• Applied Chemistry for Engineering
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• v.5 no.4
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• pp.681-697
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• 1994

The enzymatic hydrolysate of gelatin extracted from fish skin was fractionated and recycled through the membrane reactor according to the molecular weight for the purpose of using as functional material. In addition, the enzymatic hydrolysis conditions of gelatin, enzyme stability by membrane and mechanical shear, and effect on the long-term operational stability of the recycle membrane reactor were investigated. Using the pH-drop technique, Alcalase, pronase E and collagenase were identified as the most suitable enzymes for the hydrolysis of fish skin gelatin. The optimum hydrolysis conditions in the 1st-step membrane reactor(1st-SMR) by Alcalase were enzyme concentration 0.2mg/ml, substrate-to-enzyme ratio(S/E) 50(w/w), $50^{\circ}C$, pH 8.0, reaction volume 600ml and flow rate 6.14ml/min. In the 2nd-SMR by pronase E were enzyme concentration 0.3mg/ml, S/E 33(w/w), $50^{\circ}C$, pH 8.0, reaction volume 600ml and flow rate 6.14ml/min. In the case of 3rd-SMR, enzyme concentration 0.1mg/ml, S/E 100(w/w), $37^{\circ}C$, pH 7.5, reaction volume 600ml and flow rate 10ml/min. Decreased enzyme activities by mechanical shear and membrane were 30% and 15% in the 1st-SMR, were 14% and 5% in the 2nd-SMR, and 18% and 8% in the 3rd-SMR, respectively. Under the optimum conditions, the degree of hydrolysis in the 1st, 2nd and 3rd-SMR were 3.5%(Kjeldahl method, 87%), 3.1%(77%) and 2.7%(70%), respectively. The productivity of hydrolysate in the continuous three-step membrane reactor was 430mg per enzyme(mg) for 10 times of volume replacements.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.10a
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• pp.84-85
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• 1996

키틴은 자연계에 풍부하게 존재하는 다당류로서 이것을 이용하여 탈아세틸화된 형태인 키토산을 제조하였다. 키토산에는 히드록시기, 아민기 등 친수성 작용기들이 있어서 탈수용 분리막의 재료로서 많은 연구가 진행되어왔다. 함산소연료와 정밀화학제품의 원료로 쓰이는 MTBE(methyl t-butyl ether)는 methanol과 i-butylene을 합성시켜 만드는데 고순도의 MTBE를 얻기위해서는 미반응된 methanol의 분리, 제거가 필수적이다. 이에, methanol이 극성을 띄고 상대적으로 MTBE가 무극성인 것을 이용한 투과증발분리 연구가 진행되고 있다.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2001.05a
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• pp.178-180
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• 2001

본 혐기성 반응기와 호기성 반응기를 사용하여 염색폐수를 처리 할 경우 HRT 24~30시간의 경우 색도는 방류수 수질기준을 만족시킬 수 있으나 외관상 색도를 띄며, COD의 경우 배출수 허용기준을 만족시키기 어려우므로 전처리나 후처리로써 응집. 침전 공정, 오존 및 UV와 같은 고도산화공정이 필요하다고 사료되었다.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.10a
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• pp.130-132
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• 1998

정밀여과막(MF)막은 $0.1~1\mum$정도의 공경을 가지고 있는 막으로 산업이나 생활분야에서 널리 사용되고 있다. 이러한 정밀여과막에 이온교환기를 부여 시키므로써, 필요로하는 금속이온이나 단백질을 흡착할 수 있는 기능성 분리막이 제조 가능하다. 방사선프라프트 중합법은 고분자를 개질, 수식 또는 기능화시키는 수법으로 사용되고 있다. 본 실험에서는 방사선그라프트중합법을 사용하여 폴리에틸렌 정밀여과막에 에폭시기를 가지는 glycidyl methacrylate(GMA)를 그라프트 중합시킨 후 이온 교환기를 도입하여, 얻어진 막의 특성에 대해 고찰하였다. 본실험의 목적은 다음과 같다. (1) 폴리에틸렌 정밀여과 막에 방사선그라프트 중합법을 사용하여 이온교환기를 도입시키는 반응조건을 검토한다. (2) 도입된 이온교환기에 다른 막의 투과 성능을 조사한다. (3) 투과법에 의한 금속이온의 흡착성능을 조사한다. 여기서, 이온교환기로서는 술폰산(sodium sulfite:$SO_3H$)을 사용하였다.

• Membrane Journal
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• v.30 no.1
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• pp.1-8
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• 2020

In membrane bioreactor (MBR), activated sludge degrade the biological component and membrane process separate this bacterial flocks as well the suspended solids. However, membrane fouling is one of the major issues in MBR. In this review, composite membrane used in MBR to overcome fouling is discussed. It is classified into membrane containing carbon and noncarbon materials. Introducing graphene, graphene oxide (GO) and carbon nanotubes or their modified part into pristine membrane enhance hydrophilicity of the composite membrane. Inorganic materials like silicon dioxide (SiO₂) or titanium dioxide (TiO₂) are also incorporated for preparing composite membrane to increase its water flux.

