• Membrane Journal
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• v.8 no.2
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• pp.102-108
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• 1998

Permeation behavior of the semiconductor rinsing wastewater containing Si particles was examined by ultrafiltration using the polysulfone plate membrane. The permeation flux was gradually decreased with time. It was due to the growth of cake deposited on the membrane surface and the pore plugging by Si particles. Permeation flux of cross flow type was 1.4 times higher than that of the dead end flow type. Nitrogen back flushing which is the removing method of membrane fouling was superior to the water sweeping. With nitrogen back flushing, the decrease of permeation flux due to the fouling was recovered about 85 % to the initial flux in the flat plate membrane system. The rejection rate of Si particles was about 90 % and the size of Si particle in the permeate was about 70 nm.

• Membrane Journal
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• v.15 no.1
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• pp.52-61
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• 2005

Permeate flux decline in a microfiltration was analyzed by measuring the permeability of bentonite colloidal solution through polyethylene capillary membranes. The flux decline with time was due to the growth of cake layer on the membrane surface and to the pore blocking by particles. As the time approaches to steady state, the permeate flux is almost controlled by the cake filtration model. Faster flux decline at high trans-membrane pressure was attributed to the formation of denser packed cake layer and pore blocking. The ratio of permeate flux to the initial permeate flux, J/J₁, decreased with increasing the trans-membrane pressure, from 45% for 0.5 kg/sub f//㎠ to 38% for 2.0 kg/sub f//㎠. In comparing the ratio of each fouling component to the total fouling for the 0.5 kg/sub f//㎠ TMP condition, complete blocking was 23.4%, standard blocking was about 14.6% and cake filtration was 62.0%, respectively. Permeate flux through the membrane increases with cross flow velocity, and the effect of the variation of velocity is more significant at 1.0 kg/sub f//㎠ rather than at 2.0 kg/sub f//㎠ of the operation pressure. Permeate flux for the membrane having the average pore diameter of 0.34 ㎛ was higher than that for the membrane of 0.24 ㎛ pore size, with the higher flux with the low concentration of feed. On the operation using the membrane of 0.34 ㎛ pore, the pore blocking in the low concentration of 200 ppm is negligible relative to the pore blocking in the 1000 ppm feed.

• Membrane Journal
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• v.23 no.2
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• pp.185-188
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• 2013

This study was carried out for microfiltration tubular membrane module equipped with self-designed air injection nozzle in order to determine the permeate flux due to the effect of membrane fouling reduction. The 0.1 wt% yeast particle solution was used as a feed solution and permeation tests were performed for the cases with and without air injection. Permeation fluxes were measured and analyzed to examine the effect of membrane fouling reduction. While the permeation flux without air injection decreased continuously, that with air injection was improved more than 30 percent than that of no air injection case.

• Membrane Journal
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• v.18 no.2
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• pp.168-175
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• 2008

This study was carried out for the plate and frame membrane modules equipped with and without plastic protuberances on the support frame in order to determine the effect of eddy flow induced by the protuberances on permeate flux. The initial time for rapidly declined permeate flux on the module with protuberances was delayed twice or more than that on the module without protuberances when kaolin solution was permeated at the operating pressures from 0.4 to 1.6 bar. Also decreasing ratio of the kaolin solution to pure water flux for module with protuberances was 1 to 5% lower than that for module without protuberances. The flux improvement due to protuberances at laminar flow corresponding Reynolds number 1,750 was about double as compared with that in the transition flow region. In general, the kaolin fouling reduction for the plate module with protuberances during initial filtration process was very effective, even though the permeate flux after 60 minutes filtration did not increase significantly.

• Membrane Journal
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• v.4 no.1
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• pp.38-45
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• 1994

The experiment was conducted to evaluate the effects of variables in preparing TFC membrane by interfacial polymerization. Obtained results are as follow: As the concentration of MPD increses, the rejection rate incresed, the total volume flux was decresed. As the dipping time in MPD solution increases, the rejection rate increased, the total volume flux was increased until reach optimum point. As the dipping time in TMC solution increses, the total volume flux increased, the rejection rate was increased until reach optimum point. As the curing temperature increases, the total volume flux increased was an optimum point in the rejection rate. Since the quantity of generating hydrochloric acid was small, the required quantity of NaOH for neutriliztion was small. The post-treatment with ethanol, isopropanol and water in the temprerature ranging of $5~7^{\circ}C$ brought an increment of the rejection and the total volume flux, For water temperature ranging of $5~7^{\circ}C$was the optimum temperature in the post treatment.

