminous-coal-based (BPL) activated carbon was used as the adsorbent. Langmuir model was applied to explain the gas adsorption. And diffusion of all the gases was controlled by micro-pore resistances. The result shows that, the most adsorbed gas was carbon dioxide, followed by methane and carbon monoxide. And carbon monoxide took the least amount of time to reach the maximum adsorption amount. The molar fraction of the off-gas became the same as the molar fraction of the gas supplied from the inlet after adsorption reached the equilibrium.

• KSBB Journal
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• 제14권5호
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• pp.611-615
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• 1999

우리나라 인근 해역에서 가장 쉽게 채취할 수 있는 해조류 중의 하나인 S. sagamianum을 이용한 Pb의 생체흡착 실험을 수행하였다. Pb는 1시간 내에 흡착 평형에 도달하였으며, Pb의 평형흡착량은 각각 224.5 mg Pb/g biomass 였다. Pb 흡착시에 경금속인 Ca 및 Mg가 500 mg/L 이하로 존재할 때 Ca는 약간 흡착되었으나 Mg는 전혀 흡착되지 않아 Pb만을 선택적으로 제거하는 것이 가능하였다. Pb 흡착 후에 0.1M HCl, 0.1M HNO$_3$,0.1M EDTA 및 0.1 M NaOH를 이용하여 탈착 실험을 수행하고 다시 재흡착을 시키는 과정을 6회 반복한 결과, 탈착율은 EDTA가 100%로 가장 높았으나, S. sagamianum의 재생성을 고려해 볼 때 HNO$_3$및 HCl가 효과적인 탈착 용액인 것으로 사료되었다. 특히 HNO$_3$를 이용하였을 때 Pb의 누적흡착량이 736.8 mg/g biomass로서 가장 높은 것을 알 수 있었다. 이러한 결과로 부터 S. sagamianum 은 매우 우수한 생체흡착제로 연속공정에 사용이 가능할 것으로 사료되었다.

• Journal of Radiation Protection and Research
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• 제8권1호
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• pp.15-25
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• 1983

Ru-103, Cs-137 그리고 Ce-144를 차례로 분리하는 방법을 유기양이온 교환체 Amberite CG-120, 무기이온 교환체, silica gel과 montmorillonite를 가지고 검토하였다. Amberite CG-120으로 Ru-103, Cs-137 그리고 Ce-144를 흡착 및 탈착하는 최적조건은 각각 0.01M-, 0.01M-, 0.1M-HCl과 3M-, 3M-, 5M-HCl이다. Silica gel로 Ru-103, Cs-137 그리고 Ce-144를 흡착 및 탈착하는 최적 조건은 각각 pH 8, pH 8, pH 8과 3M-, 1M-, 1M-HCl이다. Montmorillonite로 Ru-103, Cs-137 그리고 Ce-144를 흡착 및 탈착하는 최적 조건은 각각 pH 8, 0.01M-HCl, pH 4와 1M-, 5M-, 3M-HCl이다. 낮은 이온강도에서 일어나는 흡착 그리고 탈착 이온강도의 차이는 연속적인 실험에서 혼합핵종의 분리를 위하여 이용된다. Ru-103, Cs-137 그리고 Ce-144 혼합물의 개별분리는 Amberite CG-120, silica gel에서보다 montmorillonite에서 더욱 효과적이다.

• 공업화학
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• 제28권5호
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• pp.539-546
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• 2017

본 연구는 산성유해가스 제거를 위한 고효율 음이온교환 복합 폼 화학필터를 제조하기 위하여 폴리우레탄(PU) foam에 다른 종류의 PSA를 사용하여 상용이온교환수지를 부착하여 제조, 이의 내수성, 내화학성, 접착신율, 농도와 유속에 따른 HCl과 HF의 흡착특성에 관하여 연구하였다. 그 결과 접착신율은 ATE-701은 900%, AT-4000C는 1,500%, HCA-1000는 2,400%이며, 내수성 및 내화학성평가에서 HCA-1000의 탈리율이 6% 미만으로 우수한 내구성을 가짐을 확인하였다. HCl, HF의 농도와 유속이 증가함에 따라 흡착이 빠르게 일어났으며 유속과 농도에 관계없이 110 min 이후 100% 흡착파과평형이 일어남을 확인할 수 있었다. 또한 SEM Morphology 관찰 결과 점착제가 고르게 분산되어 있고 이온교환수지의 다공구조가 유지되었으며, 흡-탈착 공정에서 성능저하가 없는 것으로 보아 내구성이 있음을 확인하였다.