• Journal of the Korean Vacuum Society
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• v.10 no.4
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• pp.440-448
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• 2001

The operation properties of DBD plasma reactors were observed by using 20 kV square pulse at the cylindrical and planar type of reactors in the condition of air pressure. The optimum operation frequency $f_0$ which optimizes the efficiency of operation was found as such $f_0\proptoexp(-C)$ when the current-voltage curve and charge-voltage curve were observed. Using these properties the dissipated power was evaluated. The dissipated power at the optimum frequency of operation was varied as the value of capacitance which is dependent on the structure and the dielectric material of the reactor, and had the maximum value at the specific value of capacitance. With these value of capacitance, DBD reactors which has a high level of efficiency can be formed.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.10a
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• pp.36-37
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• 1994

Sirkar등[1]이 많이 연구한 hollow-fiber contained liquid membrane방식보다 막내부에서의 물질전달 저항을 크게 낮출 수 있는 이른바 flowing liquid membrane방법을 Teramoto등[2]은 제안하였다. 좀더 발전된 membrane absorber방식으로서 평판형(flat-sheet type)막으로 흡수(absorption) 및 탈착(desorption)모듈을 구성하고, monoethanolamine 흡수제(absorbent)로 $Co_2/CH_4$ 분리에 적용하여 선택도를 크게 향상시킨 기존의 실험결과도 볼 수 있다. 막에서의 기-후 접촉과 반응이 수반된 물질전달에 의한 기체흡수 현상에 관해 많은 이론해석과 실험결과가 연구된 바 있다. 본 연구에서는 이산화탄소와 같은 산성기체(acid gas)의 분리에 주로 적용될 새로운 방식의 순환식 중공사막 흡수기 (circulatory hollow-fiber membrane absorber: HFMA)를 제안하고 이의 실제적용에 대한 기초로서 모델해석에 의한 분리성능을 예측하였다.

• Membrane Journal
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• v.2 no.1
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• pp.21-32
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• 1992

Hydrogen-permselective silica membranes were synthesized within tim walls of porous Vycor tubes by chemical vapor depostion of $SiO_2$. Film deposition was carried out using $SiCl_4$ hydrolysis either in the oppm shag reactants or in the one-sided geometry. At temperatures above $600^{\circ}C$ the permeation rate of hydrogen thorough the silica films varied between 0.01 and $025cm^3(STP)/cm^2-min-atm$ depending on the reaction geometry and the $H_2 : N_2$ permeation ratio was about 1000. Permeation rates of both $H_2$ and $N_2$ increased with increasing temperature. The silica membranes produced by one-sided deposition have higher hydrogen permmeation rates than those produced by the opposing reactants geometry although the membranes formed in an opposing reactants geometry were relatively stable during the heat treatment or after exposure to ambient air. These membranes can be applied to high temperature gas separations or membrane reactors once the film deposition process is optimized to get high permeability as well as good stability.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.101-109
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• 2005

In order to produce only a pH-controlled solution without discharging any unused solution, this work has developed a continuous electrolytic system with a pH-adjustment reservoir being placed before an ion exchange membrane-equipped electrolyzer, where as a target solution was fed into the pH-adjustment reservoir, some portion of the solution in the pH-adjustment reservoir was circulated through the cathodic or anodic chamber of the electrolyzer depending on the type of the ion exchange membrane used, and some other portion of the solution in the pH-adjustment reservoir was discharged from the electrolytic system through other counter chamber with its pH being controlled as acid or base. The phenomena of the pH being controlled in the system could be explained by the electro-migration of the ion species in the solution through the ion exchange membrane under a cell potential difference between anode and cathode and its consequently-occurring non-charge equilibriums and electrolytic water- split reactions in the anodic and cathodic chambers.

• Membrane Journal
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• v.6 no.4
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• pp.242-249
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• 1996

To improve pervaporation performance of water/ethanol mixtures, chitosan/poly(vinyl alcohol) blended and phosphorylated chitosan composite membranes were prepared. Chitosan/poly(vinyl alcohol) blends were prepared with various blend ratios and then crosslinked with glutaraldehyde by two methods. With increasing crosslinking agent content and crosslinking times separation factor increased and permeate flux decreased. Separation factor of the membrane which contains glutaraldehyde as a crosslinking agent was higher than that of the membrane surface crosslinked. Phosphorylated chitosan was prepared with various reaction times and composite membrane was prepared. As reaction times increased, the separation factor increased with high affinity for water.