• Membrane Journal
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• v.25 no.4
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• pp.320-326
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• 2015

In this study, permeation experiments were carried out using the symmetric and asymmetric sinusoidal flux continuous operation (SFCO) modes for the submerged flat sheet membrane in the 0.5 wt% emulsion type cutting oil solution. The effective area and nominal pore size of the used microfiltration membrane were $0.02m^2$ and $0.15{\mu}m$, respectively. The emulsion cutting oil was rejected over 99% based on turbidity. Transmembrane pressure increased lower as the aeration rates increased. The symmetric SFCO mode was a little more effective than the symmetric SFCO mode in low permeate flux between 10 and $15L/m^2{\cdot}h$. However, the symmetric SFCO mode was shown very effectively in high permeate flux between 25 and $30L/m^2{\cdot}h$.

• Membrane Journal
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• v.20 no.2
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• pp.151-158
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• 2010

This paper presents the synthesis of ampholyte immobilized hollow-fiber membranes and adsorption characteristic of metallic ions. This is prepared by radiation induced grafting polymerization of an epoxy group containing Glycidyl methacrylate (GMA) onto an existing polyethylene porous hollow-fiber membrane. Ampholyte ion-exchanged alkalic group, $-NH_2$ (amine function) of Taurine (TAU) is reacted with glycidyl of GMA for the synthesis of stable membrane. However, Sodium sulfite (SS) membrane is also prepared by making chemical bonds with GMA of porous hollow-fiber membrane for the comparison of adsorption characteristic of metallic ions. These are called as TAU and SS membranes, respectively. It is shown that TAU membrane shows a steady flux, 0.9 m/h regardless of the density of TAU, while the flux of SS membrane decreases rapidly as the density of $SO_3H$ group increases. SS membrane showed a negligible flux. TAU membrane with the density 0.8 mmol/g shows the amount of metallic ions adsorbed in the following order, Cu > Cd > Mg > Sb > Pb. In general, TAU membrane with high density and reaction time showed the high amount of metallic ions adsorbed and flux.

• Membrane Journal
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• v.16 no.1
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• pp.68-76
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• 2006

This is the research about the concentration of trace citrus flavor components in water by pervaporation. We have investigated the permeation characteristics depending on the material and formation of membranes using four siloxane-based polymer composite membranes. We have also chosen the optimal membrane and investigated the permeation characteristics depending on the feed temperature, concentration and flow rate. And then it has been analyzed by using resistance-in series model. In the permeation experiment of citrus essence aroma model solution through the four siloxane-based polymer composite membranes, PVDF/POMS membranes have showed the best flavor flux and enrichment factor. As a result of the permeation experiment depending on the feed temperature, concentration and flow rate, we can find that as the feed temperature and concentration increase, the flavor flux increases while the enrichment factor decreases. And the flavor flux and enrichment factor increased as the flow rate increases.

• Membrane Journal
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• v.11 no.4
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• pp.179-189
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• 2001

Effect of ozonation on permeate flux was studied by using polysulfone ultrafiltration membrane. The filtration was first carried out by permeating phenol solutions under 3$kg_{f}$/$cm^2$ until steady-state flux was obtained. Then, the ozone of concentration range between 10 and 45 mg/1.min was ozonated in water for reducing the fouling on the UF membrane. Treatment of chemical wastewater by combined ozone and membrane filtration methods was also investigated for the final purpose. The Fenton method assisted by chemical coagulation was employed as a prtreatment method and found to be highly efficient in removing a large amount of organic compounds. And it was found that the ozonation made the permeate flux enhance in the phenol solution and phenolic-chemical wastewaster by 10% and oxidation by ozone and hydrogen peroxide was more effective. Evidence was presented that TMP decreased in more ozone concentrated water and it was found that the ozone-mediated membrane would have a limited role to prevent the membrane fouling rather than to eliminate fully.

• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.703-710
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• 2011

As the spacer in the membrane module provide the channel space to flow the feed solution smoothly and induce the flow turbulence, it could help to reduce both the concentration polarization and to take the long-term operation of membrane modules with high permeate flux by mixing the accumulated contaminants on the membrane surface into the bulk solution. In this study, the concentration distribution in membrane module with respect to the spacers which have the cross-sectional shapes of circle, cross, diamond and hexagon, the angles of spacer configuration, solute rejection and permeate flux were interpreted and optimized numerically using the "COMSOL Multiphysics" software. The concentration on the membrane surface was kept the lowest level for the cross-shape among the above four types of spacers. Also the 30 degree spacer configuration was showed as the most efficient case. The concentrations on the membrane surface at the module outlet for without spacer and the cross shape with the 30 degree spacer configuration were 2.09 and 1.29 times higher than those at inlet, respectively. The reduction effect of concentration polarization increased rapidly as the permeate flux increased.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05b
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• pp.153-155
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• 2004