• 자원리싸이클링
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• 제25권4호
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• pp.60-67
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• 2016

본 연구에서는 P507을 포함하고 있는 추출수지를 사용하여 중희토류 원소인 Gd, Tb, Dy의 흡 탈착 반응 메커니즘을 고찰하고 분리를 위한 최적 크로마토그래피법의 반응조건을 도출하였다. 흡 탈착 반응 메커니즘은 흡착등온식인 Langmuir, Freundlich 흡착등온식과, 흡착속도모델인 유사 1차, 2차 반응속도식을 적용하여 고찰하였다. 중희토류 원소의 흡착반응은 단분자층으로 일어난다고 가정하여 흡착등온식을 적용하였고, 잘 일치하여 흡착반응이 단분자층으로 이루어짐을 추측할 수 있었다. 시간별 실험을 진행하여 유사 1차, 2차 반응속도식에 적용한 결과 유사 2차 반응속도식이 추출수지의 중희토류 흡착 메커니즘을 더 잘 표현하였고, 평형흡착량의 실험값은 이론값에 부합하였다. 크로마토그래피법을 이용하여 용리액 HCl 0.25 M 농도조건에서 ${\alpha}^{Tb}_{Gd}=1.24$, ${\alpha}^{Dy}_{Tb}=1.03$으로 분리계수 1이상의 높은 분리조건을 확인하였다. HCl 용리액을 사용하였을 때, 용리액의 농도가 높을수록 분리도는 감소하고 용출구간은 줄어드는 경향을 확인하였다.

• Korean Journal of Chemical Engineering
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• 제35권11호
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• pp.2198-2206
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• 2018

We addressed the development of a novel, low-cost, and high-efficient material from hybrid materials, known as microcapsules. Microcapsules are a composite adsorbent made of a mixture of tannin, sericite and chitosan. The FT-IR analysis showed that the microcapsules contain hydroxyl, carboxyl, carbonyl, and amino groups, which play an important role in the adsorption of heavy metals. The microcapsules were able to remove 99% of Pb(II) in 30 min, and obtained a removal efficiency of more than (13-50)%, compared with the single adsorbents of tannin, chitosan, and sericite. In adsorption kinetic analysis, pseudo-second-order adsorption was more suitable than pseudo-first-order adsorption, and chemical adsorption did not limit the adsorption rate of Pb(II) ion. In isothermal adsorption, Langmuir adsorption was more suitable than Freundlich adsorption, and the maximum Langmuir adsorption capacity was 167.82 (mg/g). Furthermore, desorption and reusability studies, as well as the applicability of the material for wastewater treatment, demonstrated that microcapsules offer a promising hybrid material for the efficient removal of significant water pollutants, i.e., Pb(II) from aqueous solutions.

• Membrane and Water Treatment
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• 제7권6호
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• pp.521-537
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• 2016

Laboratory-scale experiments were carried out to investigate the adsorption equilibrium, the adsorption kinetics and facilitated transport of two cationic dyes (Methylene Blue (MB) and Rhodamine B (RB)) on Polymer Inclusion Membrane (D2EHPA-PIM). Different adsorption isotherms (Freundlich, Langmuir and Temkin models) as well as kinetics models indicated that the adsorption process is spontaneous and exothermic. Under the optimal conditions, the adsorption removal efficiencies reach about 93% and 97% for MB and RB respectively. Different extraction values by D2EHPA-PIM were obtained for the two cationic dyes: MB is weakly extracted at pH 2.0 (E% = 18.7%) whilst E% = 82.4% was observed for RB at the same pH. This difference was exploited in a mixture containg both the 2 cationic dyes for the selective extraction of RB at pH 2. Desorption of both dyes was achieved from the membrane by using acidic aqueous solutions and desorption ratio up to 90% was obtained. The formulas of the extracted complexes by the PIMs were, determined by the method of slopes. The dyes transport was elucidated using mass transfer analysis where in it found relatively high values of the initial flux ($J_0$) as 41.57 and $18.74{\mu}mol.m^2.s^{-1}$ for MB and RB respectively.