• Membrane Journal
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• v.19 no.4
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• pp.285-290
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• 2009

The permeation experiments were carried out for the nominal pore size $0.1\;{\mu}m$ and 5 mm inner diameter microfiltration tubular membrane equipped with self-designed discharging rod in order to determine the effect of fouling reduction. Dioctyl tinoxide (DOTO) latex particle was used to prepare up to 0.5 wt% concentration of feed solution, and the experiments were operated within 1.6 bar. The permeation flux effect on the discharged rod was measured as a result of flux comparison between the cases of equipped and non-equipped discharge rod modules for every experiment. The permeation flux for the case using the discharged rod was enhanced to 20% at 1.6 bar operating pressure. The improvement on permeation flux for using the discharged rod was greater as the concentration of feed increased, and reached up to 43% under 0.5 wt% concentration of feed solution.

• Proceedings of the Membrane Society of Korea Conference
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• 1997.04b
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• pp.39-39
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• 1997

김치산업에서 원재료의 염적공정중에 발생하는 폐염적수를 처리하여 염적공정에 재사용하는 새로운 시스템을 개발하였다. 관형 정밀여과막을 사용한 본 연구에서 막오염의 감소와 높은 막투과유속의 유지를 위하여 산역세척과 투과수역세척이 도입되었고 대상이 되었던 세공크기가 비슷한 4종류의 막(Carbosep M14, Membralox Z100, Membralox A200, Microdyne MD020TP 2N)에 대하여 역세척의 효율이 각각 다르게 나타났다. 특히 지르코니아 재질의 막 표면과 탄소재질의 지지체로 이루어진 Carbosep M14 세라믹막은 투과수역세척시에 역세척을 하지 않았을 때 보다 오히려 투과유속이 감소하는 특이한 현상이 관찰되었고 이러한 역세척 효율의 차이의 원인을 규명하기위한 연구가 진행되었다. 4종류의 막에 대하여 전처리된 폐염적수의 여과시 진행되는 막오염 메카니즘을 알아보기 위하여 문헌에서 잘 알려진 4가지의 여과모델식을 적용하여 보았고 직렬여과저항모델을 이용하여 여과저항을 세분하여 측정하였다. 모델식의 적용결과 역세척의 효율이 좋은 3종류의 막에는 막표면의 케이크형성이 주된 투과유속의 감소원인임을 알아내었고 carbosep M14 막은 용존유기물의 비가역적인 흡착과 세공막힘이 주된 원인임을 알 수 있었다.

• Membrane Journal
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• v.10 no.3
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• pp.155-162
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• 2000

The reverse osmosis membrane housing(HY) was developed for excellent distribution of a feed solution, and the separation performance was compared with the commercialized Rochem(RC) system. The permeation flux of HY system was a little lower than that of RC system. On the other hand, the NaCl rejection ra4io was generally higher. Also, the permeation flux and rejection ratio for type A, B and C modules(disc plate and frame type) were measured using NaCl, sucrose and butanol solutions. The separation performance of type C module for NaCL and sucrose solutions was the most effective, and then those of type A and B were followed, respectively. However, the separation performance for butanol solution was type B, C and A order. The flux improvement ratio of type B to A increased as butanol concentration decreased or operating pressure increased up to 28 bar.

• Membrane Journal
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• v.6 no.3
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• pp.182-187
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• 1996

Hydrophilic poly(acrylonitrile) [PAN] membrane with good molecular weight cut-off characteristics were prepared by using the phase inversion method. Permeability and molecular weight cut-off of the membranes were measured through the ultrafiltration test. On the surface of the PAN support membranes, poly(acrylic acid) [PAA] was deposited by dip-coating. The water permeability of the PAN support membrane had $0.17~31\textrm{mm}^3/m^{2} \cdot s \cdot Pa$, the molecular weight cut-off 42, 000~150, 000. The transport characteristics of the prepared composite membranes were significantly affected by the variation of the support membrane mophology. The permeability of the composite membrane was decreased with increasing molecular weight cut-off of the support membrane, and the separation factor was slightly changed depending on the feed concentration.

• Membrane Journal
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• v.9 no.3
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• pp.185-192
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• 1999

The ultrafiltration characteristics of wafer processing wastewater produced from semicon¬ductor industry was investigated for wastewater reuse. Using the pilot-scale ultrafiltration system con¬taining poly sulfone hollow fiber membranes (MWCO : 10,000, 20,000, 30,(00), the membrane performance, such as flux, rejection rate and concentration factor for flux was examined. The SDhs, turbidity, electrical conductivity and concentration of Si particles were measured, and the possibility of permeate reuse was validated from the experimental results. It was shown that the flux was recovered by the sweeping with air and water effectively. The permeate flux of 30,000 MWCO membrane was about 5 times higher than that of 10,000 and 20,000 MWCO membranes. The concentration of Si particle in the saw wastewater was analyzed 3.8-5.6 mg/$\ell$ and that of Si particle in the permeate was analyzed less than 0.2${\mu}g$/$\ell$. This means the rejection of silicon particle was over 96%.