상전이법으로 제조된 비대칭막은 세공의 크기를 nm이하의 수준으로 줄여 주면 막 여과저항이 크게 증가하여 경제성이 떨어지는 문제점을 가지고 있다. 이에 대한 대안으로 복합막이 제조되어 사용되고 있는데, 복합막은 우수한 투과도와 높은 배제율을 달성하기 위한 적극적인 대안이 되고 있다. 정수처리 및 수질환경 분야에 사용되는 나노복합막의 경제성을 더욱 향상시키기 위해서는 나노막의 투과유속을 증가시켜야 하는데, 복합막의 투과 성능은 지지체의 특성과 스킨층을 형성시키는 기술에 의해 좌우된다.(중략)

• Clean Technology
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• v.5 no.2
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• pp.25-35
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• 1999

Behavior of permeate flux decline was examined through the hollow fiber membrane in ultrafiltration system for Si colloidal solution. Flux decline with time was due to the growth of Si cake deposited on the membrane surface and the pore blocking by Si particles for the hollow fiber membrane. At the pseudo steady state of operation, the permeate flux of dead-end flow was 60 % to that of the cross flow. The ratio of permeate flux to the pure water flux, $J/J_w$, decreased with increasing the trans-membrane pressure, from 64.2 % for $0.5kg_f/cm^2$ to 45.7 % for $2.0kg_f/cm^2$. When the feed flow rate was 3 L/min, the pore blocking model was dominant at the initial period of filtration and was followed by the cake filtration model. And with increasing the feed flow rate from 1 L/min to 3 L/min, $R_c$ was $1.79{\times}10^{12}{\sim}2.34{\times}10^{12}m^{-1}$ which was the about 40 % decreased value to that of the 1 L/min while $R_p$ was not changed and was $1.71{\times}10^{12}m^{-1}$ approximately.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.5
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• pp.959-970
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• 2000

A laboratory-scale experiment was conducted to investigate the effect of soluble microbial products(SMP) on permeate flux in the submerged membrane separation activated sludge process. Continuous and batch filtration test were operated to understand mechanism of relationship between membrane fouling and SMP. Synthetic wastewater(phenol) was used as a carbon source. Hydraulic retention time(HRT) and mixed-liquor volatile suspended solids(MLVSS) of the reactor were kept at 12 hours and 9.000mg VSS/L, respectively. Batch filtration tests ($J_{60}/J_o$) using the mixed liquor from reactor showed that the increase of accumulated SMP concentration in the reactor caused to the decreasing permeate flux and the increasing of the adhesion matters which form cake and gel layer. The resistance value of cake layer was measured $2.9{\times}10^{10}{\sim}4.0{\times}10^{10}(1/m)$, this value showed more significant effect on flux drop than that of among other resistance layers. Batch phenol-degradation experiment was conducted to observe SMP type expected $SMP_{nd}$ and $SMP_{e}$ (SMP resulted from endogenous cell decomposition), these are non-biodegradable high molecular weight organic matter and playa significant role in permeate flux drop. Also, SMP concentration was accumulated as increased of HRT against flux drop.

• Membrane Journal
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• v.12 no.3
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• pp.158-164
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• 2002

This study was carried out the fundamental experiment to investigate the pervaporation process through NaA zeolite membrane for recycling the wasted isopropyl alcohol(IPA) in semiconductor cleaning processes. The NaA zeolite membrane used showed the excellent separation performance for full range of feed concentration and at high temperature operation. At 80 in operation temperature and 90 wt% IPA in feed concentration the separation performance was obtained about $1,500 g/m^2/hr$ in the permeation flux and more than 1,000 in the separation factor. In continuous operation of dehydration of IPA the average permeation flux was obtained about $1,000 g/m^2/hr$ at 80 and 90 wt% IPA feed concentration.

• Membrane Journal
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• v.24 no.5
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• pp.367-374
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• 2014

In the present study, disc-type LSCF/GDC (20 : 80 vol%) dual-phase membranes having porous LSC/GDC (50 : 50 vol%) active layers were prepared and effect of active layers on oxygen ion transport behavior was investigated. Introduction of active layers improved drastically oxygen flux due to enhanced electron conductivity and oxygen surface exchange activity. As firing temperature of active layer increased from $900^{\circ}C$ to $1000^{\circ}C$, oxygen flux increased due to improved contact between membrane and active layer or between grains of active layer. The enhanced contact would improve oxygen ion and electron transports from active layer to membrane. Also, as thickness of active layer increased from 10 to $20{\mu}m$, oxygen flux decreased since thick active layer rather prevented oxygen molecules diffusing through the pores. And, STF infiltration improved oxygen flux due to enhanced oxygen reduction reaction rate. The experimental data announces that coating and property control of active layer is an effective method to improve oxygen flux of dual-phase oxygen transport membrane.