• Bulletin of the Korean Chemical Society
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• 제28권8호
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• pp.1375-1382
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• 2007

A column preconcentration method with pulverized Amberlite XAD-4 loaded with bismuthiol I (BI) has been developed for the determination of trace Cd(II) and Cu(II) in various real samples by flame atomic absorption spectrophotometry. Various experimental conditions, such as the size of XAD-4, adsorption flow rate, amount of bismuthiol I, stirring time for adsorbing bismuthiol I on XAD-4, pH of sample solution, amount of XAD-4- BI, desorption solvent, and desorption flow rate, were optimized. Also, the adsorption capacity and the adsorption rate of Cd(II) and Cu(II) on XAD-4-BI were investigated. The interfering effects of various concomitant ions were investigated, Bi(III), Sn(II) and Fe(III) were found to affect the determination. But the interference by these ions was completely eliminated by adjusting the amount of XAD-4-BI resin to 0.70 g, although the adsorption flow rate was slower. For Cd(II) our proposed technique obtained a dynamic range of 0.5-40 ng mL-1, a correlation coefficient (R2) of 0.9913, and a detection limit of 0.3 ng mL-1. For Cu(II), the corresponding values were 2.0-120 ng mL-1, 0.9921 and 1.02 ng mL-1. To validate this proposed technique, the aqueous samples (stream water, reservoir water, tap water and wastewater), the diluted brass sample and the plastic sample, as real samples, were used. Recovery yields of 91-103% were obtained. These measured data were not different from ICP-MS data at 95% confidence level. Our proposed method was also validated using rice flour CRM (normal, fortified) samples. From the results of our experiment, we found that the technique we present here can be applied to the determination of Cd(II) and Cu(II) in various real samples.

• 자원리싸이클링
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• 제22권1호
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• pp.55-63
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• 2013

SCR 탈질 폐촉매 내에는 바나듐, 텅스텐 등 고가의 희유금속이 포함되어 있어 분리 및 회수가 필요하다. 본 연구에서는 바나듐 및 텅스텐 등의 희유금속을 함유하고 있는 SCR 탈질 폐촉매에서 바나듐을 회수하기 위하여 ammonium metavanadate를 사용하여 상용 음이온교환수지인 MP600에 의한 흡탈착실험을 실시하였다. 실험결과 초기 pH의 영향에 대해 pH 2 ~ 6에서 음이온화가 활발하여 높은 흡착율을 보였으며, 반응온도가 높아짐에 따라 흡착속도가 향상되는 경향을 보였으나 최대흡착량은 온도의 영향을 받지 않았다. 탈착에 대한 pH의 영향은 pH 1.0 이하의 강산성 및 pH 13.0 이상의 강염기성에서 높은 탈착율을 보였으나 pH 3.0 ~ 11.0 에서는 탈착율이 낮거나 거의 이루어지지 않았다. 흡착평형실험에 따른 흡착등온식은 Freundlich 흡착등온식에 적합하였으며, 반응 시간에 따른 흡착반응속도는 pseudo-second-order로 잘 모사되었다. 또한 Dubinin-Radushkevich, Temkin 흡착등온식을 통하여 흡착 에너지를 평가하였다.

• Advances in nano research
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• 제9권3호
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• pp.173-181
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• 2020

Adsorption and heterogeneous electro-Fenton process using iron-loaded ZSM-5 nano-zeolite were investigated for the removal of Tetracycline (TC) from wastewater. The nano-zeolite was synthesized hydrothermally and modified through impregnation. The zeolite was characterized by XRD, FT-IR, FE-SEM, N₂ adsorption-desorption, and NH₃-TPD techniques. The equilibrium data were best represented by the Freundlich isotherm. The pseudo-second-order kinetic model was the most accurate model for the adsorption of TC on the modified nano-zeolite. The effect of parameters such as pH of solution and current density were investigated for the heterogeneous electro-Fenton process. The results showed that the current density of 150 mA and pH of 3 led to the highest TC removal (90.35%) at 50 min. The nano-zeolite showed the appropriate reusability. Furthermore, the developed kinetic model was in good agreement with the removal data of TC through the electro-Fenton process.